transfer

Transfer the execution of the script to a different SWML section, URL, or RELAY application. Once the transfer is complete, the script will continue executing SWML from the new location.

Properties

Valid Destination Values

The destination string can be one of:

• "section_name" - section in the current document to execute. (For example: execute: main)
• "relay:<relay application>" - relay application to notify (currently not implemented)
• "https://example.com/sub-swml.yaml" - URL pointing to the document to execute. An HTTP POST request will be sent to the URL. Authentication can also be set in the url in the format of username:password@url. The params object is passed, along with the variables and the Call object.

Examples

Basic transfer to a URL

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version: 1.0.0
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sections:
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  main:
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    - transfer:
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        dest: "https://example.com/next"

Basic transfer to a section

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version: 1.0.0
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sections:
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  main:
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    - play:
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        url: 'say:Transferring you to another section'
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    - transfer:
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        dest: subsection
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    - play:
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        url: 'say:Back!'
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  subsection:
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    - play:
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        url: 'say:inside a subsection'

Named parameter with sub-parameters

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version: 1.0.0
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sections:
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  main:
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    - transfer:
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        - dest: "https://example.com/next"
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        - params:
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            - foo: "bar"

Transfer to a SWML script hosted on a server

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version: 1.0.0
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sections:
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  main:
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    - prompt:
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        play: >-
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          say: Press 1 to be transfered to the Sales department, 2 for marketing
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          department or anything else to listen to some music.
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    - switch:
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        variable: prompt_value
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        case:
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          '1':
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            - transfer:
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                dest: 'https://<YOUR_NGROK_UUID>.ngrok-free.app'
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                params:
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                  where: sales
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          '2':
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            - transfer:
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                dest: 'https://<YOUR_NGROK_UUID>.ngrok-free.app'
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                params:
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                  where: marketing
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    - play:
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        url: 'https://cdn.signalwire.com/swml/April_Kisses.mp3'

A minimal server for this SWML script can be written as follows:

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from flask import Flask, request
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from waitress import serve
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app = Flask(__name__)
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@app.route("/", methods=['POST'])
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def swml():
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    content = request.get_json(silent=True)
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    print(content)
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    return '''
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version: 1.0.0
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sections:
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  main:
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    - answer: {}
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    - play:
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        url: 'say: Welcome to the {} department.'
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'''.format(content['params']['where'])
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if __name__ == "__main__":
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    serve(app, host='0.0.0.0', port=6000)

This server (running on localhost) can be made accessible to the wider web (and thus this SWML script) using forwarding tools like ngrok. Visit ngrok.com to learn how.

The server will be sent the payload in the following format:

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{
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  "call": {
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    "call_id": "<call_id>",
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    "node_id": "<node_id>",
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    "segment_id": "<segment_id>",
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    "call_state": "answered",
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    "direction": "inbound",
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    "type": "phone",
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    "from": "<address>",
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    "to": "<address>",
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    "from_number": "<address>",
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    "to_number": "<address>",
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    "headers": [],
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    "project_id": "<your Project UUID>",
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    "space_id": "<your Space UUID>"
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  },
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  "vars": {
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    "answer_result": "success",
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    "prompt_result": "match_digits",
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    "prompt_value_raw": "2",
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    "prompt_value": "2"
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  },
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  "params": { "where": "marketing" }
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}

The call object is described in detail in the introduction. All variables created within the SWML document are passed inside vars, and the params object contains the parameters defined in the params parameter of transfer.