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