Feedback Mechanism; Feedback Expressions - Cisco TelePresence DX70 Reference Manual

Cisco TelePresence DX70 and DX80
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Introduction

Feedback mechanism

To build solutions that can reliably keep the state between
your application and the codec synchronized, you can set up
a notification system to report the changes in the state of the
codec.
The API supports notifications on the following:
• Configuration changes
• Status changes
• Event notifications
These notifications will not be sent unless you have explicitly
told the codec to do so. You can subscribe to the feedback
by registering feedback expressions. How you register
feedback expressions varies according to the connection
method used.
When using HTTP, the method of handling feedback differs
slightly from what is presented in this section. See the
"Feedback from codec over HTTP" on page 35
information.
WARNING: A codec may give very much feedback,
especially when calls are connected and disconnected.
Do only subscribe to the feedback you need.
Never register for all status feedback by issuing
xFeedback register /Status. This may give the control
application too much data to handle, which may lead to
sluggish or unpredictable behavior.
D15363.05 Cisco TelePresence DX70 and DX80 API Reference Guide CE9.2, NOVEMBER 2017.
About the API About the API xConfiguration

Feedback expressions

The expression used when registering for feedback is a
variant of the XPath language. The XPath language describes
a way to select nodes from an XML/JSON document. The CE
software contains three main feedback documents.
Document
Status
Configuration
Event
The syntax for feedback registering is:
xFeedback register <path>
Never register for all status feedback by issuing xFeedback
for more
register /Status.
It is safe to register for all configuration changes using
xFeedback register /Configuration,
changes will most likely not occur that often.
By going through some examples, we can see how this
information can be used to build feedback expressions. A
good way to verify the expressions is to point your browser
to http://<ip-address>/getxml?location=path
xgetxml <path>
matches the nodes you want feedback on.
xCommand
API command Path
xStatus /Status
xConfiguration /Configuration
xEvent /Event
as configuration
or to execute
from the terminal, and check that the output
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API Reference Guide
xStatus
Example 1: Microphones Mute status.
Terminal query
xStatus Audio Microphones Mute
*s Audio Microphones Mute: Off
** end
Equivalent feedback expression
xFeedback register /Status/Audio/Microphones/Mute
Example 2: Name of all video input connectors.
Terminal query
xConfiguration Video Input Connector Name
*c xConfiguration Video Input Connector 1 Name:
"NameA"
*c xConfiguration Video Input Connector 2 Name:
"NameB"
*c xConfiguration Video Input Connector 3 Name:
"NameC"
*c xConfiguration Video Input Connector 4 Name:
"NameD"
*c xConfiguration Video Input Connector 5 Name:
"NameE"
** end
Equivalent feedback expression
xFeedback register /Configuration/Video/Input/
Connector/Name
Example 3: Name of video input connector 3.
Terminal query
xConfiguration Video Input Connector 3 Name
*c xConfiguration Video Input Connector 3 Name:
"NameC"
** end
Equivalent feedback expression
xFeedback register /Configuration/Video/Input/
Connector[@item='3']/Name
Copyright © 2017 Cisco Systems, Inc. All rights reserved.
Appendices