ArangoDB：处理遍历中的悬空边缘

Question

I am using ArangoDB 2.8 and arangojs.

For some reasons, I've got dangling edges (I can not change that) in my data. In a traversal complex expander function, I am looking for a specific document, before pushing it in the connected data structure of the expander:

var refDoc = someColl.document(obj1[someProp]);

connected.push( edge:theEdge, vertex: refDoc });

How can I avoid the traversal expander being stopped by the error raised by someColl.document() if the searched document does not exist ?

I've tried without success to use Node-style callbacks. Should I try (how?) to add es6-promise or bluebird on the modules on the server ?

Thank you.

Answer 1

As Mike Williamson already sugested, try {} catch are the way to go:

const arangodb = require('@arangodb');

try {
 var refDoc = someColl.document(obj1[someProp]);
 connected.push( edge:theEdge, vertex: refDoc });
}
catch (ex) {
  if ((ex not instanceof ArangoError) or
      (ex.errorNum !== arangodb.ERROR_ARANGO_DOCUMENT_NOT_FOUND)) {
    throw(ex)
  }
}

So you can ignore the document not found error, but continue throwing other (maybe more fatal) errors.