resources/jquery/jquery.placeholder.js

   1 /**
   2  * HTML5 placeholder emulation for jQuery plugin
   3  *
   4  * This will automatically use the HTML5 placeholder attribute if supported, or emulate this behavior if not.
   5  *
   6  * @author Trevor Parscal <tparscal@wikimedia.org>, 2012
   7  * @author Krinkle <krinklemail@gmail.com>, 2012
   8  * @version 0.2.0
   9  * @license GPL v2
  10  */
  11 ( function ( $ ) {
  12
  13         $.fn.placeholder = function ( text ) {
  14                 var hasArg = arguments.length;
  15
  16                 return this.each( function () {
  17                         var placeholder, $input;
  18
  19                         if ( hasArg ) {
  20                                 this.setAttribute( 'placeholder', text );
  21                         }
  22
  23                         // If the HTML5 placeholder attribute is supported, use it
  24                         if ( this.placeholder && 'placeholder' in document.createElement( this.tagName ) ) {
  25                                 return;
  26                         }
  27
  28                         placeholder = hasArg ? text : this.getAttribute( 'placeholder' );
  29                         $input = $(this);
  30
  31                         // Show initially, if empty
  32                         if ( this.value === '' || this.value === placeholder ) {
  33                                 $input.addClass( 'placeholder' ).val( placeholder );
  34                         }
  35
  36                         $input
  37                                 // Show on blur if empty
  38                                 .blur( function () {
  39                                         if ( this.value === '' ) {
  40                                                 this.value = placeholder;
  41                                                 $input.addClass( 'placeholder' );
  42                                         }
  43                                 } )
  44
  45                                 // Hide on focus
  46                                 // Also listen for other events in case $input was
  47                                 // already focused when the events were bound
  48                                 .on( 'focus drop keydown paste', function ( e ) {
  49                                         if ( $input.hasClass( 'placeholder' ) ) {
  50                                                 if ( e.type === 'drop' && e.originalEvent.dataTransfer ) {
  51                                                         // Support for drag&drop. Instead of inserting the dropped
  52                                                         // text somewhere in the middle of the placeholder string,
  53                                                         // we want to set the contents of the search box to the
  54                                                         // dropped text.
  55
  56                                                         // IE wants getData( 'text' ) but Firefox wants getData( 'text/plain' )
  57                                                         // Firefox fails gracefully with an empty string, IE barfs with an error
  58                                                         try {
  59                                                                 // Try the Firefox way
  60                                                                 this.value = e.originalEvent.dataTransfer.getData( 'text/plain' );
  61                                                         } catch ( exception ) {
  62                                                                 // Got an exception, so use the IE way
  63                                                                 this.value = e.originalEvent.dataTransfer.getData( 'text' );
  64                                                         }
  65
  66                                                         // On Firefox, drop fires after the dropped text has been inserted,
  67                                                         // but on IE it fires before. If we don't prevent the default action,
  68                                                         // IE will insert the dropped text twice.
  69                                                         e.preventDefault();
  70                                                 } else {
  71                                                         this.value = '';
  72                                                 }
  73                                                 $input.removeClass( 'placeholder' );
  74                                         }
  75                                 } );
  76
  77                         // Blank on submit -- prevents submitting with unintended value
  78                         if ( this.form ) {
  79                                 $( this.form ).submit( function () {
  80                                         // $input.trigger( 'focus' ); would be problematic
  81                                         // because it actually focuses $input, leading
  82                                         // to nasty behavior in mobile browsers
  83                                         if ( $input.hasClass( 'placeholder' ) ) {
  84                                                 $input
  85                                                         .val( '' )
  86                                                         .removeClass( 'placeholder' );
  87                                         }
  88                                 });
  89                         }
  90
  91                 });
  92         };
  93
  94 }( jQuery ) );