Kevin Flynn wrote:
> Hussein said:
>
>
>>I don't want to show off but what you need to do can be done much simply
>>by using the full power of XPath.
>
>
> You can show off as much as you like - I need all the help I can get :)
>
> I've noticed that nobody else seems to need much help writing macros. I
> don't know whether this indicates that:
>
> - nobody else is writing complex macros, or
> - lots of people are writing them, but they are all smarter than me.
>
> It seems to me that that the threshold for writing macros is quite high: the
> mechanisms for handling conditions and passing parameters are unusual, and
> even when using the console functionality, you don't get a lot of feedback.
> I do a fair amount of XSL coding, but even so I don't find it easy using the
> XPath functionality in XXE.
>
> I'm not proposing any changes to the macro functionality - I know that there
> are a lot of performance-related constraints involved, and I'm sure a lot of
> effort has gone into it. But it occurs to me that if there are other macro
> writers out there, then it might be an idea to pool our experience in the
> form of some kind of "macro library" containing useful snippets and examples
> of macro code.
>
> To start the ball rolling, here is a "traverse" macro that will visit all of
> an element's descendant nodes. To use it you need to:
>
> - define a view namespace on the root configuration element by adding:
>
> xmlns:view="http://www.xmlmind.com/xmleditor/namespace/scope/view";
> - define two variables in the namespace ($view:current and
> $view:original)
> and set them both to point to the element whose subtree you want to
> traverse
> - insert code where indicated to perform the required action on each
> visited node.
>
> <command name="traverse">
> <macro>
> <sequence>
> <!-- an action performed on $view:current here will be performed on
> every node-->
> <choice>
> <sequence>
> <match context="$view:current" pattern="node()[child::node()]"/>
> <set context="$view:current" expression="./child::node()[1]"
> variable="view:current"></set>
> <command name="traverse"/>
> </sequence>
> <sequence>
> <!-- an action performed on $view:current here will only be
> performed on every 'leaf' node-->
> <choice>
> <sequence>
> <match context="$view:current"
> pattern="node()[following-sibling::node()]"/>
> <set context="$view:current"
> expression="./following-sibling::node()[1]" variable="view:current"></set>
> <command name="traverse"/>
> </sequence>
> <sequence>
> <test context="$view:current"
> expression="not(parent::node()=$view:original)"/>
> <choice>
> <sequence>
> <match context="$view:current/parent::node()"
> pattern="node()[following-sibling::node()]"/>
> <set context="$view:current/parent::node()"
> expression="./following-sibling::node()[1]" variable="view:current"></set>
> <command name="traverse"/>
> </sequence>
> </choice>
> </sequence>
> </choice>
> </sequence>
> </choice>
> </sequence>
> </macro>
> </command>
>
> I haven't tested it very thoroughly, but it seems to work so far. Any
> corrections/suggestions/improvements gratefully received.
Nobody is writing macros and you are clearly very smart (not kidding here).
*We*, XMLmind, are writing macros and this is sufficient to have
invented them and to document them (in case they may be useful for other
XXE users).
*Macros are not intended to be complex.* That's the key point. If a
macro seems to be complex to write then it needs to be coded as a native
Java command.
That is, the most typical macro is clearly:
---
<command name="convertToBold">
<macro>
<sequence>
<command name="convert"
parameter="[implicitElement] emphasis" />
<command name="putAttribute" parameter="role bold" />
</sequence>
</macro>
</command>
---
> Today's mail from Graham Heath suggests that there is some interest out
> there. It shouldn't be too hard to make a simple "search attributes" macro
> that would fill the gap until 3.0 comes along. Anybody want to do that?
If XXE lacks native commands to implement this macro-command, just tell
us...
