I stumbled upon an interested dilemma recently whilst building a search engine. The results of a search are returned, and can be viewed in a list or thumbnail view. The view toggle is a uses a JQuery function, so no persistent data is stored concerning a users current viewing option. The dilemma is how do you maintain the viewing mode across page reloads, such as for pagination, or filtering of the search results?

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Rather than writing out long winded table code to display your data in a tabulated fashion why not use the dataTables JQuery plugin to do it for you?

In this blog entry I'll be generating tables using a JQuery plugin, but I will also be generating the JQuery code from an XML document.

The theory behind the dataTables JQuery plugin is that when the template loads it makes an AJAX request to a remotely specified template. That template returns a JSON object of data which is formatted and used in a tabular display. This means that you can perfom filtering and sort functions inline, and the JQuery simply re submits the AJAX request, receiving new JSON each time. So no refreshing.

I'll be dealing with the auto generation of the JSON back end in the second part of this article. Here is how I setup the tabular display.

Build a standard html template, including the CSS and JQuery plugins.

Next we build our JQuery function. I wont go into massive detail about all the parameters and values being passed in here, but it is well documented on http://www.datatables.net/.

The really important column here is the "aoColumns" JSON data block. This specifies what fields are returned from your AJAX call, and parameters they must adhere to.

In this example we are anticipating that we will receive four columns of data back (Edit,Band,Genre and Fake Column).

Lastly we create a table with an ID of "example", as this is what the JQuery is looking for. This table must be formatted in a certain way, as the JQuery plugin will re write the specified elements.

The code also contains the header elements that will match the returned column values from the AJAX request. The last part of the table is displayed when the data is loading.

This all works well, but to extend it further I have altered the code to read from an XML document. The XML document Is loaded when the template starts, and the data fields and attributes are read, and looped over to create the JQuery code and table headers. In this way it is a generic table display template, driven from an XML document.

The XML doc:

Read the XML file and parse it out into an Array:

Use something like this to dynamically generate the JQuery and table values:

The JSON response is hard coded in this example, so the result will not filter or search. I'll handle that in article two.

There is a full example of this here.

Most of us are familiar with the standard method of displaying data in a tabulated fashion, selecting a record, and populating the form that follows. What about editing the content directly into a template that mirrors the actual live version of a page?

This article examines how to edit web content directly inline, and commit it back to a server using an AJAX post request.

The main catalyst for this is that clients that use a content management system do not often have a clear image of how their content will look online. The traditional form layout for entering text does not lend itself well to representing the actual content in the format it is display in.

The aim here is to build a flexible system that allows for inline content editing, and saves it gracefully to a server based database.

I will start by saying thank you to Peter-Paul Koch. His article here (http://www.quirksmode.org/dom/cms.html) on making content editable was invaluable, and a lot of this is based on his theory.

We start by setting a value "editing" to false. This is the default for the page, as the user isn't editing anything when the page loads.

I wont go into massive depth on a line by line basis but Peter's article does break this down a lot. The premise is that there is a function catchit(), which will intercept any click events. It will then check that the event was triggered from a 'P' tag, which is our defining element for editable content. IE any P elements hold editable content. It will then remove the P html container, replacing it with a textarea, and re insert the P tags previous html content using the innerHTML JavaScript function.

In this way we can create editable inline textareas within the framework of our page.

The next step is to create a save function. The function 'saveToServer{)' take several arguments. It needs the value to commit, IE what the amended text string is, and the fieldname. Each 'P' tag has an id that I am matching to a data field. In this way if there are multiple p tags in a display they can each be attributed to a specific storage field in a database.

Because we are destroying the 'P' tag when we create the textarea we need to re assign the id to it when we save. We can do this by using the JavaScript function 'setAttribute'. The setAttribute function is used to set the value of an attribute on an object. It is typically used along with objects returned by document.getElementById to assign a new value to the object's attribute.

If we don't do this then the recreated 'P' tag no longer has an id attribute, so will error on any subsequent updates.

Next we use a JQuery Post function to post the values through an AJAX request.

This will post the values to the cfml CFC "commitChange.cfc", which handles them in a function.

This will allow you to perform seamless inline edits to the display layer, and commit them back to a server, so they are stored in real time.

There is an example of this here. (Minus the storing). You can track the AJAX post using a tool like charles http proxy, or firefox's firebug.

Now, to write a nice JQuery response handler to fade the returned massage in and out.