NO FOR LOOPS with e4x! Well, hardly ever anyway. You access serach on
attributes like this:
var xlFound:XMLList = myXML.property.(@name=="username"); //*all e4x
expressions return an xmllist*
var xmlFound:XML = xlFound[0]; //if we know there wil be only one node
found, get it
trace([EMAIL PROTECTED]); //will show 'me'
Note, if you are filtering on an attribute value, and not all nodes have
that attribute, you will get an error with the above syntax. To avoid
that I always use this form:
var xlFound:XMLList = myXML.property.(attribute("name")=="username");
//*all e4x expressions return an xmllist*
That format also lends itself to dynamic expressions, since "name" or
whatever can be a variable containing the attribute name.
Tracy
________________________________
From: [email protected] [mailto:[EMAIL PROTECTED] On
Behalf Of Nayan Savla
Sent: Tuesday, March 04, 2008 2:36 PM
To: [email protected]
Subject: Re: [flexcoders] extracting items from array collection
getItemAt doesn't work
Tracy,
I see your point in using e4x expressions and the performance hit i
take just to use dynamic nested structure. It won't take much for me
to convert my code to make use of e4x functionality.
I have started doing that and i couldn't find a way to search and
match attributes, for eg.
<property name="username" value="me"/>
<property name="account_status" value="active"/>
<property name="session_id" value="h5142ner7vq5oitqcvi0"/>
<property name="salt" value="e9d6b14092524122254"/>
<property name="signup_date" value="2007-08-16"/>
<property name="now" value="2008-03-04"/>
<property name="first_name" value="Nayan"/>
how do i retrieve the value attribute associated with the attribute
name="username" ?
I know i could always run a for loop and then store the data as
name-value pairs in an object but i want to know if there is a way
doing it using the xmllist class.
testList.property.(@name == "account_status")[EMAIL PROTECTED]
something like this, it will be really helpful since something like
this would be the beginning.
thanks for all your help.
Nayan
On Mon, Mar 3, 2008 at 7:12 PM, Tracy Spratt <[EMAIL PROTECTED]
<mailto:tspratt%40lariatinc.com> > wrote:
>
>
>
>
>
>
>
>
>
> As I suspected, you are not using xml:
>
> "I haven't set the resultformat of my httpservice, its
> using the default format."
>
>
>
> The default resultFormat is to have Flex convert your XML into a
nested
> dynamic object structure. This converts XMLLists into arrays, among
other
> things.
>
>
>
> Generally this is bad. There is no benefit to a nested dynamic
structure
> over XML and in fact, there are many reasons to use XML, e4x
expressions
> being chief among those reasons. Your current situation is actually
the
> worst of both worlds: you lose the e4x functionality and suffer from
the
> performance hits of non-strongly-typed data access.
>
>
>
> The only reason to stay on this course is laziness.
>
>
>
> If you absolutely insist, I will tell you how to get a ArrayCollection
out
> of the mess you have, but it would be a mistake. Two better options
are:
>
> * Use XMLListCollection
>
> * Use e4x and convert your XMLList into an ArrayCollection of strongly
typed
> data objects. This is a manual process of looping over the XMLList and
> building each object and then adding it to the ArrayCollection
>
>
>
>
>
> Tracy
>
>
>
> ________________________________
>
>
> From: [email protected] <mailto:flexcoders%40yahoogroups.com>
[mailto:[email protected] <mailto:flexcoders%40yahoogroups.com>
] On
> Behalf Of Nayan Savla
> Sent: Monday, March 03, 2008 7:11 PM
> To: [email protected] <mailto:flexcoders%40yahoogroups.com>
> Subject: Re: [flexcoders] extracting items from array collection
getItemAt
> doesn't work
>
>
>
>
>
>
> the url parameter for the httpService is a XML file so yes,
>
> var bigCollection:ArrayCollection = data.result.myBigList as
> ArrayCollection; //I am reading an xml file.
>
> this is true. I haven't set the resultformat of my httpservice, its
> using the default format.
>
> Also in the debugger i see that the variable bigCollection stores the
> xml file as a object list and as i mentioned i can easily extract the
> array from this using,
>
> var smallCollection:Array = bigCollection.toArray().slice(0,10);
> //this works just fine.
>
> the data in this array is as expected, What i don't understand is why
> i can't convert it into an ArrayCollection.
>
> Nayan
>
> On Mon, Mar 3, 2008 at 3:39 PM, Tracy Spratt <[EMAIL PROTECTED]
<mailto:tspratt%40lariatinc.com> > wrote:
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Have you verified this line below? It raises doubts:
> >
> >
> > var bigCollection:ArrayCollection = data.result.myBigList as
> > ArrayCollection; //I am reading an xml file.
> >
> >
> >
> > First, XML will only yield an XMLList and you cannot cast an XMLList
to
> an
> > ArrayCollection.
> >
> >
> >
> > I suspect you may not have xml as you think, but instead a nested
object
> > structure. It depends on how you are getting your data. If that is
so, it
> > is not a good way to do it. Have you set your resultFormat="e4x"?
> >
> >
> >
> > If you are getting XML from the server, why not use
XMLListCollection?
> >
> >
> >
> > If you do not want to use that, you should convert your XMLList into
an
> > ArrayCollection of strongly typed data objects. This is a manual
process
> of
> > looping over the XMLList and building each object and then adding it
to
> the
> > AC.
> >
> >
> >
> > Tracy
> >
> >
> >
> > ________________________________
> >
> >
> > From: [email protected]
<mailto:flexcoders%40yahoogroups.com>
[mailto:[email protected] <mailto:flexcoders%40yahoogroups.com>
] On
> > Behalf Of Nayan Savla
> > Sent: Monday, March 03, 2008 4:00 PM
> > To: [email protected] <mailto:flexcoders%40yahoogroups.com>
> > Subject: [flexcoders] extracting items from array collection
getItemAt
> > doesn't work
> >
> >
> >
> >
> >
> >
> >
> > Hi All,
> >
> > I am trying to get data from an ArrayCollection and i tried various
> > things without any luck.
> >
> > this is the code,
> >
> > var bigCollection:ArrayCollection = data.result.myBigList as
> > ArrayCollection; //I am reading an xml file.
> >
> > 1) var smallCollection:ArrayCollection =
> > bigCollection.getItemAt(0,10); //i believe this is the correct
method
> > but doesn't work
> >
> > 2) var smallCollection:ArrayCollection =
> > bigCollection.toArray().slice(0,10) as ArrayCollection; //this
returns
> > null
> >
> > 3) var smallCollection:Array = bigCollection.toArray().slice(0,10);
> > //this works just fine.
> >
> > any ideas why i can't just use the second statement, please ignore
my
> > knowledge of flex if i am missing something fundamental.
> >
> > thanks
> > Nayan
> >
> >
>
>
