Implemented #753

[jquery.git] / src / jquery / jquery.js

diff --git a/src/jquery/jquery.js b/src/jquery/jquery.js
index e3699ae..b6d1dec 100644 (file)
--- a/src/jquery/jquery.js
+++ b/src/jquery/jquery.js
@@ -388,6 +388,8 @@ jQuery.fn = jQuery.prototype = {
        /**
         * Set a single property to a value, on all matched elements.
         *
+        * Can compute values provided as ${formula}, see second example.
+        *
         * Note that you can't set the name property of input elements in IE.
         * Use $(html) or .append(html) or .html(html) to create elements
         * on the fly including the name property.
@@ -397,12 +399,34 @@ jQuery.fn = jQuery.prototype = {
         * @result <img src="test.jpg"/>
         * @desc Sets src attribute to all images.
         *
+        * @example $("img").attr("title", "${this.src}");
+        * @before <img src="test.jpg" />
+        * @result <img src="test.jpg" title="test.jpg" />
+        * @desc Sets title attribute from src attribute, a shortcut for attr(String,Function)
+        *
         * @name attr
         * @type jQuery
         * @param String key The name of the property to set.
         * @param Object value The value to set the property to.
         * @cat DOM/Attributes
         */
+        
+       /**
+        * Set a single property to a computed value, on all matched elements.
+        *
+        * Instead of a value, a function is provided, that computes the value.
+        *
+        * @example $("img").attr("title", function() { return this.src });
+        * @before <img src="test.jpg" />
+        * @result <img src="test.jpg" title="test.jpg" />
+        * @desc Sets title attribute from src attribute.
+        *
+        * @name attr
+        * @type jQuery
+        * @param String key The name of the property to set.
+        * @param Function value A function returning the value to set.
+        * @cat DOM/Attributes
+        */
        attr: function( key, value, type ) {
                // Check to see if we're setting style values
                return typeof key != "string" || value != undefined ?
@@ -413,15 +437,17 @@ jQuery.fn = jQuery.prototype = {
                                        for ( var prop in key )
                                                jQuery.attr(
                                                        type ? this.style : this,
-                                                       prop, key[prop]
+                                                       prop, jQuery.parseSetter(key[prop])
                                                );
 
                                // See if we're setting a single key/value style
-                               else
+                               else {
+                                       // convert ${this.property} to function returnung that property
                                        jQuery.attr(
                                                type ? this.style : this,
-                                               key, value
+                                               key, jQuery.parseSetter(value)
                                        );
+                               }
                        }) :
 
                        // Look for the case where we're accessing a style value
@@ -742,7 +768,7 @@ jQuery.fn = jQuery.prototype = {
         * @example $("p").find("span").end();
         * @before <p><span>Hello</span>, how are you?</p>
         * @result [ <p>...</p> ]
-        * desc Selects all paragraphs, finds span elements inside these, and reverts the
+        * @desc Selects all paragraphs, finds span elements inside these, and reverts the
         * selection back to the paragraphs.
         *
         * @name end
@@ -1363,6 +1389,16 @@ jQuery.extend({
                return r;
        },
        
+       parseSetter: function(value) {
+               if( typeof value == "string" && value[0] == "$" ) {
+                       var m = value.match(/^\${(.*)}$/);
+                       if ( m && m[1] ) {
+                               value = new Function( "return " + m[1] );
+                       }
+               }
+               return value;
+       },
+       
        attr: function(elem, name, value){
                var fix = {
                        "for": "htmlFor",
@@ -1378,6 +1414,11 @@ jQuery.extend({
                        selected: "selected"
                };
                
+               // get value if a function is provided
+               if ( value && typeof value == "function" ) {
+                       value = value.apply( elem );
+               }
+               
                // IE actually uses filters for opacity ... elem is actually elem.style
                if ( name == "opacity" && jQuery.browser.msie && value != undefined ) {
                        // IE has trouble with opacity if it does not have layout
@@ -1579,7 +1620,7 @@ jQuery.extend({
                        }
                }
 
-               var r = [ result[0] ];
+               var r = result.length ? [ result[0] ] : [];
 
                check: for ( var i = 1, rl = result.length; i < rl; i++ ) {
                        for ( var j = 0; j < i; j++ )
@@ -2112,4 +2153,4 @@ jQuery.each( [ "eq", "lt", "gt", "contains" ], function(i,n){
        jQuery.fn[ n ] = function(num,fn) {
                return this.filter( ":" + n + "(" + num + ")", fn );
        };
-});
\ No newline at end of file
+});