I am currently working on my own BPMN modeler, but I was getting a problem when importing an existing BPMN file without the bpmndi:BPMNDiagram part.
For example my input would be something like:
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" >
<process id="Process_1" isExecutable="false">
<startEvent id="StartEvent_1" />
<endEvent id="EndEvent_191tx7z" />
But since the xml does not contain the bpmndi:BPMNDiagram part, my modeler could not render the file.
Is there any other API I could look into to solve my problem? Like auto generating a set of coordinates.
By the way, I can use bpmn-moddle to parse the xml to a Moddle tree, so the problem would also be converting a moddle tree to a renderable full xml.