YUI Library Examples: DataTable Control: Filtering of Dynamic Data

This example was contributed by Wayne Fincher (a.k.a. Floydian), proprietor of PHP Horizons.

When complex filtering of dynamic data is required, a custom generateRequest function is used to generate customized requests which are passed into DataSource's sendRequest method to populate the DataTable.

Sample Data:

CSS:

Markup:

<div id="genderRadioContainer">
	<p>Select a gender filter.</p>
	<input type="radio" name="gender" value="Both" checked>
	<input type="radio" name="gender" value="Female">
	<input type="radio" name="gender" value="Male">
</div>
<div id="stateSelectContainer">
	<p>Select states to compare.</p>
	<input type="button" class="menuButton" id="state1" value="State 1">
	<select id="state1Select">
		<option value="04000US01">Alabama</option>
		<option value="04000US02">Alaska</option>
		...
	</select>
	
	<input type="button" class="menuButton" id="state2" value="State 2">
	<select id="state2Select">
		<option value="04000US01">Alabama</option>
		<option value="04000US02">Alaska</option>
		...
	</select>
	
	<input type="button" class="menuButton" id="state3" value="State 3">
	<select id="state3Select">
		<option value="04000US01">Alabama</option>
		<option value="04000US02">Alaska</option>
		...
	</select>
</div>

Customizing the `generateRequest` Function

DataTable has a default generateRequest function which needs to be overridden in order to create a custom query string. Keep in mind that DataTable's if column sorting is enabled, the column sort state also needs to be taken into account. Although this example does not use enable DataTable's column sorting, the comments in the code indicate integration points for that feature. Here we define a custom function, this.requestBuilder, to generate requests to our server that reflect the user's filtration settings:

requestBuilder: function (oState, oSelf) {
		/* We aren't initializing sort and dir variables. If you are
		using column sorting built into the DataTable, use this
		set of variable initializers.
		var sort, dir, startIndex, results; */
		
		var startIndex, results;
		
		oState = oState || {pagination: null, sortedBy: null};
        
		/* If using column sorting built into DataTable, these next two lines
		will properly set the current _sortedBy_ column and the _sortDirection_
		sort = (oState.sortedBy) ? oState.sortedBy.key : oSelf.getColumnSet().keys[0].getKey();
		dir = (oState.sortedBy && oState.sortedBy.dir === DataTable.CLASS_DESC) ? "desc" : "asc"; */
		
		startIndex = (oState.pagination) ? oState.pagination.recordOffset : 0;
		results = (oState.pagination) ? oState.pagination.rowsPerPage : null;
		
		return  "&results=" 	+ results +
				"&startIndex=" 	+ startIndex +
			    "&state[1]=" 	+ CF.settings.state1 +
			    "&state[2]=" 	+ CF.settings.state2 +
			    "&state[3]=" 	+ CF.settings.state3 +
			    "&gender=" 		+ CF.settings.gender;
	},

The custom function this.requestBuilder is then passed in as the generateRequest value.

Sending Requests

When the user interacts with the MenuButton controls to trigger requests for filtered data, our custom generateRequest function provides the proper request string to DataSource's sendRequest method, which also requires a callback object.

This callback accepts four properties that are very important here.

success
failure: There are four methods built into DataTable for handling the success and failure events. Please refer to Loading Data at Runtime for a list of the four methods and a description of each. It should suffice to say that, for this example, onDataReturnSetRows is what is required.
argument: The DataTable's state -- the return value from getState() -- is passed as the argument value. If any changes to the Paginator UI need to be done, those changes should to be reflected in this state object. For example, if the page needs to be reset to 1, set that here and the Paginator will be updated to reflect that value when the data is returned.
scope: Pass in your instance of the DataTable.

fireDT: function (resetRecordOffset) {
        var oState = CF.myDataTable.getState(),
        	request,
        	oCallback;
    	
		/* We don't always want to reset the recordOffset.
		If we want the Paginator to be set to the first page,
		pass in a value of true to this method. Otherwise, pass in
		false or anything falsy and the Paginator will remain at the
		page it was set at before.*/
        if (resetRecordOffset) {
        	oState.pagination.recordOffset = 0;
        }
		
		/* If the column sort direction needs to be updated, that may be done here.
		It is beyond the scope of this example, but the DataTable::sortColumn() method
		has code that can be used with some modification. */
        
		/*
		This example uses onDataReturnSetRows because that method
		will clear out the old data in the DataTable, making way for
		the new data.*/
		oCallback = {
		    success : CF.myDataTable.onDataReturnSetRows,
		    failure : CF.myDataTable.onDataReturnSetRows,
            argument : oState,
		    scope : CF.myDataTable
		};
        
		// Generate a query string
        request = CF.myDataTable.get("generateRequest")(oState, CF.myDataTable);
		
		// Fire off a request for new data.
		CF.myDataSource.sendRequest(request, oCallback);
	}

Handling the Response

In order to update the Paginator's totalRecords value as the data is returned, override the DataTable's handleDataReturnPayload method. This will enable the Paginator to calculate how many pages of data have been returned for each request at runtime. The rest of the work is done for us automatically through the oCallback object set in our sendRequest method call.

Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.

YUI Library Examples: DataTable Control: Filtering of Dynamic Data

Customizing the `generateRequest` Function

Sending Requests

Handling the Response

Configuration for This Example

DataTable Control Examples:

More DataTable Control Resources:

YUI Library Examples: DataTable Control: Filtering of Dynamic Data

DataTable Control: Filtering of Dynamic Data

Customizing the generateRequest Function

Sending Requests

Handling the Response

Configuration for This Example

DataTable Control Examples:

More DataTable Control Resources:

Customizing the `generateRequest` Function