Forward Funlet

This Twilio Function is based on the Twimlet of the same name.

It can be used as a drop-in replacement for the Twimlet, by using the URL of the Twilio Function as a webhook with the same GET parameters.

Alternatively, it can be customized by setting properties in the environment. GET and POST parameters are considered first, if provided, then environment properties, then config properties declared in the script.

Environment properties are most convenient when you are using a single instance of this script in your account. To customize multiple instances, the recommended way is to modify the script parameters in the config object, directly in the script.

Stages

The Forward Funlet has two stages:

Stage	Addressing	Description
1	Caller	Check that caller is allowed and forward the call
2	Caller	After a failed call, redirect to fallback URL, if any

These two stages would typically be implemented in two separate Twilio Functions. In the Forward Funlet, they are running in two separate instances of the same Twilio Function. This is in line with the original Forward Twimlet, which implemented both stages in the same script.

Input

Phone Number

Text string, the forwarding number.

1. Event: PhoneNumber parameter
2. Environment: FUNLET_FORWARD_PHONE_NUMBER environment property
3. Script: phoneNumber config property

Caller ID

Text string, one of the verified phone numbers of your account that you want to appear as caller ID for the forwarded call.

1. Event: CallerId parameter
2. Environment: FUNLET_FORWARD_CALLER_ID environment property
3. Script: callerId config property

Fallback Url

Text string, fallback URL where further instructions are requested when the forwarding call fails.

1. Event: FailUrl parameter
2. Environment: FUNLET_FORWARD_FALLBACK_URL environment property
3. Script: fallbackUrl config property

Timeout

Number, duration in seconds to let the call ring before the recipient picks up.

1. Event: Timeout parameter
2. Environment: FUNLET_FORWARD_TIMEOUT environment property
3. Script: timeout config property

Allowed Callers

A list of text strings with the only phone numbers of callers that will be allowed to be forwarded.

1. Event: a single AllowedCallers= or a list of AllowedCallers[]= parameters
2. Environment: up to five allowed callers, each in a separate environment property:

• FUNLET_FORWARD_ALLOWED_CALLER1,
• FUNLET_FORWARD_ALLOWED_CALLER2,
• FUNLET_FORWARD_ALLOWED_CALLER3,
• FUNLET_FORWARD_ALLOWED_CALLER4,
• FUNLET_FORWARD_ALLOWED_CALLER5

3. Script: allowedCallers config property with an array of string values

Access Restricted Error Message

Text string, a recording URL or a text to say when the calling number is not one of the allowed callers configured.

1. Event: AccessRestricted
2. Environment: FUNLET_FORWARD_ACCESS_RESTRICTED environment property
3. Script: accessRestricted config property

Language

Text string, language code for text messages, e.g. 'en' or 'en-gb'. Defaults to 'en': English with an American accent.

1. Event: Language parameter
2. Environment: FUNLET_FORWARD_LANGUAGE environment property
3. Script: language config property

Voice

Text string, voice for text messages, one of 'man', 'woman' or 'alice'. Defaults to 'alice', who speaks in a large selection languages.

1. Event: Voice parameter
2. Environment: FUNLET_FORWARD_VOICE environment property
3. Script: voice config property

Caller

Text string, the caller's phone number.

1. Event: From or Caller property provided by the Twilio Voice event

Phone Number Called

Text string, the Twilio phone number called for the forwarding.

1. Event: To or Called property provided by the Twilio Voice event

Dial Done (Stage 2)

Boolean, a flag set to true to bypass the first stage of processing when returning from the call to the forwarding number.

1. Event: Dial parameter

Call Status (Stage 2)

Text string, the status of the forwarding call.

1. Event: DialCallStatus or DialStatus property provided by <Dial>

Output

This Twilio Function returns TwiML instructions for Twilio Voice.