Complex filter in Loop XPath query in tExtractJSONField

nfz11 — Thu, 02 May 2019 22:11:20 GMT

Hi, I am able to do simple filtering in the Loop XPath query in a tExtractJsonField component. For example, if my input JSON string is:

[
 {
   "snack": {
       "name": "Apple",
        "id": 1,
        "type": "Fruit"
   }
 },
 {
   "snack": {
       "name": "Orange",
       "id": 2,
       "type": "Fruit"
   }
 },
 {
   "snack": {
       "name": "Broccoli",
       "id": 3,
       "type": "Vegetable"
   }
 }
]

I can use this Loop XPath query with a simple filter to return only the fruit snacks:

"/snack[type="Fruit"]"

I want to do something a little more complex. I want to select the Apple if the count of vegetables is <=1, else I want to select the Orange. I tried adding more complex xpath using the count() function but could not get it to work:

"/snack[type="Fruit" and (
(name ="Apple" and count(/snack/type="Vegetable") <= 1) or 
(name ="Orange" and count(/snack/type="Vegetable") > 1))]"

Are these more complex filters even supported in Talend?

Thanks in advance for any help.

Re: Complex filter in Loop XPath query in tExtractJSONField

nfz11 — Thu, 02 May 2019 23:11:45 GMT

I figured it out. You can use complex filters like the one I describe. The exact syntax would be:

"/snack[type="Fruit"][
(name ="Apple" and count(//type[text()='Vegetable']) <= 1) or 
(name ="Orange" and count(//type[text()='Vegetable']) > 1)]"

topic Complex filter in Loop XPath query in tExtractJSONField in Talend Studio

Complex filter in Loop XPath query in tExtractJSONField

Re: Complex filter in Loop XPath query in tExtractJSONField