Adding AutoCompleteExtenders dynamically on client side

In my current efforts to build rich client webforms in html/javascript I came across a need to dynamically add an AutoCompleteExtender for a newly created element on the page. Basically the page contains a table which the user can click an “Add” button to add a new row, and in each new row I wanted the user to get autocomplete functionality without a round trip to the server.


Upon inspecting the rendered page containing an AutoCompleteExtender we will see the following javascript:


1 Sys.Application.add_init(function() {
2     $create(Sys.Extended.UI.AutoCompleteBehavior, {"completionInterval":500,"completionListCssClass":"AutoExtender","completionListItemCssClass":"AutoExtenderList","completionSetCount":20,"delimiterCharacters":"","highlightedItemCssClass":"AutoExtenderHighlight","id":"acAccessory","minimumPrefixLength":2,"serviceMethod":"GetSuggestions","servicePath":"../../AJAX/Products.asmx"}, {"itemSelected":ItemSelected}, null, $get("MyClientID"));
3 });


So, we can see that the autocompleteextender registers an initialization function to create the autocomplete functionality for a given control’s clientID. We can take that same code and put it in our javascript (such as the onclick handler for the “Add” button) and use it to add autocomplete to any text input we like.

Here is my function that adds a new row to the table and gives one of the text inputs autocomplete:


01 function AddUpgradeOption(index, name, price, productId)
02 {
03     var row = tblOptions.insertRow(tblOptions.rows.length);
04     var cell = row.insertCell(0);
05     cell.innerHTML = 'Name: <input type="text">';
06     var cell = row.insertCell(1);
07     cell.innerHTML = 'Price: <input type="text">';
08     var cell = row.insertCell(2);
09     cell.innerHTML = 'Select Item: <input id="txtSearchItem' + index + '" type="text">';
11     $create(Sys.Extended.UI.AutoCompleteBehavior,
12     {"completionInterval":500,
13     "completionListCssClass":"AutoExtender",
14     "completionListItemCssClass":"AutoExtenderList",
15     "completionSetCount":20,"delimiterCharacters":"",
16     "highlightedItemCssClass": "AutoExtenderHighlight",
17     "id": "AutoComplete1",
18     "minimumPrefixLength": 2,
19     "serviceMethod": "GettSuggestions",
20     "servicePath": "../../AJAX/Products.asmx"
21 },
22      { "itemSelected": ItemSelected }, null, $get("txtSearchItem" + index));
23 }



You will of course need to have at least one server-side autocompleteextender on the page to start with so that the necessary javascript resources are included in the page.

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