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script.aculo.us - Auto Completion
  • 时间:2024-11-03

script.aculo.us - Auto Completion


Out of the box, script.aculo.us supports two sources for auto-completion −

    Remote sources (obtained through Ajax),

    Local sources (string arrays in your web page s scripts).

Depending on the source you re planning to use, you ll instantiate Ajax.Autocompleter or Autocompleter.Local, respectively. Although equipped with specific options, these two objects share a large feature set and provide a uniform user experience.

There are four things you ll always pass to these objects while building them −

    The text field you want to make autocompletable. As usual, you can pass the field itself or the value of its id = attribute.

    The container for autocompletion choices, which will end up holding a <ul></p> pst of options to pick from. Again, pass the element directly or its id =. This element is most often a simple <span>.</p></p>

    The data source, which will be expressed, depending on the source type, as a JavaScript array of strings or as a URL to the remote source.

    Finally, the options. As always, they re provided as a hash of sorts, and both autocompletion objects can make do with no custom option; there are suitable defaults for everything.

To use script.aculo.us s autocompletion capabipties, you ll need to load the controls.js and effects.js modules along with the prototype.js module. So, your minimum loading for script.aculo.us will look pke this −

<script type = "text/javascript" src = "/javascript/prototype.js"></script>
<script type = "text/javascript"  src = "/javascript/scriptaculous.js?load = effects,controls"></script>

Creating an Ajax Auto-Completer

The construction syntax is as follows −

new Ajax.Autocompleter(element, container, url [ , options ] )

The constructor for the Ajax.Autocompleter accepts four parameters −

    The element name or reference to a text field that is to be populated with a data choice.

    The element name or reference to a <span> element to be used as a menu of choices by the control.

    The URL of the server-side resource that will supply the choices.

    The usual options hash.

Options

You can use one or more of the following options while creating your Ajax.Autocompleter object.

Sr.No Option & Description
1

paramName

The name of the query parameter containing the content of the text field that is posted to the server-side resource. Defaults to the name of the text field.

2

minChars

Number of characters that must be entered before a server-side request for choices can be fired off. Defaults to 1.

3

Frequency

The interval, in seconds, between internal checks to see if a request to the server-side resource should be posted. Defaults to 0.4.

4

Indicator

The id or reference to an element to be displayed while a server-side request for choices is underway. If omitted, no element is revealed.

5

Parameters

A text string containing extra query parameters to be passed to the server-side resource.

6

updateElement

A callback function to be triggered when the user selects one of the choices returned from the server that replaces the internal function that updates the text field with the chosen value.

7

afterUpdateElement

A callback function to be triggered after the updateElement function has been executed.

8

Tokens

A single text string, or array of text strings that indicate tokens to be used as depmiters to allow multiple elements to be entered into the text field, each of which can be auto-completed inspanidually.

Example

<html>
   <head>
      <title>Simple Ajax Auto-completer Example</title>
		
      <script type = "text/javascript" src = "/javascript/prototype.js"></script>
      <script type = "text/javascript" src = "/javascript/scriptaculous.js?load = effects,controls"></script>
      
      <script type = "text/javascript">
         window.onload = function() {
            new Ajax.Autocompleter(
                autoCompleteTextField ,
                autoCompleteMenu ,
                /script.aculo.us/serverSideScript.php , {}
            );
         }
      </script>
   </head>
   
   <body>
      <p>Type something in this box and then select suggested option from the pst </p>

      <span>
         <label>Text field:</label>
         <input type = "text" id = "autoCompleteTextField"/>
         <span id = "autoCompleteMenu"></span>
      </span>
   </body>
</html>

Now, we need a server side to access this page and serve the data source URL (serverSideScript.php). You will keep a complete logic to display suggestions in this script.

Just for example, we are keeping a simple HTML text in serverSideScript.php. You can write your script using CGI, PHP, Ruby, or any other server side scripting to choose appropriate suggestions and format them in the form of <ul><p>...</p></ul> and pass them back to the caller program.

<ul>
   <p>One</p>
   <p>Two</p>
   <p>Three</p>
   <p>Four</p>
   <p>Five</p>
   <p>Six</p>
</ul>

This will produce following result −