Google Forms Safe Form Edit with Write Control

arazzo: 1.0.1
info:
  title: Google Forms Safe Form Edit with Write Control
  summary: Read a form's current revision, apply a batch update guarded by that revision, and confirm the new revision.
  description: >-
    A form that several people or jobs can edit needs optimistic concurrency, and
    the Forms API provides it through write control. This workflow reads the
    form to capture its current revision id, applies the requested item and
    settings changes in a batch update that declares that revision as required,
    and reads the form back to confirm the revision moved. If another writer
    changed the form between the read and the write, the update is rejected
    rather than silently overwriting their work. Every step spells out its
    request inline so the flow can be read and executed without opening the
    underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: googleFormsApi
  url: ../openapi/google-forms-api.yaml
  type: openapi
workflows:
- workflowId: safe-form-edit
  summary: Edit a form without clobbering a concurrent writer, using revision-guarded write control.
  description: >-
    Reads the current revision id, retitles the form and updates one existing
    item under that revision guard, then confirms the resulting revision id.
  inputs:
    type: object
    required:
    - formId
    - newTitle
    - itemIndex
    - itemTitle
    properties:
      formId:
        type: string
        description: The id of the form to edit.
      newTitle:
        type: string
        description: The new title to apply to the form.
      itemIndex:
        type: integer
        description: The zero-based index of the existing item to update.
      itemTitle:
        type: string
        description: The new title for the item at itemIndex.
      itemRequired:
        type: boolean
        description: Whether the question at itemIndex must be answered.
        default: true
  steps:
  - stepId: readCurrentRevision
    description: >-
      Read the form to capture the revision id the edit will be based on, along
      with the current items so the caller can confirm itemIndex points at the
      item they mean to change.
    operationId: getForm
    parameters:
    - name: formId
      in: path
      value: $inputs.formId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      revisionId: $response.body#/revisionId
      items: $response.body#/items
      currentTitle: $response.body#/info/title
  - stepId: applyGuardedUpdate
    description: >-
      Apply the title change and the item change in one batch update, declaring
      the revision read above as required. The service rejects the batch if the
      form has moved on, which is the concurrency guarantee this flow exists for.
    operationId: batchUpdateForm
    parameters:
    - name: formId
      in: path
      value: $inputs.formId
    requestBody:
      contentType: application/json
      payload:
        includeFormInResponse: true
        writeControl:
          requiredRevisionId: $steps.readCurrentRevision.outputs.revisionId
        requests:
        - updateFormInfo:
            info:
              title: $inputs.newTitle
            updateMask: title
        - updateItem:
            item:
              title: $inputs.itemTitle
              questionItem:
                question:
                  required: $inputs.itemRequired
            location:
              index: $inputs.itemIndex
            updateMask: title,questionItem.question.required
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      targetRevisionId: $response.body#/writeControl/targetRevisionId
      updatedForm: $response.body#/form
  - stepId: confirmRevision
    description: >-
      Read the form back to confirm the applied title and to capture the new
      revision id to carry into the next edit.
    operationId: getForm
    parameters:
    - name: formId
      in: path
      value: $inputs.formId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      revisionId: $response.body#/revisionId
      title: $response.body#/info/title
  outputs:
    priorRevisionId: $steps.readCurrentRevision.outputs.revisionId
    revisionId: $steps.confirmRevision.outputs.revisionId
    title: $steps.confirmRevision.outputs.title