How to proceed if I want to have my custom XML source model?

[atejshee-tibco]

I need the GLSP to render nodes and/or transitions based on a custom XML model (consider a simple example XML model mentioned ahead).

<?xml version="1.0" encoding="UTF-8"?>
<university>
    <name>XYZ University</name>
    <class id="10000">
        <classname>Literature</classname>
        <student id="12345">
                <properties>
                    <property name="student_name" value="John">
                    <property name="age" value="25">
                </properties>
        </student>
        ......
        ......
        <student id="56789">
                <properties>
                    <property name="student_name" value="Bob">
                    <property name="age" value="24">
                </properties>
        </student>
    </class>
</university>

With this custom XML as the source model, I want to create a diagram that would depict these details in the form of nodes (as shown in the picture ahead).

I want to modify the existing node-json-theia example as node-xml-theia, which will take this custom XML as the source model.

I read the documentation which suggests the steps, however, how to proceed/begin with it, if I want to create the gmodel from this custom XML?
Would the interpretation of this XML model to GLSP understandable model be same as it is for the JSON model, or does it need to be handled in some other way?

Would really appreciate any help/pointers on this.

[tortmayr]

Hi @atejshee-tibco,

If you want to use an XML file as source model for your GLSP language you have to implement a custom SourceModelStorage¹.
The implementation² used in node-json-theia example directly serializes the runtime JS model to a JSON file

So in your case instead of a SourceModelStorage implementation that is based on the AbstractJsonModelStorage you need to implement your own. There a many JS packages available that allow direct parsing and conversion to XML e.g. Xml2js³
In you custom implementation you then provide the logic for reading the XML file, converting it to a JS object(loadSourceModel) and storing it in the ModelState. You also need to implement the reverse logic for seralizing back from the JS model in the ModelState to the XML file (saveSourceModel).

Then simply configure your SourceModelStorage in the diagram module.
This is the only customization you need to make. The interpretation of the XML model stored in the ModelState can then be used by GLSP same as the pure JSON model.

Footnotes

1. https://eclipse.dev/glsp/documentation/sourcemodel/#source-model-storage-and-model-state ↩

2. https://github.com/eclipse-glsp/glsp-examples/blob/master/project-templates/node-json-theia/tasklist-glsp-server/src/model/tasklist-storage.ts ↩

3. https://www.npmjs.com/package/xml2js ↩