Eclipse Community Forums: Sapphire » What is the best way to add tree node for an optional xml child element?

Help

Home

Home » Archived » Sapphire » What is the best way to add tree node for an optional xml child element?

Show: Today's Messages :: Show Polls :: Message Navigator

What is the best way to add tree node for an optional xml child element? [message #1494834]

Mon, 01 December 2014 20:07

Slava Kabanovich

Messages: 8
Registered: December 2014

Junior Member

Consider xml:

<my-node>
  <my-optional-child required-attribute="x">
     <my-optional-grandchild required-attribute="y"/>
  </my-optional-child>
</my-node>

Element <my-optional-child> is optional in <my-node> and element <my-optional-grandchild> is optional in <my-optional-child>. Once one or both of these elements are present, attribute 'required-attribute' must be set.

In interface MyNode I added ImpliedElementProperty PROP_MY_OPTIONAL_CHILD.
In editor definition (.sdef file) I described node as

	<node>
		<id>MyOptionalChildNode</id>
		<property>MyOptionalChild</property>
...
       </node>

and included it to children of MyNode tree node.
The same approach is implemented for my-optional-grandchild.

Editor works fine when child nodes are available in xml. When I remove them, nodes in tree remain, which is ok as a handle to add the child element just by editing its form.
What is bad, is that when there are no child elements in xml, nodes in tree and forms display a validation error about missing required attribute.

The node in xml can be hidden by
<visible-when>${RequiredAttribute != null}</visible-when>
Then everything is ok but one: I do not have the handle to add the child element.

I tried to add a form section to parent node as such a handle. But again, it displays a validation error when the child element is missing.

What is the best practice to treat this case?

Report message to a moderator

Re: What is the best way to add tree node for an optional xml child element? [message #1495870 is a reply to message #1494834]

Tue, 02 December 2014 15:37

Konstantin Komissarchik

Messages: 1077
Registered: July 2009

Senior Member

Based on the semantics you have described, an implied element property isn't the best choice. You should use a regular element property, then in sdef you add the associated node using the node factory construct, just like you would for a list property.

Report message to a moderator

Re: What is the best way to add tree node for an optional xml child element? [message #1497288 is a reply to message #1495870]

Wed, 03 December 2014 18:05

Slava Kabanovich

Messages: 8
Registered: December 2014

Junior Member

Thank you very much, it works just as I like it.

I wonder, why my previous attempts to implement it this way failed. I really tried node factory for a non-list property before, but always got definition errors, and finally decided that node factory is only for list properties. I cannot remember what I did wrong, maybe I failed to use <case> element, which could seem redundant due to lack of choice.

Report message to a moderator