[Nifi] - Multiple predicate in recordpath filter

Question

Hello all,

I'd like to use the updateRecord processor to create some fields in my JSON. But I'd like to use some conditions to do that. In the recordpath documentation, I can see that there is a "filter" capability, which works like this: /field[filter]/path, but as far as I can see it's not possible to have multiple conditions in this filter. I'd like to do something like:

if (field1 == A or field1 == B) {

field2 = C

} else if (field1 == D and field1 != E) {
field2 = G
}

The example is silly but this is to give you the idea. By the way, except using a script, I don't know how to do that, except may be extracting the fields, put it as attribute and play with expression language but this would mean working with single-record flows and I don't want to do that.

Any idea?

Thanks for your suggestions

Stéphane

justenji · Accepted Answer

@stephane_davy
Sorry I couldn't work on this further last week. Now my solution looks like this.

JSON from GenerateFlowFile

[
      {
         "myfield": "JustForHavingJson",
         "myfield1": "A"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": "B"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": "C"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": "D"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": "E"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": "X"
      },
      {
         "myfield": "JustForHavingJson",
         "myfield1": ""
      }
   ]

Definitions of ControllerServices and AvroSchemaRegistry
ControllerServices and AvroSchemaRegistry
Flow
Flow

Details of RecordProcessing-Processors
Details RecordProcessing-Processors

Result FF-Content after MergeRecord:

{"myfield":"JustForHavingJson","myfield1":"A","myfield2":"C"}
{"myfield":"JustForHavingJson","myfield1":"B","myfield2":"C"}
{"myfield":"JustForHavingJson","myfield1":"C","myfield2":""}
{"myfield":"JustForHavingJson","myfield1":"E","myfield2":""}
{"myfield":"JustForHavingJson","myfield1":"X","myfield2":""}
{"myfield":"JustForHavingJson","myfield1":"","myfield2":""}
{"myfield":"JustForHavingJson","myfield1":"D","myfield2":"G"}

Personally I wouldn't do a MergeRecord at the end but go on with the three single connections of the UpdateRecord processors.

Do you think this could be a possible solution or have you found a better way to do this?