CODEWITHSUNDEEP
cytoscape.js
Tim
Tim

Reputation: 424

Cytoscape ignore "can not create edge with nonexistant target"

I would like to ignore the error that is returned by cytoscape when attempting to create an edge that points to an unexisting target.

For technical reasons, I can not make sure my edges are pointing to an existing targets.

If I directly pass

elements: myListOfEdgesAndNodes

When declaring the cy object, it fails and doesn't display anything because of that error. I have thought of a workaround, which would be to initialize cy object with my nodes

elements: myListOfNodes

And then dynamically add edges in a loop with cy.add() in which case I believe the add will fail when the edge's target is non-existant, but it should not prevent other nodes/edges from being displayed. Does that sound like a good workaround ? Is there anything better to do ?

Upvotes: 0

Views: 1437

Answers (1)

cubic lettuce
cubic lettuce

Reputation: 6549

If you have the final elements array in your python scope, then you can easily filter out all those edges which point to a non-existing vertex. Here is an example, which assumes the following typical scenario (as described in the docs of the cytoscape-dash):

  1. all vertices have an explicit "id" field and no "source" field
  2. all edges have "source" and "target" fields
def removeDanglingEdges(elements):
    vids = set([v['data']['id'] for v in elements if not 'source' in v['data']])
    return [e for e in elements if not 'source' in e['data'] or (e['data']['source'] in vids and e['data']['target'] in vids)]

# example usage
elements = [{'data':{'id':1}},{'data':{'source':1,'target':3}},{'data':{'id':3}},{'data':{'source':1,'target':6}}]
cleaned_elements = removeDanglingEdges(elements)
print(cleaned_elements) # -> [{'data':{'id':1}},{'data':{'source':1,'target':3}},{'data':{'id':3}}]

Upvotes: 1

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