Support custom rendering of specific elements with plugin

[canton7]

I'm evaluating StrictDoc for use within my company, and one of the pieces we're missing is the ability to create various custom traceability / coverage tables, embedded into documents (along with other content).

My ideal end result would be:

• Create a custom element in the document grammar, e.g. TRACE_TABLE.
• When editing this element, the CONTENT contains an e.g. YAML description of the trace table I want: parent doc, child doc, any intermediate docs, fields to show, etc etc.
• When rendering the document (HTML, PDF, etc), this is replaced by the rendered traceability table(s).

The sorts of tables we need can be quite custom, and it wouldn't make sense to bake their logic into StrictDoc itself.

Therefore, a nice approach might be to use the existing plugin architecture. I was imagining something like either:

• The plugin is called once with the TraceabilityIndex, and can make edits to individual SDocNodes, or:
• The plugin is called once for each SDocNode / SDocNodeField, is passed the TraceabilityIndex and that SDocNode, and can return a replacement SDocNode / SDocNodeField to render.

In both of these cases, the plugin would be able to locate and parse my custom elements, and transform the content into whatever ReST I want to render.

Do you think this would be a viable approach which you would be prepared to accept? I'd be happy to implement it.

Thanks!

[canton7]

As a little proof-of-concept, this money-patch does roughly what I want, at least for HTML and PDF export from server:

def transform_node(
    traceability_index: TraceabilityIndex, node: SDocNode, content_field: SDocNodeField
) -> SDocNodeField:
    if node.node_type == "TRACETABLE":
        return SDocNodeField.create_from_string(node, content_field.field_name, "EDITED", True)
    return content_field


def install_node_transform_patch(
    callback: Callable[[TraceabilityIndex, SDocNode, SDocNodeField], SDocNodeField]
) -> None:
    original = MarkupRenderer.render_node_field

    def render_node_field(
        self, document_type: DocumentType, node_field: SDocNodeField
    ) -> Markup:
        node = node_field.parent
        if node is not None and node_field == node.get_content_field():
            node_field = callback(self.traceability_index, node, node_field)

        return original(self, document_type, node_field)
        
    
    setattr(MarkupRenderer, "render_node_field", render_node_field)


def main() -> None:
    install_node_transform_patch(transform_node)

    # Defer import so the patch is installed before command execution starts.
    from strictdoc.cli.main import _main

    _main()


if __name__ == "__main__":
    main()