Hi David,
I definitely understand your confusion about the tree-datapath thing.
It's about because "tree" resp. actually "basetree" tries to be
super-smart, but it fails obviously. If you take a look at
"basetree#createChildTrees()", you'll see a for-in loop which copies an
internal object called "_instanceAttrs" into a new js-Object. All
instance attributes of an instance are stored in this "_instanceAttrs"
field, plus some special objects like a datapath (, if it was defined
per datapath-tag!). And now we copy this field, because we want to make
sure that every tree-node/leaf has got the same method, handlers,
appearance etc. when we dynamically instantiate new trees-leafs.
Now comes the fun part: You've given your tree a datapath per tag,
therefore the "_instanceAttrs"-object contains an entry called
"$datapath". Later on in "basetree#createChildTrees()", the copy of
"_instanceAttrs" (with the "$datapath" entry) will get another datapath,
but this time attribute-like (identifier is "datapath" instead of
"$datapath"). So, two datapaths for a tree => makes double replication,
just as noted in the bugreport.
- André
On 12/5/2007 9:24 PM, David Buckler wrote:
Andre
I appreciate you opening up that bug and I understand it will definitely cover the datapath attribute versus child node issue. I am just wondering does the datapath of the second tree get set by the first tree by the instantiation, and hence causes the duplicate replicaton. I am just confused because all I did to get the duplicate replication was move the datapath attribute out of the tree tag into a child datapath tag with an xpath of *.
David
-----Original Message-----
From: André Bargull [mailto:[EMAIL PROTECTED]
Sent: Tuesday, December 04, 2007 4:05 PM
To: David Buckler
Cc: Henry Minsky
Subject: Re: [Laszlo-user] Dataset as an Attribute and Tag Error
I've created LPP-5193 (http://www.openlaszlo.org/jira/browse/LPP-5193)
to fix this issue.
- André
On 12/4/2007 11:00 PM, André Bargull wrote:
Hello David,
I could reproduce this bug, so feel free to open a bugreport.
Here is an example using the tree code that is in the Laszlo Reference.
You will note that all I did was pull the datapath attribute out of
the last tree node and used it as a tag. When you run this code it creates
duplicate nodes exactly as I first experienced. Let me know if you are
experiencing the same behavior I am and I have no problems opening up
a bug for this.
<canvas width="450" height="250">
<include href="lz/tree.lzx"/>
<dataset name="ancestors">
<hobbit name="Frodo">
<hobbit name="Drogo">
<hobbit name="Fosco" grandparent="true"/>
<hobbit name="Bolger, Ruby" grandparent="true"/>
</hobbit>
<hobbit name="Brandybuck, Primula">
<hobbit name="Brandybuck, Gorbadoc" grandparent="true"/>
<hobbit name="Took, Mirabella" grandparent="true"/>
</hobbit>
</hobbit>
</dataset>
<!-- data replicated tree -->
<view width="200" height="200">
<tree datapath="ancestors:/" icon="null" showroot="false">
<tree icon="null" text="$path{'@name'}"
isleaf="$path{'@grandparent'}">
<datapath xpath="*"/>
</tree>
</tree>
</view>
</canvas>
