silverstripe-framework/admin/thirdparty/jquery-changetracker/lib/jquery.changetracker.js

// Copyright (c) 2009, SilverStripe Ltd.
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the <organization> nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY SilverStripe Ltd. ''AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL SilverStripe Ltd. BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

/**
 * @class Tracks onchange events on all form fields.
 * 
 * @todo Implement form reset handling
 *  
 * @name jQuery.changetracker
 * @author Ingo Schommer, SilverStripe Ltd.
 * @license BSD License
 */
(function($) {
  $.fn.changetracker = function(_options) {
    var self = this;

    if(this.length > 1){
      this.each(function(i, item) {
        this.changetracker(_options);
      });
      return this;
    }

    this.defaults = {
      fieldSelector: ':input:not(:submit)',
      ignoreFieldSelector: "",
      changedCssClass: 'changed'
    };

    var options = $.extend({}, this.defaults, _options);

    this.initialize = function() {
      // optional metadata plugin support
      if ($.meta) options = $.extend({}, options, this.data());

      // Flag indicating this form was dirtied by an external component
      var dirty = false;
      
      // Get value from field for purposes of change tracking
      var fieldValue = function($field) {
        // Get radio
        if ($field.is(':radio')) {
          var checkedItems = self.find(':input[name=' + $field.attr('name') + ']:checked');
          return checkedItems.length ? checkedItems.val() : 0;
        }
        
        if($field.is(':checkbox')) {
          return $field.is(':checked') ? 1 : 0;
        }
        
        return $field.val();
      }

      var onchange = function(e) {
        var $field = $(e.target);
        var origVal = $field.data('changetracker.origVal'), newVal;

        // Determine value based on field type
        newVal = fieldValue($field);

        // Determine changed state based on value comparisons
        if(origVal === null || newVal != origVal) {
          $field.addClass(options.changedCssClass);
          self.addClass(options.changedCssClass);
        } else {
          $field.removeClass(options.changedCssClass);
          // Unset changed state on all radio buttons of the same name
          if($field.is(':radio')) {
            self.find(':radio[name=' + $field.attr('name') + ']').removeClass(options.changedCssClass);
          }
          // Only unset form state if no other fields are changed as well and the form isn't explicitly dirty
          if(!dirty && !self.getFields().filter('.' + options.changedCssClass).length) {
            self.removeClass(options.changedCssClass);
          }
        }
      };

      // setup original values
      var fields = this.getFields(), origVal;
      fields.filter(':radio,:checkbox').bind('click.changetracker', onchange);
      fields.not(':radio,:checkbox').bind('change.changetracker', onchange);
      fields.each(function() {
        origVal = fieldValue($(this));
        $(this).data('changetracker.origVal', origVal);
      });

      self.bind('dirty.changetracker', function() {
        dirty = true;
        self.addClass(options.changedCssClass);
      });

      this.data('changetracker', true);
    };

    this.destroy = function() {
      this.getFields()
        .unbind('.changetracker')
        .removeClass(options.changedCssClass)
        .removeData('changetracker.origVal');
      this.unbind('.changetracker')
        .removeData('changetracker');
    };

    /**
     * Reset change state of all form fields and the form itself.
     */
    this.reset = function() {
      this.getFields().each(function() {
        self.resetField(this);
      });

      this.removeClass(options.changedCssClass);
    };

    /**
     * Reset the change single form field.
     * Does not reset to the original value.
     *
     * @param DOMElement field
     */
    this.resetField = function(field) {
      return $(field).removeData('changetracker.origVal').removeClass('changed');
    };

    /**
     * @return jQuery Collection of fields
     */
    this.getFields = function() {
      return this.find(options.fieldSelector).not(options.ignoreFieldSelector);
    };

    // Support invoking "public" methods as string arguments
    if (typeof arguments[0] === 'string') {
      var property = arguments[1];
      var args = Array.prototype.slice.call(arguments);
      args.splice(0, 1);
      return this[arguments[0]].apply(this, args);
    } else {
      return this.initialize();
    }

  };
}(jQuery));