Bloblang: variables and mappings

[illotum]

Is there a way to pass variables to mappings?

Trying something like this says the variable is not defined:

let value = some.value
let hashedValue = $value.hash("hmac_sha1", $secret)
map mask {
    root = this
    messyField = messyField.replace($value, $hashedValue)
}
objects = objects.map_each(o -> o.apply("mask"))

[Jeffail]

Hey @illotum, variables aren't automatically passed through to mappings, right now the only work around is to pass an object literal to the map that aggregates the target value as well as the variables that you want, so something like this:

let value = some.value
let hashedValue = $value.hash("hmac_sha1", $secret)

map mask {
    root = this.target
    root.messyField = this.target.messyField.replace(this.value, this.hashedValue)
}

objects = objects.map_each(o -> {
  "target": o,
  "value": $value,
  "hashedValue": $hashedValue,
}.apply("mask"))

Eventually I want to add argument definitions for maps that would make this a bit tidier, we could also consider adding variable capture as part of that.

[Joshswooft]

+1 on supporting this feature