X-Git-Url: http://git.cyclocoop.org/%22%20.%20generer_url_ecrire%28%22sites_tous%22%29%20.%20%22?a=blobdiff_plain;f=includes%2FContent.php;h=3bce48e710b7be829617b95c2bcc10082315c13f;hb=12166f46b4d63d3fd3cab68cf4c7090a1646dd09;hp=30e84006061d64a08209c4a078a650dd5fb58cd5;hpb=52abc24967c01d9f037ae108841d063ca722bf94;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/Content.php b/includes/Content.php
index 30e8400606..3bce48e710 100644
--- a/includes/Content.php
+++ b/includes/Content.php
@@ -1,618 +1,1482 @@
 <?php
+/**
+ * A content object represents page content, e.g. the text to show on a page.
+ * Content objects have no knowledge about how they relate to wiki pages.
+ *
+ * @since 1.WD
+ */
+interface Content {
+
+	/**
+	 * @since WD.1
+	 *
+	 * @return string A string representing the content in a way useful for
+	 *   building a full text search index. If no useful representation exists,
+	 *   this method returns an empty string.
+	 *
+	 * @todo: test that this actually works
+	 * @todo: make sure this also works with LuceneSearch / WikiSearch
+	 */
+	public function getTextForSearchIndex( );
+
+	/**
+	 * @since WD.1
+	 *
+	 * @return string The wikitext to include when another page includes this
+	 * content, or false if the content is not includable in a wikitext page.
+	 *
+	 * @TODO: allow native handling, bypassing wikitext representation, like
+	 *    for includable special pages.
+	 * @TODO: allow transclusion into other content models than Wikitext!
+	 * @TODO: used in WikiPage and MessageCache to get message text. Not so
+	 *    nice. What should we use instead?!
+	 */
+	public function getWikitextForTransclusion( );
+
+	/**
+	 * Returns a textual representation of the content suitable for use in edit
+	 * summaries and log messages.
+	 *
+	 * @since WD.1
+	 *
+	 * @param $maxlength int Maximum length of the summary text
+	 * @return   The summary text
+	 */
+	public function getTextForSummary( $maxlength = 250 );
+
+	/**
+	 * Returns native representation of the data. Interpretation depends on
+	 * the data model used, as given by getDataModel().
+	 *
+	 * @since WD.1
+	 *
+	 * @return mixed The native representation of the content. Could be a
+	 *    string, a nested array structure, an object, a binary blob...
+	 *    anything, really.
+	 *
+	 * @NOTE: review all calls carefully, caller must be aware of content model!
+	 */
+	public function getNativeData( );
+
+	/**
+	 * Returns the content's nominal size in bogo-bytes.
+	 *
+	 * @return int
+	 */
+	public function getSize( );
+
+	/**
+	 * Returns the ID of the content model used by this Content object.
+	 * Corresponds to the CONTENT_MODEL_XXX constants.
+	 *
+	 * @since WD.1
+	 *
+	 * @return String The model id
+	 */
+	public function getModel();
+
+	/**
+	 * Convenience method that returns the ContentHandler singleton for handling
+	 * the content model that this Content object uses.
+	 *
+	 * Shorthand for ContentHandler::getForContent( $this )
+	 *
+	 * @since WD.1
+	 *
+	 * @return ContentHandler
+	 */
+	public function getContentHandler();
+
+	/**
+	 * Convenience method that returns the default serialization format for the
+	 * content model that this Content object uses.
+	 *
+	 * Shorthand for $this->getContentHandler()->getDefaultFormat()
+	 *
+	 * @since WD.1
+	 *
+	 * @return String
+	 */
+	public function getDefaultFormat();
+
+	/**
+	 * Convenience method that returns the list of serialization formats
+	 * supported for the content model that this Content object uses.
+	 *
+	 * Shorthand for $this->getContentHandler()->getSupportedFormats()
+	 *
+	 * @since WD.1
+	 *
+	 * @return Array of supported serialization formats
+	 */
+	public function getSupportedFormats();
+
+	/**
+	 * Returns true if $format is a supported serialization format for this
+	 * Content object, false if it isn't.
+	 *
+	 * Note that this should always return true if $format is null, because null
+	 * stands for the default serialization.
+	 *
+	 * Shorthand for $this->getContentHandler()->isSupportedFormat( $format )
+	 *
+	 * @since WD.1
+	 *
+	 * @param $format string The format to check
+	 * @return bool Whether the format is supported
+	 */
+	public function isSupportedFormat( $format );
+
+	/**
+	 * Convenience method for serializing this Content object.
+	 *
+	 * Shorthand for $this->getContentHandler()->serializeContent( $this, $format )
+	 *
+	 * @since WD.1
+	 *
+	 * @param $format null|string The desired serialization format (or null for
+	 *    the default format).
+	 * @return string Serialized form of this Content object
+	 */
+	public function serialize( $format = null );
+
+	/**
+	 * Returns true if this Content object represents empty content.
+	 *
+	 * @since WD.1
+	 *
+	 * @return bool Whether this Content object is empty
+	 */
+	public function isEmpty();
+
+	/**
+	 * Returns whether the content is valid. This is intended for local validity
+	 * checks, not considering global consistency.
+	 *
+	 * Content needs to be valid before it can be saved.
+	 *
+	 * This default implementation always returns true.
+	 *
+	 * @since WD.1
+	 *
+	 * @return boolean
+	 */
+	public function isValid();
+
+	/**
+	 * Returns true if this Content objects is conceptually equivalent to the
+	 * given Content object.
+	 *
+	 * Contract:
+	 *
+	 * - Will return false if $that is null.
+	 * - Will return true if $that === $this.
+	 * - Will return false if $that->getModelName() != $this->getModel().
+	 * - Will return false if $that->getNativeData() is not equal to $this->getNativeData(),
+	 *   where the meaning of "equal" depends on the actual data model.
+	 *
+	 * Implementations should be careful to make equals() transitive and reflexive:
+	 *
+	 * - $a->equals( $b ) <=> $b->equals( $a )
+	 * - $a->equals( $b ) &&  $b->equals( $c ) ==> $a->equals( $c )
+	 *
+	 * @since WD.1
+	 *
+	 * @param $that Content The Content object to compare to
+	 * @return bool True if this Content object is equal to $that, false otherwise.
+	 */
+	public function equals( Content $that = null );
+
+	/**
+	 * Return a copy of this Content object. The following must be true for the
+	 * object returned:
+	 *
+	 * if $copy = $original->copy()
+	 *
+	 * - get_class($original) === get_class($copy)
+	 * - $original->getModel() === $copy->getModel()
+	 * - $original->equals( $copy )
+	 *
+	 * If and only if the Content object is immutable, the copy() method can and
+	 * should return $this. That is,  $copy === $original may be true, but only
+	 * for immutable content objects.
+	 *
+	 * @since WD.1
+	 *
+	 * @return Content. A copy of this object
+	 */
+	public function copy( );
+
+	/**
+	 * Returns true if this content is countable as a "real" wiki page, provided
+	 * that it's also in a countable location (e.g. a current revision in the
+	 * main namespace).
+	 *
+	 * @since WD.1
+	 *
+	 * @param $hasLinks Bool: If it is known whether this content contains
+	 *    links, provide this information here, to avoid redundant parsing to
+	 *    find out.
+	 * @return boolean
+	 */
+	public function isCountable( $hasLinks = null ) ;
+
+
+	/**
+	 * Parse the Content object and generate a ParserOutput from the result.
+	 * $result->getText() can be used to obtain the generated HTML. If no HTML
+	 * is needed, $generateHtml can be set to false; in that case,
+	 * $result->getText() may return null.
+	 *
+	 * @param $title Title The page title to use as a context for rendering
+	 * @param $revId null|int The revision being rendered (optional)
+	 * @param $options null|ParserOptions Any parser options
+	 * @param $generateHtml Boolean Whether to generate HTML (default: true). If false,
+	 *        the result of calling getText() on the ParserOutput object returned by
+	 *        this method is undefined.
+	 *
+	 * @since WD.1
+	 *
+	 * @return ParserOutput
+	 */
+	public function getParserOutput( Title $title,
+		$revId = null,
+		ParserOptions $options = null, $generateHtml = true );
+	# TODO: make RenderOutput and RenderOptions base classes
+
+	/**
+	 * Returns a list of DataUpdate objects for recording information about this
+	 * Content in some secondary data store. If the optional second argument,
+	 * $old, is given, the updates may model only the changes that need to be
+	 * made to replace information about the old content with information about
+	 * the new content.
+	 *
+	 * This default implementation calls
+	 * $this->getParserOutput( $content, $title, null, null, false ),
+	 * and then calls getSecondaryDataUpdates( $title, $recursive ) on the
+	 * resulting ParserOutput object.
+	 *
+	 * Subclasses may implement this to determine the necessary updates more
+	 * efficiently, or make use of information about the old content.
+	 *
+	 * @param $title Title The context for determining the necessary updates
+	 * @param $old Content|null An optional Content object representing the
+	 *    previous content, i.e. the content being replaced by this Content
+	 *    object.
+	 * @param $recursive boolean Whether to include recursive updates (default:
+	 *    false).
+	 * @param $parserOutput ParserOutput|null Optional ParserOutput object.
+	 *    Provide if you have one handy, to avoid re-parsing of the content.
+	 *
+	 * @return Array. A list of DataUpdate objects for putting information
+	 *    about this content object somewhere.
+	 *
+	 * @since WD.1
+	 */
+	public function getSecondaryDataUpdates( Title $title,
+		Content $old = null,
+		$recursive = true, ParserOutput $parserOutput = null
+	);
+
+	/**
+	 * Construct the redirect destination from this content and return an
+	 * array of Titles, or null if this content doesn't represent a redirect.
+	 * The last element in the array is the final destination after all redirects
+	 * have been resolved (up to $wgMaxRedirects times).
+	 *
+	 * @since WD.1
+	 *
+	 * @return Array of Titles, with the destination last
+	 */
+	public function getRedirectChain();
+
+	/**
+	 * Construct the redirect destination from this content and return a Title,
+	 * or null if this content doesn't represent a redirect.
+	 * This will only return the immediate redirect target, useful for
+	 * the redirect table and other checks that don't need full recursion.
+	 *
+	 * @since WD.1
+	 *
+	 * @return Title: The corresponding Title
+	 */
+	public function getRedirectTarget();
+
+	/**
+	 * Construct the redirect destination from this content and return the
+	 * Title, or null if this content doesn't represent a redirect.
+	 *
+	 * This will recurse down $wgMaxRedirects times or until a non-redirect
+	 * target is hit in order to provide (hopefully) the Title of the final
+	 * destination instead of another redirect.
+	 *
+	 * There is usually no need to override the default behaviour, subclasses that
+	 * want to implement redirects should override getRedirectTarget().
+	 * 
+	 * @since WD.1
+	 *
+	 * @return Title
+	 */
+	public function getUltimateRedirectTarget();
+
+	/**
+	 * Returns whether this Content represents a redirect.
+	 * Shorthand for getRedirectTarget() !== null.
+	 *
+	 * @since WD.1
+	 *
+	 * @return bool
+	 */
+	public function isRedirect();
+
+	/**
+	 * If this Content object is a redirect, this method updates the redirect target.
+	 * Otherwise, it does nothing.
+	 *
+	 * @since WD.1
+	 *
+	 * @param Title $target the new redirect target
+	 *
+	 * @return Content a new Content object with the updated redirect (or $this if this Content object isn't a redirect)
+	 */
+	public function updateRedirect( Title $target );
+
+	/**
+	 * Returns the section with the given ID.
+	 *
+	 * @since WD.1
+	 *
+	 * @param $sectionId string The section's ID, given as a numeric string.
+	 *    The ID "0" retrieves the section before the first heading, "1" the
+	 *    text between the first heading (included) and the second heading
+	 *    (excluded), etc.
+	 * @return Content|Boolean|null The section, or false if no such section
+	 *    exist, or null if sections are not supported.
+	 */
+	public function getSection( $sectionId );
+
+	/**
+	 * Replaces a section of the content and returns a Content object with the
+	 * section replaced.
+	 *
+	 * @since WD.1
+	 *
+	 * @param $section Empty/null/false or a section number (0, 1, 2, T1, T2...), or "new"
+	 * @param $with Content: new content of the section
+	 * @param $sectionTitle String: new section's subject, only if $section is 'new'
+	 * @return string Complete article text, or null if error
+	 */
+	public function replaceSection( $section, Content $with, $sectionTitle = ''  );
+
+	/**
+	 * Returns a Content object with pre-save transformations applied (or this
+	 * object if no transformations apply).
+	 *
+	 * @since WD.1
+	 *
+	 * @param $title Title
+	 * @param $user User
+	 * @param $popts null|ParserOptions
+	 * @return Content
+	 */
+	public function preSaveTransform( Title $title, User $user, ParserOptions $popts );
+
+	/**
+	 * Returns a new WikitextContent object with the given section heading
+	 * prepended, if supported. The default implementation just returns this
+	 * Content object unmodified, ignoring the section header.
+	 *
+	 * @since WD.1
+	 *
+	 * @param $header string
+	 * @return Content
+	 */
+	public function addSectionHeader( $header );
+
+	/**
+	 * Returns a Content object with preload transformations applied (or this
+	 * object if no transformations apply).
+	 *
+	 * @since WD.1
+	 *
+	 * @param $title Title
+	 * @param $popts null|ParserOptions
+	 * @return Content
+	 */
+	public function preloadTransform( Title $title, ParserOptions $popts );
+
+	/**
+	 * Prepare Content for saving. Called before Content is saved by WikiPage::doEditContent() and in
+	 * similar places.
+	 *
+	 * This may be used to check the content's consistency with global state. This function should
+	 * NOT write any information to the database.
+	 *
+	 * Note that this method will usually be called inside the same transaction bracket that will be used
+	 * to save the new revision.
+	 *
+	 * Note that this method is called before any update to the page table is performed. This means that
+	 * $page may not yet know a page ID.
+	 *
+	 * @param WikiPage $page The page to be saved.
+	 * @param int      $flags bitfield for use with EDIT_XXX constants, see WikiPage::doEditContent()
+	 * @param int      $baseRevId the ID of the current revision
+	 * @param User     $user
+	 *
+	 * @return Status A status object indicating whether the content was successfully prepared for saving.
+	 *                If the returned status indicates an error, a rollback will be performed and the
+	 *                transaction aborted.
+	 *
+	 * @see see WikiPage::doEditContent()
+	 */
+	public function prepareSave( WikiPage $page, $flags, $baseRevId, User $user );
+
+	/**
+	 * Returns a list of updates to perform when this content is deleted.
+	 * The necessary updates may be taken from the Content object, or depend on
+	 * the current state of the database.
+	 *
+	 * @since WD.1
+	 *
+	 * @param $page \WikiPage the deleted page
+	 * @param $parserOutput null|\ParserOutput optional parser output object
+	 *    for efficient access to meta-information about the content object.
+	 *    Provide if you have one handy.
+	 *
+	 * @return array A list of DataUpdate instances that will clean up the
+	 *    database after deletion.
+	 */
+	public function getDeletionUpdates( WikiPage $page,
+		ParserOutput $parserOutput = null );
+
+	/**
+	 * Returns true if this Content object matches the given magic word.
+	 *
+	 * @param MagicWord $word the magic word to match
+	 *
+	 * @return bool whether this Content object matches the given magic word.
+	 */
+	public function matchMagicWord( MagicWord $word );
+
+	# TODO: handle ImagePage and CategoryPage
+	# TODO: make sure we cover lucene search / wikisearch.
+	# TODO: make sure ReplaceTemplates still works
+	# FUTURE: nice&sane integration of GeSHi syntax highlighting
+	#   [11:59] <vvv> Hooks are ugly; make CodeHighlighter interface and a 
+	#   config to set the class which handles syntax highlighting
+	#   [12:00] <vvv> And default it to a DummyHighlighter
+
+	# TODO: make sure we cover the external editor interface (does anyone actually use that?!)
+
+	# TODO: tie into API to provide contentModel for Revisions
+	# TODO: tie into API to provide serialized version and contentFormat for Revisions
+	# TODO: tie into API edit interface
+	# FUTURE: make EditForm plugin for EditPage
+
+	# FUTURE: special type for redirects?!
+	# FUTURE: MultipartMultipart < WikipageContent (Main + Links + X)
+	# FUTURE: LinksContent < LanguageLinksContent, CategoriesContent
+}
+
 
 /**
  * A content object represents page content, e.g. the text to show on a page.
  * Content objects have no knowledge about how they relate to Wiki pages.
- * Content objects are imutable.
  *
+ * @since 1.WD
  */
-abstract class Content {
-    
-    public function __construct( $modelName = null ) {
-        $this->mModelName = $modelName;
-    }
-
-    public function getModelName() {
-        return $this->mModelName;
-    }
-
-    protected function checkModelName( $modelName ) {
-        if ( $modelName !== $this->mModelName ) {
-            throw new MWException( "Bad content model: expected " . $this->mModelName . " but got found " . $modelName );
-        }
-    }
-
-    public function getContentHandler() {
-        return ContentHandler::getForContent( $this );
-    }
-
-    public function getDefaultFormat() {
-        return $this->getContentHandler()->getDefaultFormat();
-    }
-
-    public function getSupportedFormats() {
-        return $this->getContentHandler()->getSupportedFormats();
-    }
-
-    public function isSupportedFormat( $format ) {
-        if ( !$format ) return true; # this means "use the default"
-
-        return $this->getContentHandler()->isSupportedFormat( $format );
-    }
-
-    protected function checkFormat( $format ) {
-        if ( !$this->isSupportedFormat( $format ) ) {
-            throw new MWException( "Format $format is not supported for content model " . $this->getModelName() );
-        }
-    }
-
-    public function serialize( $format = null ) {
-        return $this->getContentHandler()->serialize( $this, $format );
-    }
-
-    /**
-     * @return String a string representing the content in a way useful for building a full text search index.
-     *         If no useful representation exists, this method returns an empty string.
-     */
-    public abstract function getTextForSearchIndex( );
-
-    /**
-     * @return String the wikitext to include when another page includes this  content, or false if the content is not
-     *         includable in a wikitext page.
-     */
-    #TODO: allow native handling, bypassing wikitext representation, like for includable special pages.
-    public abstract function getWikitextForTransclusion( ); #FIXME: use in parser, etc!
-
-    /**
-     * Returns a textual representation of the content suitable for use in edit summaries and log messages.
-     *
-     * @param int $maxlength maximum length of the summary text
-     * @return String the summary text
-     */
-    public abstract function getTextForSummary( $maxlength = 250 );
-
-    /**
-     * Returns native represenation of the data. Interpretation depends on the data model used,
-     * as given by getDataModel().
-     *
-     * @return mixed the native representation of the content. Could be a string, a nested array
-     *         structure, an object, a binary blob... anything, really.
-     */
-    public abstract function getNativeData( ); #FIXME: review all calls carefully, caller must be aware of content model!
-
-    /**
-     * returns the content's nominal size in bogo-bytes.
-     *
-     * @return int
-     */
-    public abstract function getSize( );
-
-    public function isEmpty() {
-        return $this->getSize() == 0;
-    }
-
-    public function equals( Content $that ) {
-        if ( empty( $that ) ) return false;
-        if ( $that === $this ) return true;
-        if ( $that->getModelName() !== $this->getModelName() ) return false;
-
-        return $this->getNativeData() == $that->getNativeData();
-    }
-
-    /**
-     * Returns true if this content is countable as a "real" wiki page, provided
-     * that it's also in a countable location (e.g. a current revision in the main namespace).
-     *
-     * @param $hasLinks Bool: if it is known whether this content contains links, provide this information here,
-     *                        to avoid redundant parsing to find out.
-     */
-    public abstract function isCountable( $hasLinks = null ) ;
-
-    /**
-     * @param null|Title $title
-     * @param null $revId
-     * @param null|ParserOptions $options
-     * @param Boolean $generateHtml whether to generate Html (default: true). If false,
-     *        the result of calling getText() on the ParserOutput object returned by
-     *        this method is undefined.
-     *
-     * @return ParserOutput
-     */
-    public abstract function getParserOutput( Title $title = null, $revId = null, ParserOptions $options = NULL, $generateHtml = true );
-
-    /**
-     * Construct the redirect destination from this content and return an
-     * array of Titles, or null if this content doesn't represent a redirect.
-     * The last element in the array is the final destination after all redirects
-     * have been resolved (up to $wgMaxRedirects times).
-     *
-     * @return Array of Titles, with the destination last
-     */
-    public function getRedirectChain() {
-        return null;
-    }
-
-    /**
-     * Construct the redirect destination from this content and return an
-     * array of Titles, or null if this content doesn't represent a redirect.
-     * This will only return the immediate redirect target, useful for
-     * the redirect table and other checks that don't need full recursion.
-     *
-     * @return Title: The corresponding Title
-     */
-    public function getRedirectTarget() {
-        return null;
-    }
-
-    /**
-     * Construct the redirect destination from this content and return the
-     * Title, or null if this content doesn't represent a redirect.
-     * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
-     * in order to provide (hopefully) the Title of the final destination instead of another redirect.
-     *
-     * @return Title
-     */
-    public function getUltimateRedirectTarget() {
-        return null;
-    }
-
-    public function isRedirect() {
-        return $this->getRedirectTarget() != null;
-    }
-
-    /**
-     * Returns the section with the given id.
-     *
-     * The default implementation returns null.
-     *
-     * @param String $sectionId the section's id
-     * @return Content|Boolean|null the section, or false if no such section exist, or null if sections are not supported
-     */
-    public function getSection( $sectionId ) {
-        return null;
-    }
-
-    /**
-     * Replaces a section of the content and returns a Content object with the section replaced.
-     *
-     * @param $section empty/null/false or a section number (0, 1, 2, T1, T2...), or "new"
-     * @param $with Content: new content of the section
-     * @param $sectionTitle String: new section's subject, only if $section is 'new'
-     * @return string Complete article text, or null if error
-     */
-    public function replaceSection( $section, Content $with, $sectionTitle = ''  ) {
-        return $this;
-    }
-
-    /**
-     * Returns a Content object with pre-save transformations applied (or this object if no transformations apply).
-     *
-     * @param Title $title
-     * @param User $user
-     * @param null|ParserOptions $popts
-     * @return Content
-     */
-    public function preSaveTransform( Title $title, User $user, ParserOptions $popts = null ) {
-        return $this;
-    }
-
-    /**
-     * Returns a new WikitextContent object with the given section heading prepended, if supported.
-     * The default implementation just returns this Content object unmodified, ignoring the section header.
-     *
-     * @param $header String
-     * @return Content
-     */
-    public function addSectionHeader( $header ) {
-        return $this;
-    }
-
-    /**
-     * Returns a Content object with preload transformations applied (or this object if no transformations apply).
-     *
-     * @param Title $title
-     * @param null|ParserOptions $popts
-     * @return Content
-     */
-    public function preloadTransform( Title $title, ParserOptions $popts = null ) {
-        return $this;
-    }
-
-    # TODO: minimize special cases for CSS/JS; how to handle extra message for JS/CSS previews??
-    # TODO: handle ImagePage and CategoryPage
-    # TODO: hook into dump generation to serialize and record model and format!
-
-    # TODO: make sure we cover lucene search / wikisearch.
-    # TODO: make sure ReplaceTemplates still works
-    # TODO: nice&sane integration of GeSHi syntax highlighting
-    #   [11:59] <vvv> Hooks are ugly; make CodeHighlighter interface and a config to set the class which handles syntax highlighting
-    #   [12:00] <vvv> And default it to a DummyHighlighter
-
-    # TODO: make sure we cover the external editor interface (does anyone actually use that?!)
-
-    # TODO: tie into API to provide contentModel for Revisions
-    # TODO: tie into API to provide serialized version and contentFormat for Revisions
-    # TODO: tie into API edit interface
-    # TODO: make EditForm plugin for EditPage
-
-    # XXX: isCacheable( ) # can/should we do this here?
+abstract class AbstractContent implements Content {
+
+	/**
+	 * Name of the content model this Content object represents.
+	 * Use with CONTENT_MODEL_XXX constants
+	 *
+	 * @var string $model_id
+	 */
+	protected $model_id;
+
+	/**
+	 * @param String $model_id
+	 */
+	public function __construct( $model_id = null ) {
+		$this->model_id = $model_id;
+	}
+
+	/**
+	 * @see Content::getModel()
+	 */
+	public function getModel() {
+		return $this->model_id;
+	}
+
+	/**
+	 * Throws an MWException if $model_id is not the id of the content model
+	 * supported by this Content object.
+	 *
+	 * @param $model_id int the model to check
+	 *
+	 * @throws MWException
+	 */
+	protected function checkModelID( $model_id ) {
+		if ( $model_id !== $this->model_id ) {
+			throw new MWException( "Bad content model: " .
+				"expected {$this->model_id}  " .
+				"but got $model_id." );
+		}
+	}
+
+	/**
+	 * @see Content::getContentHandler()
+	 */
+	public function getContentHandler() {
+		return ContentHandler::getForContent( $this );
+	}
+
+	/**
+	 * @see Content::getDefaultFormat()
+	 */
+	public function getDefaultFormat() {
+		return $this->getContentHandler()->getDefaultFormat();
+	}
+
+	/**
+	 * @see Content::getSupportedFormats()
+	 */
+	public function getSupportedFormats() {
+		return $this->getContentHandler()->getSupportedFormats();
+	}
+
+	/**
+	 * @see Content::isSupportedFormat()
+	 */
+	public function isSupportedFormat( $format ) {
+		if ( !$format ) {
+			return true; // this means "use the default"
+		}
+
+		return $this->getContentHandler()->isSupportedFormat( $format );
+	}
+
+	/**
+	 * Throws an MWException if $this->isSupportedFormat( $format ) doesn't
+	 * return true.
+	 *
+	 * @param $format
+	 * @throws MWException
+	 */
+	protected function checkFormat( $format ) {
+		if ( !$this->isSupportedFormat( $format ) ) {
+			throw new MWException( "Format $format is not supported for content model " . 
+				$this->getModel() );
+		}
+	}
+
+	/**
+	 * @see Content::serialize
+	 */
+	public function serialize( $format = null ) {
+		return $this->getContentHandler()->serializeContent( $this, $format );
+	}
+
+	/**
+	 * @see Content::isEmpty()
+	 */
+	public function isEmpty() {
+		return $this->getSize() == 0;
+	}
+
+	/**
+	 * @see Content::isValid()
+	 */
+	public function isValid() {
+		return true;
+	}
+
+	/**
+	 * @see Content::equals()
+	 */
+	public function equals( Content $that = null ) {
+		if ( is_null( $that ) ) {
+			return false;
+		}
+
+		if ( $that === $this ) {
+			return true;
+		}
+
+		if ( $that->getModel() !== $this->getModel() ) {
+			return false;
+		}
+
+		return $this->getNativeData() === $that->getNativeData();
+	}
+
+
+	/**
+	 * Returns a list of DataUpdate objects for recording information about this
+	 * Content in some secondary data store.
+	 *
+	 * This default implementation calls
+	 * $this->getParserOutput( $content, $title, null, null, false ),
+	 * and then calls getSecondaryDataUpdates( $title, $recursive ) on the
+	 * resulting ParserOutput object.
+	 *
+	 * Subclasses may override this to determine the secondary data updates more
+	 * efficiently, preferrably without the need to generate a parser output object.
+	 *
+	 * @see Content::getSecondaryDataUpdates()
+	 *
+	 * @param $title Title The context for determining the necessary updates
+	 * @param $old Content|null An optional Content object representing the
+	 *    previous content, i.e. the content being replaced by this Content
+	 *    object.
+	 * @param $recursive boolean Whether to include recursive updates (default:
+	 *    false).
+	 * @param $parserOutput ParserOutput|null Optional ParserOutput object.
+	 *    Provide if you have one handy, to avoid re-parsing of the content.
+	 *
+	 * @return Array. A list of DataUpdate objects for putting information
+	 *    about this content object somewhere.
+	 *
+	 * @since WD.1
+	 */
+	public function getSecondaryDataUpdates( Title $title,
+		Content $old = null,
+		$recursive = true, ParserOutput $parserOutput = null
+	) {
+		if ( !$parserOutput ) {
+			$parserOutput = $this->getParserOutput( $title, null, null, false );
+		}
+
+		return $parserOutput->getSecondaryDataUpdates( $title, $recursive );
+	}
+
+
+	/**
+	 * @see Content::getRedirectChain()
+	 */
+	public function getRedirectChain() {
+		global $wgMaxRedirects;
+		$title = $this->getRedirectTarget();
+		if ( is_null( $title ) ) {
+			return null;
+		}
+		// recursive check to follow double redirects
+		$recurse = $wgMaxRedirects;
+		$titles = array( $title );
+		while ( --$recurse > 0 ) {
+			if ( $title->isRedirect() ) {
+				$page = WikiPage::factory( $title );
+				$newtitle = $page->getRedirectTarget();
+			} else {
+				break;
+			}
+			// Redirects to some special pages are not permitted
+			if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
+				// The new title passes the checks, so make that our current
+				// title so that further recursion can be checked
+				$title = $newtitle;
+				$titles[] = $newtitle;
+			} else {
+				break;
+			}
+		}
+		return $titles;
+	}
+
+	/**
+	 * @see Content::getRedirectTarget()
+	 */
+	public function getRedirectTarget() {
+		return null;
+	}
+
+	/**
+	 * @see Content::getUltimateRedirectTarget()
+	 * @note: migrated here from Title::newFromRedirectRecurse
+	 */
+	public function getUltimateRedirectTarget() {
+		$titles = $this->getRedirectChain();
+		return $titles ? array_pop( $titles ) : null;
+	}
+
+	/**
+	 * @see Content::isRedirect()
+	 *
+	 * @since WD.1
+	 *
+	 * @return bool
+	 */
+	public function isRedirect() {
+		return $this->getRedirectTarget() !== null;
+	}
+
+	/**
+	 * @see Content::updateRedirect()
+	 *
+	 * This default implementation always returns $this.
+	 *
+	 * @since WD.1
+	 *
+	 * @return Content $this
+	 */
+	public function updateRedirect( Title $target ) {
+		return $this;
+	}
+
+	/**
+	 * @see Content::getSection()
+	 */
+	public function getSection( $sectionId ) {
+		return null;
+	}
+
+	/**
+	 * @see Content::replaceSection()
+	 */
+	public function replaceSection( $section, Content $with, $sectionTitle = ''  ) {
+		return null;
+	}
+
+	/**
+	 * @see Content::preSaveTransform()
+	 */
+	public function preSaveTransform( Title $title, User $user, ParserOptions $popts ) {
+		return $this;
+	}
+
+	/**
+	 * @see Content::addSectionHeader()
+	 */
+	public function addSectionHeader( $header ) {
+		return $this;
+	}
+
+	/**
+	 * @see Content::preloadTransform()
+	 */
+	public function preloadTransform( Title $title, ParserOptions $popts ) {
+		return $this;
+	}
+
+	/**
+	 * @see  Content::prepareSave()
+	 */
+	public function prepareSave( WikiPage $page, $flags, $baseRevId, User $user ) {
+		if ( $this->isValid() ) {
+			return Status::newGood();
+		} else {
+			return Status::newFatal( "invalid-content-data" );
+		}
+	}
+
+	/**
+	 * @see  Content::getDeletionUpdates()
+	 *
+	 * @since WD.1
+	 *
+	 * @param $page \WikiPage the deleted page
+	 * @param $parserOutput null|\ParserOutput optional parser output object
+	 *    for efficient access to meta-information about the content object.
+	 *    Provide if you have one handy.
+	 *
+	 * @return array A list of DataUpdate instances that will clean up the
+	 *    database after deletion.
+	 */
+	public function getDeletionUpdates( WikiPage $page,
+		ParserOutput $parserOutput = null )
+	{
+		return array(
+			new LinksDeletionUpdate( $page ),
+		);
+	}
+
+	/**
+	 * @see  Content::matchMagicWord()
+	 *
+	 * This default implementation always returns false. Subclasses may override this to supply matching logic.
+	 *
+	 * @param MagicWord $word
+	 *
+	 * @return bool
+	 */
+	public function matchMagicWord( MagicWord $word ) {
+		return false;
+	}
 }
 
 /**
- * Content object implementation for representing flat text. The
+ * Content object implementation for representing flat text.
+ *
+ * TextContent instances are immutable
+ *
+ * @since WD.1
  */
-abstract class TextContent extends Content {
-    public function __construct( $text, $modelName = null ) {
-        parent::__construct($modelName);
-
-        $this->mText = $text;
-    }
-
-    public function getTextForSummary( $maxlength = 250 ) {
-        global $wgContLang;
-
-        $text = $this->getNativeData();
-
-        $truncatedtext = $wgContLang->truncate(
-            preg_replace( "/[\n\r]/", ' ', $text ),
-            max( 0, $maxlength ) );
-
-        return $truncatedtext;
-    }
-
-    /**
-     * returns the content's nominal size in bogo-bytes.
-     */
-    public function getSize( ) { #FIXME: use! replace strlen in WikiPage.
-        $text = $this->getNativeData( );
-        return strlen( $text );
-    }
-
-    /**
-     * Returns true if this content is not a redirect, and $wgArticleCountMethod is "any".
-     *
-     * @param $hasLinks Bool: if it is known whether this content contains links, provide this information here,
-     *                        to avoid redundant parsing to find out.
-     */
-    public function isCountable( $hasLinks = null ) {
-        global $wgArticleCountMethod;
-
-        if ( $this->isRedirect( ) ) {
-            return false;
-        }
-
-        if (  $wgArticleCountMethod === 'any' ) {
-            return true;
-        }
-
-        return false;
-    }
-
-    /**
-     * Returns the text represented by this Content object, as a string.
-     *
-     * @return String the raw text
-     */
-    public function getNativeData( ) {
-        $text = $this->mText;
-        return $text;
-    }
-
-    /**
-     * Returns the text represented by this Content object, as a string.
-     *
-     * @return String the raw text
-     */
-    public function getTextForSearchIndex( ) { #FIXME: use!
-        return $this->getNativeData();
-    }
-
-    /**
-     * Returns the text represented by this Content object, as a string.
-     *
-     * @return String the raw text
-     */
-    public function getWikitextForTransclusion( ) { #FIXME: use!
-        return $this->getNativeData();
-    }
-
-    /**
-     * Returns a generic ParserOutput object, wrapping the HTML returned by getHtml().
-     *
-     * @return ParserOutput representing the HTML form of the text
-     */
-    public function getParserOutput( Title $title = null, $revId = null, ParserOptions $options = null, $generateHtml = true ) {
-        # generic implementation, relying on $this->getHtml()
-
-        if ( $generateHtml ) $html = $this->getHtml( $options );
-        else $html = '';
-
-        $po = new ParserOutput( $html );
-
-        return $po;
-    }
-
-    protected abstract function getHtml( );
-
+abstract class TextContent extends AbstractContent {
+
+	public function __construct( $text, $model_id = null ) {
+		parent::__construct( $model_id );
+
+		$this->mText = $text;
+	}
+
+	public function copy() {
+		return $this; # NOTE: this is ok since TextContent are immutable.
+	}
+
+	public function getTextForSummary( $maxlength = 250 ) {
+		global $wgContLang;
+
+		$text = $this->getNativeData();
+
+		$truncatedtext = $wgContLang->truncate(
+			preg_replace( "/[\n\r]/", ' ', $text ),
+			max( 0, $maxlength ) );
+
+		return $truncatedtext;
+	}
+
+	/**
+	 * returns the text's size in bytes.
+	 *
+	 * @return int The size
+	 */
+	public function getSize( ) {
+		$text = $this->getNativeData( );
+		return strlen( $text );
+	}
+
+	/**
+	 * Returns true if this content is not a redirect, and $wgArticleCountMethod
+	 * is "any".
+	 *
+	 * @param $hasLinks Bool: if it is known whether this content contains links,
+	 * provide this information here, to avoid redundant parsing to find out.
+	 *
+	 * @return bool True if the content is countable
+	 */
+	public function isCountable( $hasLinks = null ) {
+		global $wgArticleCountMethod;
+
+		if ( $this->isRedirect( ) ) {
+			return false;
+		}
+
+		if (  $wgArticleCountMethod === 'any' ) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Returns the text represented by this Content object, as a string.
+	 *
+	 * @param   the raw text
+	 */
+	public function getNativeData( ) {
+		$text = $this->mText;
+		return $text;
+	}
+
+	/**
+	 * Returns the text represented by this Content object, as a string.
+	 *
+	 * @param   the raw text
+	 */
+	public function getTextForSearchIndex( ) {
+		return $this->getNativeData();
+	}
+
+	/**
+	 * Returns the text represented by this Content object, as a string.
+	 *
+	 * @param   the raw text
+	 */
+	public function getWikitextForTransclusion( ) {
+		return $this->getNativeData();
+	}
+
+	/**
+	 * Diff this content object with another content object..
+	 *
+	 * @since WD.diff
+	 *
+	 * @param $that Content the other content object to compare this content object to
+	 * @param $lang Language the language object to use for text segmentation.
+	 *    If not given, $wgContentLang is used.
+	 *
+	 * @return DiffResult a diff representing the changes that would have to be
+	 *    made to this content object to make it equal to $that.
+	 */
+	public function diff( Content $that, Language $lang = null ) {
+		global $wgContLang;
+
+		$this->checkModelID( $that->getModel() );
+
+		# @todo: could implement this in DifferenceEngine and just delegate here?
+
+		if ( !$lang ) $lang = $wgContLang;
+
+		$otext = $this->getNativeData();
+		$ntext = $this->getNativeData();
+
+		# Note: Use native PHP diff, external engines don't give us abstract output
+		$ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
+		$nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
+
+		$diff = new Diff( $ota, $nta );
+		return $diff;
+	}
+
+
+	/**
+	 * Returns a generic ParserOutput object, wrapping the HTML returned by
+	 * getHtml().
+	 *
+	 * @param $title Title Context title for parsing
+	 * @param $revId int|null Revision ID (for {{REVISIONID}})
+	 * @param $options ParserOptions|null Parser options
+	 * @param $generateHtml bool Whether or not to generate HTML
+	 *
+	 * @return ParserOutput representing the HTML form of the text
+	 */
+	public function getParserOutput( Title $title,
+		$revId = null,
+		ParserOptions $options = null, $generateHtml = true
+	) {
+		# Generic implementation, relying on $this->getHtml()
+
+		if ( $generateHtml ) {
+			$html = $this->getHtml();
+		} else {
+			$html = '';
+		}
+
+		$po = new ParserOutput( $html );
+		return $po;
+	}
+
+	/**
+	 * Generates an HTML version of the content, for display. Used by
+	 * getParserOutput() to construct a ParserOutput object.
+	 *
+	 * This default implementation just calls getHighlightHtml(). Content
+	 * models that have another mapping to HTML (as is the case for markup
+	 * languages like wikitext) should override this method to generate the
+	 * appropriate HTML.
+	 *
+	 * @return string An HTML representation of the content
+	 */
+	protected function getHtml() {
+		return $this->getHighlightHtml();
+	}
+
+	/**
+	 * Generates a syntax-highlighted version of the content, as HTML.
+	 * Used by the default implementation of getHtml().
+	 *
+	 * @return string an HTML representation of the content's markup
+	 */
+	protected function getHighlightHtml( ) {
+		# TODO: make Highlighter interface, use highlighter here, if available
+		return htmlspecialchars( $this->getNativeData() );
+	}
 }
 
+/**
+ * @since WD.1
+ */
 class WikitextContent extends TextContent {
-    public function __construct( $text ) {
-        parent::__construct($text, CONTENT_MODEL_WIKITEXT);
-
-        $this->mDefaultParserOptions = null; #TODO: use per-class static member?!
-    }
-
-    protected function getHtml( ) {
-        throw new MWException( "getHtml() not implemented for wikitext. Use getParserOutput()->getText()." );
-    }
-
-    public function getDefaultParserOptions() {
-        global $wgUser, $wgContLang;
-
-        if ( !$this->mDefaultParserOptions ) { #TODO: use per-class static member?!
-            $this->mDefaultParserOptions = ParserOptions::newFromUserAndLang( $wgUser, $wgContLang );
-        }
-
-        return $this->mDefaultParserOptions;
-    }
-
-    /**
-     * Returns a ParserOutput object reesulting from parsing the content's text using $wgParser
-     *
-     * @return ParserOutput representing the HTML form of the text
-     */
-    public function getParserOutput( Title $title = null, $revId = null, ParserOptions $options = null, $generateHtml = true ) {
-        global $wgParser;
-
-        if ( !$options ) {
-            $options = $this->getDefaultParserOptions();
-        }
-
-        $po = $wgParser->parse( $this->mText, $title, $options, true, true, $revId );
-
-        return $po;
-    }
-
-    /**
-     * Returns the section with the given id.
-     *
-     * @param String $sectionId the section's id
-     * @return Content|false|null the section, or false if no such section exist, or null if sections are not supported
-     */
-    public function getSection( $section ) {
-        global $wgParser;
-
-        $text = $this->getNativeData();
-        $sect = $wgParser->getSection( $text, $section, false );
-
-        return  new WikitextContent( $sect );
-    }
-
-    /**
-     * Replaces a section in the wikitext
-     *
-     * @param $section empty/null/false or a section number (0, 1, 2, T1, T2...), or "new"
-     * @param $with Content: new content of the section
-     * @param $sectionTitle String: new section's subject, only if $section is 'new'
-     * @return string Complete article text, or null if error
-     */
-    public function replaceSection( $section, Content $with, $sectionTitle = '' ) {
-        global $wgParser;
-
-        wfProfileIn( __METHOD__ );
-
-        $myModelName = $this->getModelName();
-        $sectionModelName = $with->getModelName();
-
-        if ( $sectionModelName != $myModelName  ) {
-            throw new MWException( "Incompatible content model for section: document uses $myModelName, section uses $sectionModelName." );
-        }
-
-        $oldtext = $this->getNativeData();
-        $text = $with->getNativeData();
-
-        if ( $section == 'new' ) {
-            # Inserting a new section
-            $subject = $sectionTitle ? wfMsgForContent( 'newsectionheaderdefaultlevel', $sectionTitle ) . "\n\n" : '';
-            if ( wfRunHooks( 'PlaceNewSection', array( $this, $oldtext, $subject, &$text ) ) ) {
-                $text = strlen( trim( $oldtext ) ) > 0
-                    ? "{$oldtext}\n\n{$subject}{$text}"
-                    : "{$subject}{$text}";
-            }
-        } else {
-            # Replacing an existing section; roll out the big guns
-            global $wgParser;
-
-            $text = $wgParser->replaceSection( $oldtext, $section, $text );
-        }
-
-        $newContent = new WikitextContent( $text );
-
-        wfProfileOut( __METHOD__ );
-        return $newContent;
-    }
-
-    /**
-     * Returns a new WikitextContent object with the given section heading prepended.
-     *
-     * @param $header String
-     * @return Content
-     */
-    public function addSectionHeader( $header ) {
-        $text = wfMsgForContent( 'newsectionheaderdefaultlevel', $this->sectiontitle ) . "\n\n" . $this->getNativeData();
-
-        return new WikitextContent( $text );
-    }
-
-    /**
-     * Returns a Content object with pre-save transformations applied (or this object if no transformations apply).
-     *
-     * @param Title $title
-     * @param User $user
-     * @param null|ParserOptions $popts
-     * @return Content
-     */
-    public function preSaveTransform( Title $title, User $user, ParserOptions $popts = null ) {
-        global $wgParser;
-
-        if ( $popts == null ) $popts = $this->getDefaultParserOptions();
-
-        $text = $this->getNativeData();
-        $pst = $wgParser->preSaveTransform( $text, $title, $user, $popts );
-
-        return new WikitextContent( $pst );
-    }
-
-    /**
-     * Returns a Content object with preload transformations applied (or this object if no transformations apply).
-     *
-     * @param Title $title
-     * @param null|ParserOptions $popts
-     * @return Content
-     */
-    public function preloadTransform( Title $title, ParserOptions $popts = null ) {
-        global $wgParser;
-
-        if ( $popts == null ) $popts = $this->getDefaultParserOptions();
-
-        $text = $this->getNativeData();
-        $plt = $wgParser->getPreloadText( $text, $title, $popts );
-
-        return new WikitextContent( $plt );
-    }
-
-    public function getRedirectChain() {
-        $text = $this->getNativeData();
-        return Title::newFromRedirectArray( $text );
-    }
-
-    public function getRedirectTarget() {
-        $text = $this->getNativeData();
-        return Title::newFromRedirect( $text );
-    }
-
-    public function getUltimateRedirectTarget() {
-        $text = $this->getNativeData();
-        return Title::newFromRedirectRecurse( $text );
-    }
-
-    /**
-     * Returns true if this content is not a redirect, and this content's text is countable according to
-     * the criteria defiend by $wgArticleCountMethod.
-     *
-     * @param $hasLinks Bool: if it is known whether this content contains links, provide this information here,
-     *                        to avoid redundant parsing to find out.
-     */
-    public function isCountable( $hasLinks = null ) {
-        global $wgArticleCountMethod;
-
-        if ( $this->isRedirect( ) ) {
-            return false;
-        }
-
-        $text = $this->getNativeData();
-
-        switch ( $wgArticleCountMethod ) {
-            case 'any':
-                return true;
-            case 'comma':
-                if ( $text === false ) {
-                    $text = $this->getRawText();
-                }
-                return strpos( $text,  ',' ) !== false;
-            case 'link':
-                if ( $hasLinks === null ) { # not know, find out
-                    $po = $this->getParserOutput();
-                    $links = $po->getLinks();
-                    $hasLinks = !empty( $links );
-                }
-
-                return $hasLinks;
-        }
-    }
-
-    public function getTextForSummary( $maxlength = 250 ) {
-        $truncatedtext = parent::getTextForSummary( $maxlength );
-
-        #clean up unfinished links
-        #XXX: make this optional? wasn't there in autosummary, but required for deletion summary.
-        $truncatedtext = preg_replace( '/\[\[([^\]]*)\]?$/', '$1', $truncatedtext );
-
-        return $truncatedtext;
-    }
 
+	public function __construct( $text ) {
+		parent::__construct( $text, CONTENT_MODEL_WIKITEXT );
+	}
+
+	/**
+	 * @see Content::getSection()
+	 */
+	public function getSection( $section ) {
+		global $wgParser;
+
+		$text = $this->getNativeData();
+		$sect = $wgParser->getSection( $text, $section, false );
+
+		return  new WikitextContent( $sect );
+	}
+
+	/**
+	 * @see Content::replaceSection()
+	 */
+	public function replaceSection( $section, Content $with, $sectionTitle = '' ) {
+		wfProfileIn( __METHOD__ );
+
+		$myModelId = $this->getModel();
+		$sectionModelId = $with->getModel();
+
+		if ( $sectionModelId != $myModelId  ) {
+			throw new MWException( "Incompatible content model for section: " .
+				"document uses $myModelId but " .
+				"section uses $sectionModelId." );
+		}
+
+		$oldtext = $this->getNativeData();
+		$text = $with->getNativeData();
+
+		if ( $section === '' ) {
+			return $with; # XXX: copy first?
+		} if ( $section == 'new' ) {
+			# Inserting a new section
+			$subject = $sectionTitle ? wfMessage( 'newsectionheaderdefaultlevel' )
+				->rawParams( $sectionTitle )->inContentLanguage()->text() . "\n\n" : '';
+			if ( wfRunHooks( 'PlaceNewSection', array( $this, $oldtext, $subject, &$text ) ) ) {
+				$text = strlen( trim( $oldtext ) ) > 0
+					? "{$oldtext}\n\n{$subject}{$text}"
+					: "{$subject}{$text}";
+			}
+		} else {
+			# Replacing an existing section; roll out the big guns
+			global $wgParser;
+
+			$text = $wgParser->replaceSection( $oldtext, $section, $text );
+		}
+
+		$newContent = new WikitextContent( $text );
+
+		wfProfileOut( __METHOD__ );
+		return $newContent;
+	}
+
+	/**
+	 * Returns a new WikitextContent object with the given section heading
+	 * prepended.
+	 *
+	 * @param $header string
+	 * @return Content
+	 */
+	public function addSectionHeader( $header ) {
+		$text = wfMessage( 'newsectionheaderdefaultlevel' )
+				->inContentLanguage()->params( $header )->text();
+		$text .= "\n\n";
+		$text .= $this->getNativeData();
+
+		return new WikitextContent( $text );
+	}
+
+	/**
+	 * Returns a Content object with pre-save transformations applied using
+	 * Parser::preSaveTransform().
+	 *
+	 * @param $title Title
+	 * @param $user User
+	 * @param $popts ParserOptions
+	 * @return Content
+	 */
+	public function preSaveTransform( Title $title, User $user, ParserOptions $popts ) {
+		global $wgParser;
+
+		$text = $this->getNativeData();
+		$pst = $wgParser->preSaveTransform( $text, $title, $user, $popts );
+
+		return new WikitextContent( $pst );
+	}
+
+	/**
+	 * Returns a Content object with preload transformations applied (or this
+	 * object if no transformations apply).
+	 *
+	 * @param $title Title
+	 * @param $popts ParserOptions
+	 * @return Content
+	 */
+	public function preloadTransform( Title $title, ParserOptions $popts ) {
+		global $wgParser;
+
+		$text = $this->getNativeData();
+		$plt = $wgParser->getPreloadText( $text, $title, $popts );
+
+		return new WikitextContent( $plt );
+	}
+
+	/**
+	 * Implement redirect extraction for wikitext.
+	 *
+	 * @return null|Title
+	 *
+	 * @note: migrated here from Title::newFromRedirectInternal()
+	 *
+	 * @see Content::getRedirectTarget
+	 * @see AbstractContent::getRedirectTarget
+	 */
+	public function getRedirectTarget() {
+		global $wgMaxRedirects;
+		if ( $wgMaxRedirects < 1 ) {
+			// redirects are disabled, so quit early
+			return null;
+		}
+		$redir = MagicWord::get( 'redirect' );
+		$text = trim( $this->getNativeData() );
+		if ( $redir->matchStartAndRemove( $text ) ) {
+			// Extract the first link and see if it's usable
+			// Ensure that it really does come directly after #REDIRECT
+			// Some older redirects included a colon, so don't freak about that!
+			$m = array();
+			if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
+				// Strip preceding colon used to "escape" categories, etc.
+				// and URL-decode links
+				if ( strpos( $m[1], '%' ) !== false ) {
+					// Match behavior of inline link parsing here;
+					$m[1] = rawurldecode( ltrim( $m[1], ':' ) );
+				}
+				$title = Title::newFromText( $m[1] );
+				// If the title is a redirect to bad special pages or is invalid, return null
+				if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
+					return null;
+				}
+				return $title;
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * @see   Content::updateRedirect()
+	 *
+	 * This implementation replaces the first link on the page with the given new target
+	 * if this Content object is a redirect. Otherwise, this method returns $this.
+	 *
+	 * @since WD.1
+	 *
+	 * @param Title $target
+	 *
+	 * @return Content a new Content object with the updated redirect (or $this if this Content object isn't a redirect)
+	 */
+	public function updateRedirect( Title $target ) {
+		if ( !$this->isRedirect() ) {
+			return $this;
+		}
+
+		# Fix the text
+		# Remember that redirect pages can have categories, templates, etc.,
+		# so the regex has to be fairly general
+		$newText = preg_replace( '/ \[ \[  [^\]]*  \] \] /x',
+			'[[' . $target->getFullText() . ']]',
+			$this->getNativeData(), 1 );
+
+		return new WikitextContent( $newText );
+	}
+
+	/**
+	 * Returns true if this content is not a redirect, and this content's text
+	 * is countable according to the criteria defined by $wgArticleCountMethod.
+	 *
+	 * @param $hasLinks Bool  if it is known whether this content contains
+	 *    links, provide this information here, to avoid redundant parsing to
+	 *    find out.
+	 * @param $title null|\Title
+	 *
+	 * @internal param \IContextSource $context context for parsing if necessary
+	 *
+	 * @return bool True if the content is countable
+	 */
+	public function isCountable( $hasLinks = null, Title $title = null ) {
+		global $wgArticleCountMethod;
+
+		if ( $this->isRedirect( ) ) {
+			return false;
+		}
+
+		$text = $this->getNativeData();
+
+		switch ( $wgArticleCountMethod ) {
+			case 'any':
+				return true;
+			case 'comma':
+				return strpos( $text,  ',' ) !== false;
+			case 'link':
+				if ( $hasLinks === null ) { # not known, find out
+					if ( !$title ) {
+						$context = RequestContext::getMain();
+						$title = $context->getTitle();
+					}
+
+					$po = $this->getParserOutput( $title, null, null, false );
+					$links = $po->getLinks();
+					$hasLinks = !empty( $links );
+				}
+
+				return $hasLinks;
+		}
+
+		return false;
+	}
+
+	public function getTextForSummary( $maxlength = 250 ) {
+		$truncatedtext = parent::getTextForSummary( $maxlength );
+
+		# clean up unfinished links
+		# XXX: make this optional? wasn't there in autosummary, but required for
+		# deletion summary.
+		$truncatedtext = preg_replace( '/\[\[([^\]]*)\]?$/', '$1', $truncatedtext );
+
+		return $truncatedtext;
+	}
+
+
+	/**
+	 * Returns a ParserOutput object resulting from parsing the content's text
+	 * using $wgParser.
+	 *
+	 * @since    WD.1
+	 *
+	 * @param $content Content the content to render
+	 * @param $title \Title
+	 * @param $revId null
+	 * @param $options null|ParserOptions
+	 * @param $generateHtml bool
+	 *
+	 * @internal param \IContextSource|null $context
+	 * @return ParserOutput representing the HTML form of the text
+	 */
+	public function getParserOutput( Title $title,
+		$revId = null,
+		ParserOptions $options = null, $generateHtml = true
+	) {
+		global $wgParser;
+
+		if ( !$options ) {
+			$options = new ParserOptions();
+		}
+
+		$po = $wgParser->parse( $this->getNativeData(), $title, $options, true, true, $revId );
+		return $po;
+	}
+
+	protected function getHtml() {
+		throw new MWException(
+			"getHtml() not implemented for wikitext. "
+				. "Use getParserOutput()->getText()."
+		);
+	}
+
+	/**
+	 * @see  Content::matchMagicWord()
+	 *
+	 * This implementation calls $word->match() on the this TextContent object's text.
+	 *
+	 * @param MagicWord $word
+	 *
+	 * @return bool whether this Content object matches the given magic word.
+	 */
+	public function matchMagicWord( MagicWord $word ) {
+		return $word->match( $this->getNativeData() );
+	}
 }
 
-class MessageContent extends TextContent {
-    public function __construct( $msg_key, $params = null, $options = null ) {
-        parent::__construct(null, CONTENT_MODEL_WIKITEXT); #XXX: messages may be wikitext, html or plain text! and maybe even something else entirely.
-
-        $this->mMessageKey = $msg_key;
-
-        $this->mParameters = $params;
-
-        if ( !$options ) $options = array();
-        $this->mOptions = $options;
-
-        $this->mHtmlOptions = null;
-    }
-
-    /**
-     * Returns the message as rendered HTML, using the options supplied to the constructor plus "parse".
-     */
-    protected function getHtml(  ) {
-        $opt = array_merge( $this->mOptions, array('parse') );
-
-        return wfMsgExt( $this->mMessageKey, $this->mParameters, $opt );
-    }
-
-
-    /**
-     * Returns the message as raw text, using the options supplied to the constructor minus "parse" and "parseinline".
-     */
-    public function getNativeData( ) {
-        $opt = array_diff( $this->mOptions, array('parse', 'parseinline') );
-
-        return wfMsgExt( $this->mMessageKey, $this->mParameters, $opt );
-    }
-
+/**
+ * Wrapper allowing us to handle a system message as a Content object. Note that this is generally *not* used
+ * to represent content from the MediaWiki namespace, and that there is no MessageContentHandler. MessageContent
+ * is just intended as glue for wrapping a message programatically.
+ *
+ * @since WD.1
+ */
+class MessageContent extends AbstractContent {
+
+	/**
+	 * @var Message
+	 */
+	protected $mMessage;
+
+	/**
+	 * @param Message|String $msg    A Message object, or a message key
+	 * @param array|null     $params An optional array of message parameters
+	 */
+	public function __construct( $msg, $params = null ) {
+		# XXX: messages may be wikitext, html or plain text! and maybe even something else entirely.
+		parent::__construct( CONTENT_MODEL_WIKITEXT );
+
+		if ( is_string( $msg ) ) {
+			$this->mMessage = wfMessage( $msg );
+		} else {
+			$this->mMessage = clone $msg;
+		}
+
+		if ( $params ) {
+			$this->mMessage = $this->mMessage->params( $params );
+		}
+	}
+
+	/**
+	 * Returns the message as rendered HTML
+	 *
+	 * @return string The message text, parsed into html
+	 */
+	public function getHtml() {
+		return $this->mMessage->parse();
+	}
+
+	/**
+	 * Returns the message as rendered HTML
+	 *
+	 * @return string The message text, parsed into html
+	 */
+	public function getWikitext() {
+		return $this->mMessage->text();
+	}
+
+	/**
+	 * Returns the message object, with any parameters already substituted.
+	 *
+	 * @return Message The message object.
+	 */
+	public function getNativeData() {
+		//NOTE: Message objects are mutable. Cloning here makes MessageContent immutable.
+		return clone $this->mMessage;
+	}
+
+	/**
+	 * @see Content::getTextForSearchIndex
+	 */
+	public function getTextForSearchIndex() {
+		return $this->mMessage->plain();
+	}
+
+	/**
+	 * @see Content::getWikitextForTransclusion
+	 */
+	public function getWikitextForTransclusion() {
+		return $this->getWikitext();
+	}
+
+	/**
+	 * @see Content::getTextForSummary
+	 */
+	public function getTextForSummary( $maxlength = 250 ) {
+		return substr( $this->mMessage->plain(), 0, $maxlength );
+	}
+
+	/**
+	 * @see Content::getSize
+	 *
+	 * @return int
+	 */
+	public function getSize() {
+		return strlen( $this->mMessage->plain() );
+	}
+
+	/**
+	 * @see Content::copy
+	 *
+	 * @return Content. A copy of this object
+	 */
+	public function copy() {
+		// MessageContent is immutable (because getNativeData() returns a clone of the Message object)
+		return $this;
+	}
+
+	/**
+	 * @see Content::isCountable
+	 *
+	 * @return bool false
+	 */
+	public function isCountable( $hasLinks = null ) {
+		return false;
+	}
+
+	/**
+	 * @see Content::getParserOutput
+	 *
+	 * @return ParserOutput
+	 */
+	public function getParserOutput(
+		Title $title, $revId = null,
+		ParserOptions $options = null, $generateHtml = true
+	) {
+
+		if ( $generateHtml ) {
+			$html = $this->getHtml();
+		} else {
+			$html = '';
+		}
+
+		$po = new ParserOutput( $html );
+		return $po;
+	}
 }
 
-
+/**
+ * @since WD.1
+ */
 class JavaScriptContent extends TextContent {
-    public function __construct( $text ) {
-        parent::__construct($text, CONTENT_MODEL_JAVASCRIPT);
-    }
-
-    protected function getHtml( ) {
-        $html = "";
-        $html .= "<pre class=\"mw-code mw-js\" dir=\"ltr\">\n";
-        $html .= htmlspecialchars( $this->getNativeData() );
-        $html .= "\n</pre>\n";
-
-        return $html;
-    }
-
+	public function __construct( $text ) {
+		parent::__construct( $text, CONTENT_MODEL_JAVASCRIPT );
+	}
+
+	/**
+	 * Returns a Content object with pre-save transformations applied using
+	 * Parser::preSaveTransform().
+	 *
+	 * @param Title $title
+	 * @param User $user
+	 * @param ParserOptions $popts
+	 * @return Content
+	 */
+	public function preSaveTransform( Title $title, User $user, ParserOptions $popts ) {
+		global $wgParser;
+		// @todo: make pre-save transformation optional for script pages
+		// See bug #32858
+
+		$text = $this->getNativeData();
+		$pst = $wgParser->preSaveTransform( $text, $title, $user, $popts );
+
+		return new JavaScriptContent( $pst );
+	}
+
+
+	protected function getHtml( ) {
+		$html = "";
+		$html .= "<pre class=\"mw-code mw-js\" dir=\"ltr\">\n";
+		$html .= $this->getHighlightHtml( );
+		$html .= "\n</pre>\n";
+
+		return $html;
+	}
 }
 
+/**
+ * @since WD.1
+ */
 class CssContent extends TextContent {
-    public function __construct( $text ) {
-        parent::__construct($text, CONTENT_MODEL_CSS);
-    }
-
-    protected function getHtml( ) {
-        $html = "";
-        $html .= "<pre class=\"mw-code mw-css\" dir=\"ltr\">\n";
-        $html .= htmlspecialchars( $this->getNativeData() );
-        $html .= "\n</pre>\n";
-
-        return $html;
-    }
+	public function __construct( $text ) {
+		parent::__construct( $text, CONTENT_MODEL_CSS );
+	}
+
+	/**
+	 * Returns a Content object with pre-save transformations applied using
+	 * Parser::preSaveTransform().
+	 *
+	 * @param $title Title
+	 * @param $user User
+	 * @param $popts ParserOptions
+	 * @return Content
+	 */
+	public function preSaveTransform( Title $title, User $user, ParserOptions $popts ) {
+		global $wgParser;
+		// @todo: make pre-save transformation optional for script pages
+
+		$text = $this->getNativeData();
+		$pst = $wgParser->preSaveTransform( $text, $title, $user, $popts );
+
+		return new CssContent( $pst );
+	}
+
+
+	protected function getHtml( ) {
+		$html = "";
+		$html .= "<pre class=\"mw-code mw-css\" dir=\"ltr\">\n";
+		$html .= $this->getHighlightHtml( );
+		$html .= "\n</pre>\n";
+
+		return $html;
+	}
 }
-
-#FUTURE: special type for redirects?!
-#FUTURE: MultipartMultipart < WikipageContent (Main + Links + X)
-#FUTURE: LinksContent < LanguageLinksContent, CategoriesContent
-#EXAMPLE: CoordinatesContent
-#EXAMPLE: WikidataContent