Solved

Using the same function with different extended object types

Posted on 2011-03-07
2
206 Views
Last Modified: 2012-05-11
Hi still being very green with Actionscript, I wonder if you could help with the following,

For the sake of an example think of a page in a book where,

I have 4 seperate classes,  ParagraphData, PartHeadingData, FooterData and ListData each which extend from the PageItemData class, a pageItem being its namesake on a page and each class has a different set of extended properties

Each "page of the book" as such is presented in an array called pageData and contains for example 3 instances of ParagraphData, 1 PartHeadingData , 1 list etc
 
What I need to do is iterate over the pageData array and act accordingly depending on what object type is currently being examined.

I have tried the following but with no success.

for each (var pageItem:PageItemData in pageData){
                        
      //check for prefix span and add if true            
                        if (pageItem.has_Prefix_Span && pageItem.prefix_Span_Text!==""){
                              createParagraphPrefixSpan(pageItem,pElem)
                        }
                              
      //check for inline graphic      
                        if ((pageItem.paragraph_Contains_Figure)as ParagraphData){
                        pElem=figure.checkForFigure(pageItem,pElem,figureData);
                        }

The first portion works because of the properties within the PageItemData class which are common to all , but the second does not ,even if I try to cast to the correct datatype, the compiler keeps complaining about


1118: Implicit coercion of a value with static type vo:PageItemData to a possibly unrelated type vo:ParagraphData

1119: Access of possibly undefined property paragraph_Contains_Figure through a reference with static type vo:PageItemData

I know I could replace the first line with

for each (var pageItem:* in pageData){

but this seems odd to me seing as all the items being iterated over are extended from the type shown.

What am I missing here and thanks in advance

John


}
0
Comment
Question by:BloodGrinder
2 Comments
 
LVL 20

Accepted Solution

by:
ChristoferDutz earned 500 total points
ID: 35056986
Well I'd to some checks the following way:
if(pageItem is ParagraphData) {
   var paragraphData:ParagraphData = ParagraphData(pageItem);

   ... work with paragraphData ...

} 

Open in new window


In the if-part you check if the type is the one you expect.
If it is I tend to define a local varialbe containing a casted reference to the type I did my check for. This makes working with it a lot easier.

By the way ... I wouldn't write "!==" ... I think you are looking for "!=" (Actually I don't know what !== actually does think it's a check for instance equality)
0
 

Author Closing Comment

by:BloodGrinder
ID: 35113072
Apologies I thought i had closed this 3 days ago
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
playing flash video on kiosk at startup 6 406
free flash maker 5 206
Adobe flash player fails to install 12 302
How to add jQuery and JavaScript(s) into Dreamweaver? 1 247
There are times in your Flash CS4 application when you want more than a simple pointer or a hand, and it's hard to find an ideal walk-through to tell you what to do.  I spent a few days recently learning my way around making custom cursors in Flash,…
I have been doing hardcore actionscripting for some time; and needless to say I have faced a lot of problems in just understanding others' code rather than understanding what the code executes. A programmer's life can become hell when there are a lo…
In this tutorial viewers will learn how to create a basic shape tween animation in Flash including shape hints for smooth animation Open a new document in Flash: Draw a shape: Select another frame (how long you want the tween to be): Right click and…
The goal of the tutorial is to teach the user how to live broadcast using Flash Media Live Encoder and connecting it to YouTube to broadcast. Log into your Youtube account, choose live stream settings, start live stream from Flash Media Live Enc…

911 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now