I've been working with some client side flash developers recently and we came across an unusual error that was being thrown in a Flex application when we were sending a webservice request to a Coldfusion server.

The error was "Security error accessing URL". I thought I'd overcome this a long time ago by using the cross-domain.xml file to allow server access to services.

It appears that there is a security issue with Flash 9 that requires the following line to be added to the CrossDomain.xml file:

I'm guessing that it is enabling access for SOAP requests to any remote services on that server.

Having been using Flex a little more recently I stumbled upon an old issue that I had previously addressed, but it had become second nature, and so I had forgotten about having to learn a workaround in the past. Passing objects from ColdFusion to Flex can be tricky at times, especially as ColdFusion is generally not case sensitive, but Flex is, and this can lead to problems.

I had previously found that how you build your Structure will have an impact the case of the keys. Example one is a Structure built using the traditional dot notation, in a CF 7 and below method:

This is the older way of building a Structure, notice how all the keys are uppercase.

The second example is very similar, except that it is using associative array notation, IE brackets to denote the key values, rather than dot notation.

Since I originally looked at this ColdFusion 8 (and now 9!) have been released. ColdFusion 8 introduced a new way of creating structures, what casing does this use?

It also creates an uppercase structure. I haven't really played around with this method enough to see if there is another way of creating a lowercase structure, so for now I'll be sticking to the older associative array method of creating my structures. That way they are easily transferred as a Flex object.

A while ago a colleague and I were working on a timesheet application in Flex. The idea was that you could commit a custom timebar object, generated in flex, and it would update the dataset in the back end using the ColdFusion flex gateway.

I came across the code recently, and decided to tidy it up a bit, and make the query dynamic, based on the Struct contents. The obvious limitation to this is that your Struct and your database schema have to match exactly.

I won't go into the Flex application here, but I've emulated its input arguments here with a pre-populated structure.

Notice that this code also calls the CFC object at the end. The data itself isn't massively important, it's a time object for recording tasks.

Next we have the function, which accepts a Struct() argument called 'taskStruct'. I then loop through the structure, and populate a SQL query using the keys from a collection. The only logic is a check to see if it is the last structure element, as this controls the ',' placement.

That will insert your Struct into a database, in small and tidy manner. It was somewhere around here that we started using cfproperty tags, and creating strongly typed objects for Flex.

Below is the full code in one run for the PhoneBook AIR application.

As our application starts I want to fire the request for data, so we call an init() method on initialization. Also I have turned the flex chrome off here with 'showFlexChrome="false"'.

The init() method calls an event listener that controls the window movement (Drag and drop) and makes a call to getData().

The moveListener() method adds a listener to the outerCanvas element which forms the application 'border'. When this event is fired it calls moveWindow.

The getData() function calls the webservice, and specifies which method to call.

The moveWindow function also contains a check to see if the datagrid was the event target, as this was interfering with the functionality of the Datagrid. It would be interesting to see if anyone else has a more elegant solution to this, rather than a specific element check.

To populate our datagrid we need to use a data provider. In FLEX applications I usually use the RemoteObject function, but for AIR I've been using the WebService tag.

The final two 'chrome' functions we need are the minimize and close functions. I will detail handling custom chrome in another article.

Our WebService is referencing two functions. A results handler and a fault handler.

The resultsHandler() simply assigns the datagrids dataprovider as the result of the WebService call. By adding DataGridColumn's to the datagrid with the right naming convention our results from the returned query object will map directly to our datagrid.

The faultHandler() function simply Alerts a user to a fault event.

Lastly I have a function that assigns the image source dynamically based on the click event in the datagrid.

So that completes the Phone Book AIR application. There are one or two tweaks I'd like to make in the image handling, but otherwise its exactly the spec I had in mind.

You can view the full code here.