Recently a new version of jQuery was released. This version is 1.4. As with any new version, ultimately you see what used to take you several lines of code, now rolled up into a single line of code. I'm going to demonstrate a question I've been asked many times on forums and that is how to move selected items from onehere.
The HTML
The HTML for this is pretty straight forward. It's simply two
<form method="get">
<select id="SelectLeft" multiple="multiple">
<option value="1">Australiaoption>
<option value="2">New Zealandoption>
<option value="3">Canadaoption>
<option value="4">USAoption>
<option value="5">Franceoption>
select>
<input id="MoveRight" type="button" value=" >> " />
<input id="MoveLeft" type="button" value=" << " />
<select id="SelectRight" multiple="multiple">
select>
form>
jQuery 1.3.2
Below is the code to move the selected items from each
<script language="javascript" type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js">script>
<script language="javascript" type="text/javascript">
$(function() {
$("#MoveRight,#MoveLeft").click(function(event) {
var id = $(event.target).attr("id");
var selectFrom = id == "MoveRight" ? "#SelectLeft" : "#SelectRight";
var moveTo = id == "MoveRight" ? "#SelectRight" : "#SelectLeft";
var selectedItems = $(selectFrom + "option:selected");
var output = [];
$.each(selectedItems, function(key, e) {
output.push('');
});
$(moveTo).append(output.join(""));
selectedItems.remove();
});
});
script>
I've bound one event handler for the button clicks. To decide which direction the selected items should go, I'm using the ID of the button that fired the event:
var id = $(event.target).attr("id");
var selectFrom = id == "MoveRight" ? "#SelectLeft" : "#SelectRight";
var moveTo = id == "MoveRight" ? "#SelectRight" : "#SelectLeft";
Next I create an empty array and loop through every selected item and add it to the end of the array:
var output = [];
$.each(selectedItems, function(key, e) {
output.push('');
});
Then I append it to the end of the
$(moveTo).append(output.join(""));
selectedItems.remove();
Overall I think that's a good approach. In jQuery 1.4 we can make this better!
jQuery 1.4
In the new jQuery library, the team has introduced a new function called toArray. This retrieves all the DOM elements contained in the jQuery set, as an array. So here's the code below:
<script language="javascript" type="text/javascript" src="http://code.jquery.com/jquery-1.4.1.min.js">script>
<script language="javascript" type="text/javascript">
$(function() {
$("#MoveRight,#MoveLeft").click(function(event) {
var id = $(event.target).attr("id");
var selectFrom = id == "MoveRight" ? "#SelectLeft" : "#SelectRight";
var moveTo = id == "MoveRight" ? "#SelectRight" : "#SelectLeft";
var selectedItems = $(selectFrom + " :selected").toArray();
$(moveTo).append(selectedItems);
selectedItems.remove;
});
});
script>
The first thing you'll notice is the code has been reduced. Thanks to the toArray function, I have eliminated the need to loop through the selected items. Now they're returned as an array:
var selectedItems = $(selectFrom + " :selected").toArray();
And to add them to the
$(moveTo).append(selectedItems);
Nice and simple! The entire source code of this article can be downloaded over here
No comments:
Post a Comment