When Written: Aug 2007
One AJAX library that I haven’t mentioned yet and nor does the book, and that is ‘Spry’. This is the Adobe AJAX library which I have written about in this column before. Adobe’s documentation is good and it is not too difficult to use this library, however it is a case of adding code manually, or rather was, until now. The latest version of Dreamweaver which is called CS3, in line with the other Adobe products, now has support for the SPRY Framework amongst several other new features. I thought I would take a quick look at a couple of the new features of Dreamweaver that for my money make the upgrade worth the cost. Firstly as I have just mentioned is its support for AJAX in the form of the SPRY Framework. To use these features it’s simply a click on the SPRY tool bar and a dialog box opens up, you simply fill in the details and that is about it, your first bit of AJAX!
So what features does the SPRY Framework give you? Firstly there is a simple collapsible panel which enables content to be hidden on a page which expands out when the user clicks on the top bar of the panel. The content is already on the page so you are not saving anything on the page file size, but it is an interesting way of getting a lot of content into a smaller area of browser space. A slightly more complex version of this which allows multiple areas is the Accordion object. Then there are the inevitable Tabbed panels object and the vertical and Horizontal Menu objects. These menu objects allow you to build dynamic dropdown menus in a very simple way. This, in my book, is greatly preferable to the way that some of the menu builders work. Whilst they are quite flexible and seem to work well, they often generate code which is almost impossible to understand or edit without the builder program. This can give problems integrating it into your web site if others are to edit the content later and may need to edit the menu. The next set of four SPRY objects are validation objects for Form objects and can be used to make sure the user has entered data correctly on a web form.
A point worth noting here is that the datasets that these objects expect to work with are XML datasets. The examples provided hold their data in a series of XML files, not really a very convincing demonstration. Let’s face it if you were designing a website with dynamic content, there would be a database somewhere and it is this content you would want to display. So if you wanted to use these objects you would either have to create a web service which would query your database and return an XML data feed or another way might be to use a newish addition to the syntax of SQL Server, which converts any query to produce an XML data stream. Say you wanted the query ‘SELECT * FROM MYTABLE’ to return an XML data stream, then all you need to do is change the query to ‘SELECT * FROM MYTABLE FOR XML AUTO’. Its as simple as that.
Article by: Mark Newton
Published in: Mark Newton