Vic on Flex
Thursday - December 13, 2007
DataServiceTransaction & LCDS
Just a quick blog note on something that I've now wasted a good day on twice, only because I never blogged it last time. The challenge is say you need to make changes to data in a database, maybe across multiple tables, and using DataServices just doesn't make sense. For example, cloning x number of records. It's easy enough to create your Java remote objects and call them from Flex, but then in an FDS/LCDS implementation how do you push those changes out to Flex clients?
There's some documentation on this, scattered vaguely across the web, and there's a good chance that perhaps this has already been blogged - but I just couldn't find it. The trick is that there are 2 sides to this story, one, you must perform your operations on the database directly, and then two, you must INFORM FDS that changes have occurred. So say I want to create a new Author record, this is what that might look like:
public void createAuthor(){
DataServiceTransaction dtx = DataServiceTransaction.begin(false);
//create record and save:
Author auth = new Author();
auth.setFirstName("Ernest");
auth.setLastName("Hemingway");
AuthorDAO dao = new AuthorDAO();
dao.create(auth);
//let LCDS know:
dtx.createItem("author", auth);
dtx.commit();
} So I just do my regular db insert, then I use a DataServiceTransaction to let FDS know that I've created an Item. Alternatively, I could use this approach:public void createFDSItem(){
DataServiceTransaction dtx = DataServiceTransaction.begin(false);
Author auth = new Author();
auth.setFirstName("victor");
auth.setLastName("javarubba");
AuthorDAO dao = new AuthorDAO();
dao.create(auth);
dtx.refreshFill("author", null);
dtx.commit();
} This approach might be a bit of overkill and might be better suited when doing mass updates across many records. I did a little bit of testing and it seemed that for the most part calling CreateItem() was faster that the refreshFill() in pushing the new record to the Flex Client.What cost me so much grief is that I was falsely led down the garden path to believe that calling dtx.createItem("author", auth) would not only inform FDS but also actually create the item. This is not the case. There! Officially blogged!
Tuesday - November 13, 2007
Losing the RollOverColor in TileList
In one of our projects we have a custom effect that plays over each tile as a user mouses over the items in a tilelist. Not getting too much into details, I basically overlay a canvas that appears and disappears as the mouse moves over the tile, giving the illusion that each tile sort of explodes. So the one thing I don't need is the rollOverColor effect, which defaults to a nasty baby blue. Usually I just set the rollOverColor to the same color as the background but that's not working so well on this project, since the background can be an assortment of wallpapers.
Unfortunately there doesn't seem to be any way to disable the rollOverColor, and maybe someone can shed some light on an easier solution. I ended up extending TileList with my own mxml component and overriding the drawitem function, as follows:
<?xml version="1.0" encoding="utf-8"?>
<mx:TileList xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.controls.listClasses.IListItemRenderer;
protected override function drawItem(item:IListItemRenderer,
selected:Boolean = false,
highlighted:Boolean = false,
caret:Boolean = false,
transition:Boolean = false):void{
super.drawItem(item,false,false,caret,transition)
}
]]>
</mx:Script>
</mx:TileList>
As you can see, I override the selected and highlighted parameters with false, thereby eliminating the selected and roll over effect. Seems to work quite well. I now use this mxml component instead of TileList throughout my applications.
Friday - November 09, 2007
Where or where has my intellisense gone?
I'm working on a flex 3 app using the latest flexbuilder 3 beta, both the plugin and standalone versions. For some reason, in some mxml files my intellisense just seems to not work at all. While in other mxml files the intellisense works fine. Turns out that in this latest beta release, Flexbuilder gets cranky if you use double quotations in Metadata Event tags:
[Event("forward", type="mx.events.Event")] will kill your intellisense and your control clicks. You will feel very lonely.
[Event('forward', type='mx.events.Event')] will make everything right again, blue coding skies ahead.
On a side note, the single quote is actually only necessary on the type attribute, intellisense seems to work fine if you use double quotes on the Event name itself.
Hopefully this will be fixed in the next release.
Thursday - November 01, 2007
Using floating IFrames in Flex 3 Beta: wmode buh-bye?
Just a quick one today... we're porting some work to Flex 3 where we do the floating Iframe thing, and noticed some strange behaviour changes. In Firefox, the floating Iframe would briefly flash into view and then disappear, while in IE the Iframe would appear, however if we clicked into the IFrame embedded html page and then clicked outside it somewhere on the flex app, the IFrame would disappear from view.
Took a little bit of sniffing around but in the end the culprit was the html-template\index.template.html file. For some reason, and it might well be a very good reason, the property wmode is no longer included in the flash player tags ("wmode", "opaque" in AC_FL_RunContent() && wmode="opaque" in <EMBED>) in FlexBuilder 3. Once we added those back in, the floating IFrame started working again.
Thursday - October 25, 2007
Not another Flex, AmfPHP, Cairngorm CodeGen! MAKE IT STOP!
Haven't blogged in quite some time and this is a project that's been half done for far too long. Like everyone else we decided to build our own code generator, just something fairly straightforward that would generate all the DAO code, the Cairngorm code, and a nice little interface to test all the main CRUD and DAD functions we have come to know and love. Lately we've been busy souping up the generated UI, not so much in terms of style... beauty does not live here... functionality however does.
You can get all the gory details by clicking on this link:
http://www.crazedcoders.com/php/codegen.php
We built this code to use AMFPHP, Cairngorm, PHP and Flex 2.01. We've put in place validators, datepickers, checkboxes and textinputs on our forms and generated full Command/Event/Model/Controller classes. We've implemented binding on the generated view form fields. Our code generator will detect relationships between tables and render comboboxes accordingly, for example, if there's a foreign key on a customer table linked to a country table, the customer view will have a combobox linked to the model.countries collection. But I must stop, I'm getting too technical...
Basically, if the generator runs successfully, you're a few clicks away from being able to manage the data in your database from Flex. The generated code is zipped up for you to download. Inside the zip you will find a complete and ready to import Flexbuilder Project and the php packages ready to copy into your amfphp services folder. Further details can be found by clicking on the link.
