Scripting websockets easy

The bitshares developer community use different ways to interact with the core api with the websocket.

Some of this methods are curl, pybitshares, wscat and many others.

The most used tool is wscat, this is a great tool but it is no scriptable. I found myself pasting the same commands like login and subscribe to database, crypto and other apis over and over again.

I was after scripting wscat since a while until @thewalrus asked in telegram for the same thing.

Ptython is the choice as it is probably the most used language in the bitshares community.

https://pypi.python.org/pypi/websocket-client

Simply install by:

pip install websocket-client

Confirm the install by using the wsdump.py tool. This should do the same as wscat:

Press Ctrl+C to quit
> {"method": "call", "params": [1, "login", ["", ""]], "id": 2}

< {"id":2,"result":true}
> {"method": "call", "params": [1, "database", []], "id": 3}

< {"id":3,"result":2}

> {"method": "call", "params": [2, "get_objects", [["1.11.8799012"]]], "id": 4}
< {"id":4,"result":[{"id":"1.11.8799012","op":[14,{"fee":{"amount":281946,"asset_id":"1.3.0"},"issuer":"1.2.89940","asset_to_issue":{"amount":100,"asset_id":"1.3`
`.1276"},"issue_to_account":"1.2.142352","memo":{"from":"BTS8LWkZLmsnWjgtT1PNHT5XGAu1z1ueQkBHBQTVfECFVQfD3s7CF","to":"BTS6F1ZetzyG5FvjRiPjSkAjJfCqfr8AGbnGfH9FAGWZ`
M3SGVumj5","nonce":"380763353028914","message":"912991d1bb5bccccbd41dbad533836e667e5c5e9a31290c857ed6c5ea01756dd4d5893f1644c16c019170a4d0de346a2"},"extensions":[
]}],"result":[0,{}],"block_num":14086551,"trx_in_block":0,"op_in_trx":0,"virtual_op":48819}]}
>```

Create a python script that will execute the commands one after the other and get the output:

`from websocket import create_connection`
`ws = create_connection("ws://localhost:8090")`
`ws.send('{"method": "call", "params": [1, "login", ["", ""]], "id": 2}')`
`result =  ws.recv()`
`print result`


`ws.send('{"method": "call", "params": [1, "database", []], "id": 3}')`
`result =  ws.recv()`
`print result`

`ws.send('{"method": "call", "params": [2, "get_objects", [["1.11.8799012"]]], "id": 4}')`
`result =  ws.recv()`
`print result`

`ws.close()`

Execute as:

`root@NC-PH-1346-07:~# python testws.py `
`{"id":2,"result":true}`
`{"id":3,"result":2}`
`{"id":4,"result":[{"id":"1.11.8799012","op":[14,{"fee":{"amount":281946,"asset_id":"1.3.0"},"issuer":"1.2.89940","asset_to_issue":{"amount":100,"asset_id":"1.3.1`
`276"},"issue_to_account":"1.2.142352","memo":{"from":"BTS8LWkZLmsnWjgtT1PNHT5XGAu1z1ueQkBHBQTVfECFVQfD3s7CF","to":"BTS6F1ZetzyG5FvjRiPjSkAjJfCqfr8AGbnGfH9FAGWZM3`
`SGVumj5","nonce":"380763353028914","message":"912991d1bb5bccccbd41dbad533836e667e5c5e9a31290c857ed6c5ea01756dd4d5893f1644c16c019170a4d0de346a2"},"extensions":[]}`
`],"result":[0,{}],"block_num":14086551,"trx_in_block":0,"op_in_trx":0,"virtual_op":48819}]}`
`root@NC-PH-1346-07:~#`


You get the results of the 3 calls inside the python script. 

Check the "Long-lived connection" sample of the websocket-client documentation in order to make a script that can receive updates.