can arangoDB aql skip filters by condition?

Question

i work for a bbs app recently, and when i use the aql, i got a problem, for example:

//params:.com/t/123?&digest=true
=>
  FOR t IN threads
    FILTER t.digest == true && some conditions
    RETURN t

and the result is as expected,but when the parameter 'digest' is undefined or false, i want it returns all the threads..not which 'digest' = false, so i have to use if...else to write two almost same code, just remove the condition 't.digest == true' for example:

if(params.digest) {
  return `digest == true && conditions`
} 
return `conditions`

i'm using javascript, please give me a direction...

Answer 1

You can use the function HAS(document, attributeName) to check whether the attribute is present in the document.

FOR t IN threads
  FILTER (!HAS(t,"digest") || i.digest == true) && conditions
  RETURN t