Shadow Variables
VoiceXML uses standard variable systems. This means that Fuse does too, because it is built on VoiceXML. Standard variable systems allow users to create their own variables and manipulate them directly.
Fuse allow access to global session variables that contains information about the current call. The session variable is a complex object that contains properties. Sometimes those properties have properties of their own.
Because these variables are global variables, there will be no need to use the
$
notation to access them.In Fuse, users might want to access the following session properties:
Global Variable | Explanation |
session.connection.ani | Caller's number, the phone number where the call was made from |
session.connection.dnis | Dialed number for this call. This is useful for applications that have multiple number deployments and would need to identify which number the caller has dialed. |
session.connection.callee_type | |
session.id | Unique ID for this call |
session.name | Name of the current active Fuse application |
session.connection.protocol.sip.headers | only for SIP-in calls |
When collecting input or interacting with a REST web service, information often exists in addition to the “response” data that users may want to access. Shadow variables allow users to access this additional data.
Adding a
$
symbol to the end of a variable, automatically creates a shadow variable for that variable. The shadow variable will contain different member variables depending on the type of input or web service it is being used with. For example, with an input credit_card
you can determine the confidence of the grammar engine match by accessing credit_card$.confidence
.This variable is filled in the case of both a match or a nomatch.
Lastresult$
allows users to get the list of all possible matches, not just the best match. In the event that speech input exists for the variable in use, lastresult$
can also provide a recording of the utterance spoken by the user (for speech input).Having access to this data, even in the “nomatch” case, allows users to send DTMF input off without requiring a match, or to send the utterance recording somewhere (perhaps to transcription).
Users can also access the “n-best” results if there were multiple matches by accessing
$lastresult[i]
where “i” represents the position in the list of matches (0 is the best match, 1 is second best, etc.).lastresult$.confidence
lastresult$.utterance
lastresult$.inputmode
lastresult$.interpretation
lastresult$.recording
(only for speech input)lastresult$.length
lastresult$[i].confidence
lastresult$[i].utterance
lastresult$[i].inputmode
lastresult$[i].interpretation
Some modules in Fuse have specific shadow variable associated with them.
“name” below refers to the actual name of the module.
name$.duration
For
input modules, a standard set of shadow variables exist (https://www.w3.org/TR/voicexml20/#dml2.3.1):
name$.utterance
name$.inputmode
name$.interpretation
name$.confidence
For the
Record module, a slightly different set of shadow variables exist (https://www.w3.org/TR/voicexml20/#dml2.3.6):
name$.duration
name$.size
name$.termchar
name$.maxtime
name$.http_code
name$.headers
(object indexed by header name)name$.raw_headers
(0-indexed array containing all header strings)name$.error
(only in the event of an error)
NOTE: Some of the following terms and concepts are specific to Google Dialogflow.
Shadow variable | Returns |
---|---|
name$.query | string
End-user input received by Dialogflow. |
name$.intent | string
Intent matched to the received end-user input. |
name$.message | string
Text of the response spoken or displayed to the end-user based on the matched intent. |
name$.entities | object
Entity types associated with the matched intent. |
name$.confidence | integer
Confidence level for the name field. |
name$.allRequiredParamsPresent | boolean
Returns true when:
OR
Returns false when:
AND
|
Table data returned by a
DynamoDB module is formatted in a zero-indexed array, which you can access through shadow variables. You can write these shadow variables by using the names of any column(s) returned and the module itself. The
$
symbol is not used here.Format:
module_name[index_number].[column_name]
Example:
CallerQuery[0].product_id
Last modified 1yr ago