Extracting Data

Many workflows do not just drive a UI — they read from it. The Extract action reads a value from a UI element and stores it under a named key. That key is then available as {output.key} in every subsequent step, condition, and expression.

Extract a Single Value

- intent: read the current filename
  action:
    type: Extract
    key: filename
    scope: save_dialog
    selector: ">> [role='combo box'][name='File name:'] >> [role=edit]"
    attribute: text
  expect:
    type: EvalCondition
    expr: "output.filename != ''"

Use EvalCondition as expect to verify the extraction actually produced something. Always would succeed even if the element was empty or the selector matched nothing meaningful.

Attribute Types

Attribute	Reads
text (default)	The ValuePattern text, falling back to the Name property. Use for edit fields and value-bearing controls.
name	The UIA Name property — the element's accessible label or caption.
inner_text	Direct children's names joined by newlines. Useful for composite controls like list items or tooltips where the meaningful content lives in child elements.

Extract, Compute, Reuse

The real power of extraction is what you can do with the value once you have it. A common pattern: read a value from the UI, compute a derived value, then use it to drive a subsequent action.

Here is a concrete example: a Save As dialog shows a default filename. The workflow needs to prepend an output directory — without knowing the filename in advance.

anchors:
  save_dialog:
    type: Session
    selector: "[name='Save As']"

phases:
  - name: save_to_output_dir
    mount: [save_dialog]
    steps:
      - intent: extract the default file name before saving
        action:
          type: Extract
          key: saved_file
          scope: save_dialog
          selector: ">> [role='combo box'][name='File name:'] >> [role=edit]"
          attribute: text
        expect:
          type: EvalCondition
          expr: "output.saved_file != ''"

      - intent: compute full save path
        action:
          type: Eval
          key: full_path
          expr: "param.output_dir + output.saved_file"
        expect:
          type: Always

      - intent: set full path in file name field
        action:
          type: SetValue
          scope: save_dialog
          selector: ">> [role='combo box'][name='File name:'] >> [role=edit]"
          value: "{output.full_path}"
        expect:
          type: ElementHasText
          scope: save_dialog
          selector: ">> [role='combo box'][name='File name:'] >> [role=edit]"
          pattern:
            contains: "{output.full_path}"

Three steps: extract the default name, build the full path with Eval, write it back with SetValue. The expect on the final step verifies the field actually contains the computed value before the workflow proceeds.

Extract Multiple Values

Set multiple: true to extract all matching elements. The values are stored as a list under the key.

- intent: extract all row labels from the results table
  action:
    type: Extract
    key: row_labels
    scope: results_panel
    selector: ">> [role=list item]"
    attribute: name
    multiple: true
  expect:
    type: EvalCondition
    expr: "output_count('row_labels') > 0"

Returning Values as Workflow Outputs

When the workflow is used as a subflow, only keys declared in outputs: are returned to the caller. Keys not listed are workflow-local.

outputs:
  - name: saved_file
  - name: full_path

See Parameters and Outputs for the full declaration syntax.