The if node

Simple if-then-else logic.

Note: If you want to filter data-items from a stream of data, use the where node.

Almost everything you can do with this node, can also be done with an eval node, using the if function.

Example

|json_emitter()
.json(
      '{"address": "", "value": 99}',
      '{"address": "cond_scale", "value": 94}',
      '{"address": "cond_robot", "value": 95}'
      )
.as('data') 

|if(lambda: "data.address" == '')
.then('address is empty')
.else(lambda: str_concat('address is {{"data.address"}} and value is ', string("data.value")))
.as('data.note')

The if node adds a new field data.note with either the string 'address is empty' or, if the address is not empty, a string with the address and the value of the field data.value.

If we would remove the else parameter in the example, every data-item for which the if test returns false, would not get the field data.note added (and simply left untouched on emit).

Parameters

Parameter	Description	Default
[node] test( lambda )	if test lambda
then( any )	value when test evaluates as TRUE, any type including a lambda expression is valid
else( any )	value when test evaluates as FALSE, any type including a lambda expression is valid	undefined
as (string)	field-path for the output value