This library contains a set of classes and functions for performing common operations using the WVA Web Services API. It contains both general web services helpers (using the Python requests library) as well as more specific helpers.
In addition, packaged with the library is a command-line utility using the API that serves as both an example of how the library may be used as well as a convenient tool for developer use.
The library may be installed using pip by doing the following:
pip install wva
This will install both the library and command-line application.
Help for the CLI application can be obtained by running the
application with the --help option. This will show the available
commands:
$ wva --help
Usage: wva [OPTIONS] COMMAND [ARGS]...
Command-line interface for interacting with a WVA device
Options:
--https / --no-https Use HTTPS instead of HTTP
--hostname TEXT Force use of the specified hostname
--username TEXT Force use of the specified username
--password TEXT Force use of the specified password
--config-dir TEXT Directory containing wva configuration files
--help Show this message and exit.
Commands:
cliconfig View and clear CLI config
delete DELETE the specified URI Example: $ wva get...
get Perform an HTTP GET of the provided URI The...
post POST file data to a specific URI Note that...
put PUT file data to a specific URI Example: $...
subscriptions View and Edit subscriptions
vehicle Vehicle Data Commands
You can get help for a specific command by specifying --help after
the command. For instance,
$ wva subscriptions --help
Usage: wva subscriptions [OPTIONS] COMMAND [ARGS]...
View and Edit subscriptions
Options:
--help Show this message and exit.
Commands:
add Add a subscription with a given short_name...
clear Remove all registered subscriptions Example:...
delete Delete a specific subscription by short name
graph Present a live graph of the incoming...
list List short name of all current subscriptions
listen Output the contents of the WVA event stream...
show Show metadata for a specific subscription...
The first time you attempt to talk to a device, you will need
to provide credentials for talking to the device. The CLI
application will then store those credentials in the file
~/.wva/config.json and attempt to use those credentials in
the future. If the credentials are ever invalid, you will
be prompted to enter the credentials again.
You can clear the credentials that are stored by deleting the wva configuration or by running the following command:
$ wva cliconfig clear
See the Full API documentation for full details on the API and its usage. Here's some examples:
from wva import WVA
wva = WVA("<ip>", "user", "password")
# clear any existing subscriptions
for sub in wva.get_subscriptions():
sub.delete()
# add subscriptions for some pieces of vehicle data
wva.get_subscription("speed").create("vehicle/data/VehicleSpeed", interval=3)
wva.get_subscription("rpm").create("vehicle/data/EngineSpeed", interval=5)
# receive vehicle data and print it
def data_received(data):
print("<- {}".format(data))
es = wva.get_event_stream()
es.add_event_listner(data_received)
es.enable()from wva import WVA
from wva.exceptions import WVAHttpServiceUnavailableError
wva = WVA("<ip>", "user", "password")
# print out all available data elements and whether
# they currently have data or not
for name, element in wva.get_vehicle_data_elements().items():
try:
curval = element.sample()
except WVAHttpServiceUnavailableError:
print("{} (Unavailable)".format(name))
else:
print("{} = {} at {}".format(name, curval.value, curval.timestamp.ctime()))from wva import WVA
wva = WVA("<ip>", "user", "password")
client = wva.get_http_client()
# write a hello.py file to the python filesystem
client.put("/files/userfs/WEB/python/hello.py".format(relpath), "print 'Hello, World!'\n")
# print the contents of hello.py on the target to the screen
print(client.get("/files/userfs/WEB/python/hello.py"))
# delete hello.py
client.delete("/files/userfs/WEB/python/hello.py")Contributions to the project are very welcome. Please submit any issues you find on the github issue tracker. If you have a change you would like to have included in the library, please submit a pull request.
Information for developers on coding style, how to run the tests, etc. may be found in the Developer's README.
This library is in "Alpha" currently and is not tested beyond the unit tests included in the code and basic developer testing. Prior to a 1.0 release, the APIs may change in backwards incompatible ways at each minor revision.
If you run into issues, please create an issue on the project's Github Page.
This software is open-source. Copyright (c), Digi International Inc., 2015.
This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, you can obtain one at http://mozilla.org/MPL/2.0/.
Digi, Digi International, the Digi logo, the Digi website, and Digi Device Cloud are trademarks or registered trademarks of Digi International, Inc. in the United States and other countries worldwide. All other trademarks are the property of their respective owners.
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