API: Allow for format modules that cannot handle errors

ApiFormatFeedWrapper, for example, has nothing particularly useful to do
when given an API error to print. So allow for punting errors to the
default formatter instead.

Bug: 63150
Change-Id: Ifc034d4c7861905e382c42dc22585f0cd2beaf3f

diff --git a/includes/api/ApiFormatBase.php b/includes/api/ApiFormatBase.php
index 3c924bc..d43259d 100644 (file)
--- a/includes/api/ApiFormatBase.php
+++ b/includes/api/ApiFormatBase.php
@@ -120,6 +120,16 @@ abstract class ApiFormatBase extends ApiBase {
                return $this->mDisabled;
        }
 
+       /**
+        * Whether this formatter can handle printing API errors. If this returns
+        * false, then on API errors the default printer will be instantiated.
+        * @since 1.23
+        * @return bool
+        */
+       public function canPrintErrors() {
+               return true;
+       }
+
        /**
         * Initialize the printer function and prepare the output headers, etc.
         * This method must be the first outputting method during execution.
@@ -377,6 +387,15 @@ class ApiFormatFeedWrapper extends ApiFormatBase {
                return true;
        }
 
+       /**
+        * ChannelFeed doesn't give us a method to print errors in a friendly
+        * manner, so just punt errors to the default printer.
+        * @return false
+        */
+       public function canPrintErrors() {
+               return false;
+       }
+
        /**
         * This class expects the result data to be in a custom format set by self::setResult()
         * $result['_feed'] - an instance of one of the $wgFeedClasses classes

diff --git a/includes/api/ApiMain.php b/includes/api/ApiMain.php
index e1c0874..f7c776d 100644 (file)
--- a/includes/api/ApiMain.php
+++ b/includes/api/ApiMain.php
@@ -641,6 +641,7 @@ class ApiMain extends ApiBase {
                global $wgShowHostnames;
 
                $result = $this->getResult();
+
                // Printer may not be initialized if the extractRequestParams() fails for the main module
                if ( !isset( $this->mPrinter ) ) {
                        // The printer has not been created yet. Try to manually get formatter value.
@@ -650,11 +651,18 @@ class ApiMain extends ApiBase {
                        }
 
                        $this->mPrinter = $this->createPrinterByName( $value );
-                       if ( $this->mPrinter->getNeedsRawData() ) {
-                               $result->setRawMode();
-                       }
                }
 
+               // Printer may not be able to handle errors. This is particularly
+               // likely if the module returns something for getCustomPrinter().
+               if ( !$this->mPrinter->canPrintErrors() ) {
+                       $this->mPrinter->safeProfileOut();
+                       $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
+               }
+
+               // Update raw mode flag for the selected printer.
+               $result->setRawMode( $this->mPrinter->getNeedsRawData() );
+
                if ( $e instanceof UsageException ) {
                        // User entered incorrect parameters - print usage screen
                        $errMessage = $e->getMessageArray();

diff --git a/includes/api/ApiResult.php b/includes/api/ApiResult.php
index e922020..0cbfcc8 100644 (file)
--- a/includes/api/ApiResult.php
+++ b/includes/api/ApiResult.php
@@ -80,9 +80,11 @@ class ApiResult extends ApiBase {
        /**
         * Call this function when special elements such as '_element'
         * are needed by the formatter, for example in XML printing.
+        * @since 1.23 $flag parameter added
+        * @param bool $flag Set the raw mode flag to this state
         */
-       public function setRawMode() {
-               $this->mIsRawMode = true;
+       public function setRawMode( $flag = true ) {
+               $this->mIsRawMode = $flag;
        }
 
        /**