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I am creating reporting system based on the yui DataSource/DataTable.

I will be reading report files from xml, each xml has a metadata section, something like this:



I then want to read the data from the same xml and display it in the table. Is there a way to do it with YUI - all the examples that I saw were using predefined columns.

What would be the best approach here?

That example is old and it might not be what you are looking for because it is further complicated by paging and sorting.

You would first use the asyncRequest method of Connection Manager to read your XML. Then you have to parse your colums definition and there is nothing much in YUI that can help you do that, you will have to use the regular XML DOM methods to go through it and build your columns definitions as you parse the data from the definition.

If your server could send the data in JSON format, this part would be much easier as using the YUI JSON parser would allow you to turn the incoming information into regular JavaScript objects and arrays and it would make it easier for you to parse.

In parallel with creating the column defs, you would have to create the responseSchema.fields array for the DataSource. Once the columns and fields definitions are created you would create a LocalDataSource instance passing it a reference to the XML node where the data records actually start.

The example you mention does this but it is further complicated because of the paging and sorting stuff while, on the other hand is simpler because the data comes in JSON and so it does not require you to use the XML DOM methods.

I am doubtful that you parsed XML and created JSON objects, what you probably did is that you created a series of JavaScript objects. JSON is a data format to represent data on a string.

I am quite sure that JSON should be faster on the client side and would consume much less memory, but I have no solid data for that, after all, decoding it, after doing the safety checks, is nothing more than running the interpreter on it and from then on you are working with plain JavaScript objects, not calling the XML DOM library for every step you want to take.

Googling for JSON vs XML provides plenty of links to articles discussing this.

You did the conversion on the server side? I thought you did it on the client side. Then you did, sorry. Check the www.json.org site to look for libraries that do the conversion for you. Converting to JSON is not so trivial, specially if you find umlauts and diacritical marks, which I believe you would find.

On the client side, don't eval() json to conver. Use the YUI JSON utility. If what you display in your tables is data that your visitors would have entered, if they enter as their last name
";alert("hello world!");"
that might get to your execute if you simply eval the data. The JSON utility will not execute that code injection.