api.py 文件源码

def perform_service_call(service_name):
    """
    POST /api/<version>/service/<service_name>

    POST to a service to change it somehow. service_name may be a path.

    For example, to start an environmental recipe in an environment, use the
    start_recipe service:

        POST /api/<version>/service/<environment_id>/start_recipe {"recipe_id": <id>}
    """
    # Add leading slash to service_name. ROS qualifies all services with a
    # leading slash.
    service_name = '/' + service_name
    # Find the class that ROS autogenerates from srv files that is associated
    # with this service.
    try:
        ServiceClass = rosservice.get_service_class_by_name(service_name)
    except rosservice.ROSServiceException as e:
        return error(e)
    # If we made it this far, the service exists.
    # Wait for service to be ready before attempting to use it.
    try:
        rospy.wait_for_service(service_name, 1)
    except rospy.ROSException as e:
        raise socket.error()
    # Get JSON args if they exist. If they don't, treat as if empty array
    # was passed.
    json = request.get_json(silent=True)
    args = json if json else []
    service_proxy = rospy.ServiceProxy(service_name, ServiceClass)
    try:
        # Unpack the list of args and pass to service_proxy function.
        res = service_proxy(*args)
    except (rospy.ServiceException, TypeError) as e:
        return error(e)
    status_code = 200 if getattr(res, "success", True) else 400
    data = {k: getattr(res, k) for k in res.__slots__}
    return jsonify(data), status_code