It's easiest to show examples The not-yet-PR for the maven-dependency-plugin uses these templates:
https://github.com/coyotesong/maven-dependency-plugin/tree/convert-tree-dot-to-velocity/src/main/resources/templates and more importantly the format-specific content in the 'macros' directory. It uses the two new Directives I'm proposing. (The other proposal still needs a lot of work.) - indent: https://github.com/coyotesong/maven-dependency-plugin/blob/convert-tree-dot-to-velocity/src/main/java/org/apache/maven/plugins/dependency/utils/velocity/runtime/directive/Indent.java - collapse: https://github.com/coyotesong/maven-dependency-plugin/blob/convert-tree-dot-to-velocity/src/main/java/org/apache/maven/plugins/dependency/utils/velocity/runtime/directive/Collapse.java REAL WORLD EXAMPLES (maven-dependency-plugin PR): YAML #macro (showChildDependencies $parent) #for ($child in $parent.children index $idx) #indent #showNestingDependencies($child, $idx, $parent.children.size) #end #end #end #macro (showNestingDependencies $dependency) #set ($artifact = $dependency.artifact) #indent - groupId: $artifact.groupId artifactId: $artifact.artifactId version: $artifact.version type: $artifact.type #if ($dependency.hasScope) scope: $artifact.scope #end #if ($artifact.hasClassifier) classifier: $artifact.classifier #end optional: $dependency.optional #if ($dependency.hasChildren) children: #showChildDependencies($dependency) #end #end #end The double indentation isn't required - it's proper YAML if either one is dropped, but I feel the double indentation is a little easier to read. Since that's the primary reason I use YAML (vs. JSON, etc.) that's a big win. JSON is similar but a bit more gnarly since it requires '[', ']', and commas on everything but the final item and that means a lot of extra *#if* directives. GRAPHML #** * This is expanded for clarity *# #macro (showSimpleDependency $dependency) #collapse <node id="$dependency.id"> <data key="d0"> <y:ShapeNode> <y:NodeLabel>$dependency.nodeString</y:NodeLabel> </y:ShapeNode> </data> </node> #end #end #** * This is expanded for clarity *# #macro (showSimpleEdge $parent $child) #collapse <edge source="$parent.id" target="$child.id"> <data key="d1"> <y:PolyLineEdge> <y:EdgeLabel>$child.artifact.scope</y:EdgeLabel> </y:PolyLineEdge> </data> </edge> #end #end In this case the format don't *require* what *#collapse* does, but it makes it much easier for the developer since they can use the open format shown above yet have it collapsed to a single line in the final document. This can substantially reduce the size of the document. The user can still use the single-line version if they want... but I suspect most people would prefer the latter since it makes it easy to have one variable (mostly) per line. I will probably combine these examples with a POC. JSON doesn't care about whitespace and it's not common to have everything but any children on a single line. Proper indentation is still useful since it gives the user information about the level of nesting. It will require tweaking the current *#if directives* *used to handle the lack of a final comma and the addition of the [ ] delimiters for the children.* Bear On Mon, Apr 7, 2025 at 1:28 AM Claude Brisson <cla...@renegat.net.invalid> wrote: > The use case you give is also not clear to me. > > What does `writeNodeAsJson()` do on arrays or maps if you still have to > call `walktree()` on children? Where is the final ']' or '}' written? > > Usually, I do solve such problems of displaying a tree using an extra > `$indentation` argument which is just passed to the recursive macro with > additional spaces and it's sufficient (and frankly, this is most easily > done in Java rather in VTL where it's not exactly pertinent...). > > > On 07/04/2025 00:58, Nathan Bubna wrote: > > A PR to look over would be good. > > > > On Sun, Apr 6, 2025 at 9:41 AM Bear Giles <bgi...@coyotesong.com> wrote: > > > >> I've been working on a contribution to maven-dependency-plugin and > spent a > >> fair amount of time trying to figure out how to cleanly implement proper > >> indentation when converting the dependency tree to json, yaml, etc. > >> > >> After a bit of pain, okay a lot of pain, I have finally implemented a > new > >> Directive - 'indent' - which extends Block and prepends a 'padding' > value > >> on render(). This works since render() is also called recursively. > >> > >> (I know there's a TreeContext but I have no idea how to use it, whether > it > >> can be used within the existing plugin, or even if it would help solve > this > >> problem.) > >> > >> An example of how it is used is: > >> > >> #macro (writeNodeAsJson $node) > >> // do the json magic > >> #end > >> > >> #macro (walktree $node) > >> #indent > >> #writeNodeAsJson($node) > >> #foreach ($child in $node.children) > >> #walktree ($node) > >> #end > >> #end > >> #end > >> > >> (I don't have that code on this system so there may be a slight error in > >> it.) > >> > >> At the moment the directive doesn't take any parameter but I do plan to > add > >> an optional one, ideally either a string literal or a reference, but I > >> haven't coded it yet. In theory it could even be a reference to a > different > >> macro, e.g., so you could have 'I", "II",... then 'a','b'..., then > >> '1','2'... since the macro could be provided the current indentation > depth > >> but I'll leave that for another day. > >> > >> I think I have JIRA access and if so I'll create an issue and submit a > PR. > >> > >> Bear Giles > >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@velocity.apache.org > For additional commands, e-mail: dev-h...@velocity.apache.org > >
