Question

I am pretty new to flex, specially to mxml part. There are some confusing things for me.
For example I have custom component file Abc.mxml with code:

<s:Group>
   //Lots of code
   <s:Button id="someId" /*code*/ />
</s:Group>

And then I have Xyz.mxml which is also custom component file.

<s:Group>
  <fx:Scrip>
     //something happens here, for example some other button click or whatever
  </fx:Script>
  //code
  <comp:Abc />
</s:Group> 

So question is how do I access that button’s properties. I want when something happens in Xyz file, button’s (someId) visibility to become false. If Abc.mxml was AS class file then it would be easy, just make object etc., but how to get if it’s mxml file, I have no idea.

Answer 1

There’s no big difference between mxml and as. When you write Xyz.mxml:

<s:Group>
  <fx:Scrip>
     //something happens here, for example some other button click or whatever
  </fx:Script>
  //code
  <comp:Abc />
</s:Group>

…you just specify class Xyz derived from Group. Mxml – is just markup language which makes building interfaces easier. During compiling mxml files are transformed to pure AS, so there’s nothing (on a large scale) you can do in mxml which you can’t in AS and vice-versa.

ID property in mxml is similar to instance name in AS, i.e. it will be converted to public property in your calss.

Answer to your question.

You can write public function in Abc and call it in Xyz.

Abc.mxml:

<s:Group>
    <fx:Script>
        <![CDATA[
            public function doSomething():void
            {
                someId.enabled = false;
            }
        ]]>
    </fx:Script>
   <s:Button id="someId"/>
</s:Group>

Xyz.mxml:

<s:Group>
  <fx:Script>
      <![CDATA[
         private function somethingHappened():void
         {
             abcComponent.doSomething();
         }
      ]]>
  </fx:Script>
  //code
  <comp:Abc id="abcComponent"/>
</s:Group>

In somethingHappened function you can access Button abcComponent.someId directrly, but I strongly reccommend not to do this, since it breaks encapsulation and makes your classes more cohesive (and so on).