File change

Goal

Run a workflow whenever a particular file in your project changes. Time: 10 minutes.

schema: 1
name: On config change
id: on-config-change
folder: ~/src/acme-apis
triggers:
  enabled: true
  selected: file
  file:
    path: config/app.json     # relative to `folder`; must be inside it
    debounce_ms: 1500
blocks:
  - id: changed
    kind: code
    language: python
    uses: [trigger.path, trigger.received_at]
    body: |
      import json, os
      t = json.load(open(os.environ["TERMORQ_INPUT"], encoding="utf-8"))["trigger"]
      print(json.dumps({"line": f"{t['path']} changed at {t['received_at']}"}))
    outputs:
      type: object
      properties:
        line: { type: string }

Rules

Termorq watches inside the workflow folder, and refuses a path outside it.
Changes are debounced (by 1.5 seconds by default), so a burst of saves starts one run.
path matches the changed file’s path relative to the folder (or a trailing part of it). If you leave path empty, any change in the folder triggers a run.
The trigger provides trigger.path and trigger.received_at.

Warning

Don’t write files into the watched folder from the same workflow, or each run will trigger the next one. Write artifacts to $TERMORQ_OUTPUT instead.

Check your run

Run touch ~/src/acme-apis/config/app.json. One run starts, and line names the file.

Exercise

Make the block validate that the changed file is still valid JSON, and publish valid: boolean.

Details

import json, os
t = json.load(open(os.environ["TERMORQ_INPUT"], encoding="utf-8"))["trigger"]
p = os.path.join(os.environ["TERMORQ_FOLDER"], "config", "app.json")
try:
    json.load(open(p, encoding="utf-8")); ok = True
except Exception:
    ok = False
print(json.dumps({"valid": ok}))