Dynamic vars with tasks

[hans-d]

Allow vars/envs to be dynamic with output from another task, not just shell commands.

vars:
   BLAH:
      task: :some:other:task
   FOO:
      sh: echo {{.BLAH}} | grep x
   BAR:
      task: :yet:some:other:task
      var:
         TARGET: '{{.FOO}}'

[mgbowman]

Any chance we could triage this issue? I could really use this feature and would like to try and implement it.

[victor-ufg]

I also ran into this, I actually tried this first because it kind of felt "natural", to only find out in the docs it isn't supported :/

Also, I find that the "workaround" (running sh: task some:other:task) is tricky to execute well when you're including the task in another Taskfile (you end up having to make the tasks "public" rather than internal, and knowing the included Taskfile namespace).

[trulede]

You can do this

version: '3'

tasks:
  default:
    cmds:
      - cmd: echo "FOO_ENVAR=foo" > tdotenv
      - task: dotenv
  dotenv:
    dotenv: [tdotenv]
    cmds: 
      - cmd: echo "  var FOO_ENVAR = $FOO_ENVAR"

I think it covers most use cases. You can also simply source files (on Linux), and use multiline cmds to collect/redirect/consolidate ouput.

[victor-ufg]

While I agree about moving state around "manually" is possible, I think it would really improve ergonomics to have an out of the box experience.

It would be nice to be able reuse blocks of the Taskfile by just referencing them, it makes it quite more understandable IMHO (especially if you're providing scripts for not so knoweldgeable Taskfile users).

[trulede]

Using a dotenv file is actually the best way. Its simple and easy to understand. Also, its a common and normal pattern (see GitHub workflows).

If you put it into the internal logic of Task ... then you can look over the many many issues that get opened because ... its not at all simple to keep everyone happy.

There is a PR #2711 which adds some new function, and #997 is more or less the same issue as raised here (where people want values injected in the task var space) so I will close this as a duplicate of that. It can then be discussed if its really necessary.