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