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I'm trying to send a message to the websocket server on my FME Cloud instance. I can successfully transmit the following:

 

{"ws_op" : "send","ws_msg" : "hello"}

 

But I want to send a JSON message as "ws_msg", so I tried:

 

{"ws_op" : "send","ws_msg" : fme_get_attribute("payload")}

 

Which isn't received on the other end, similarly to if we have an incorrect message, i.e. without the "send message"-format from the documentation of the WebSocketSender. I would guess it's something with the quotes around the message, but I am unable to escape quotes in the message formatting window.

 

So, how can I send a JSON message (Payload-attribute attached) to a websocket using FME?

 

{
      "type": "Feature",
      "properties": {
       "icon-image": "pulsing-dot-blue"},
      "geometry": {
        "type": "Point",
        "coordinates":  
          17.3016102,
          59.6615453
        ]
      }
    }

 

Using a JSON Templater works, in combination with this line:

 

{ ws_op: 'send', ws_msg: '@Value(Dummy)' }

 

JSON Templater creates an attribute into Dummy, which is then processed. But how does '@Value(Dummy)' differ from fme_get_attribute("payload")? 

Using a JSON Templater works, in combination with this line:

 

{ ws_op: 'send', ws_msg: '@Value(Dummy)' }

 

JSON Templater creates an attribute into Dummy, which is then processed. But how does '@Value(Dummy)' differ from fme_get_attribute("payload")? 

fme_get_attribute automatically escapes " to \"  which isn't done by the @Value command. In a JSONTemplater you can also use fme:get-json-attribute("yourAttributeName") to explicitly load insert valid JSON values.

fme_get_attribute automatically escapes " to \\" which isn't done by the @Value command. In a JSONTemplater you can also use fme:get-json-attribute("yourAttributeName") to explicitly load insert valid JSON values.

Awesome! Wish this was in the documentation for the transformer, or... really anywhere!

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