1 (function($) {

     2     $.fn.prepopulate = function(dependencies, maxLength) {

     3         /*

     4             Depends on urlify.js

     5             Populates a selected field with the values of the dependent fields,

     6             URLifies and shortens the string. 

     7             dependencies - selected jQuery object of dependent fields

     8             maxLength - maximum length of the URLify'd string 

     9         */

    10         return this.each(function() {

    11             var field = $(this);

    12 

    13             field.data('_changed', false);

    14             field.change(function() {

    15                 field.data('_changed', true);

    16             });

    17 

    18             var populate = function () {

    19                 // Bail if the fields value has changed

    20                 if (field.data('_changed') == true) return;

    21  

    22                 var values = [];

    23                 dependencies.each(function() {

    24                     if ($(this).val().length > 0) {

    25                         values.push($(this).val());

    26                     }

    27                 });

    28                 field.val(URLify(values.join(' '), maxLength));

    29             };

    30 

    31             dependencies.keyup(populate).change(populate).focus(populate);

    32         });

    33     };

    34 })(django.jQuery);