-The websocket protocol x-afb-ws-json1
-=====================================
+# The websocket protocol x-afb-ws-json1
The WebSocket protocol *x-afb-ws-json1* is used to communicate between
an application and a binder. It allows access to all registered apis
This document gives a short description of the protocol *x-afb-ws-json1*.
A more formal description has to be done.
-
-Architecture
-------------
+## Architecture
The protocol is intended to be symmetric. It allows:
- - to CALL a remote procedure that returns a result
- - to push and receive EVENT
-
+- to CALL a remote procedure that returns a result
+- to push and receive EVENT
-Messages
---------
+## Messages
Valid messages are made of *text* frames that are all valid JSON.
Valid messages are:
Calls:
-```
+
+```txt
[ 2, ID, PROCN, ARGS ]
[ 2, ID, PROCN, ARGS, TOKEN ]
```
Replies (3: OK, 4: ERROR):
-```
+
+```txt
[ 3, ID, RESP ]
-[ 3, ID, RESP, TOKEN ]
[ 4, ID, RESP ]
-[ 4, ID, RESP, TOKEN ]
```
Events:
-```
+
+```txt
[ 5, EVTN, OBJ ]
```
| PROCN | string | The procedure name to call of the form "api/verb"
| ARGS | any | Any argument to pass to the call (see afb_req_json that returns it)
| RESP | any | The response to the call
-| TOKEN | string | The token in case of refresh
+| TOKEN | string | The authorisation token
| EVTN | string | Name of the event in the form "api/event"
| OBJ | any | The companion object of the event
Below, an example of exchange:
-```
+```txt
C->S: [2,"156","hello/ping",null]
S->C: [3,"156",{"response":"Some String","jtype":"afb-reply","request":{"status":"success","info":"Ping Binder Daemon tag=pingSample count=1 query=\"null\"","uuid":"ec30120c-6997-4529-9d63-c0de0cce56c0"}}]
```
+## History
+
+### 14 November 2019
+
+Removal of token returning. The replies
+
+```txt
+[ 3, ID, RESP, TOKEN ]
+[ 4, ID, RESP, TOKEN ]
+```
+
+are removed from the specification.
-Future
-------
+## Future
Here are the planned extensions:
- - add binary messages with cbor data
- - add calls with unstructured replies
+- add binary messages with cbor data
+- add calls with unstructured replies
This could be implemented by extending the current protocol or by
allowing the binder to accept either protocol including the new ones.
-
-Javascript implementation
--------------------------
+## Javascript implementation
The file **AFB.js** is a javascript implementation of the protocol.
AFB = function(base, initialtoken){
if (typeof base != "object")
- base = { base: base, token: initialtoken };
+ base = { base: base, token: initialtoken };
var initial = {
- base: base.base || "api",
- token: base.token || initialtoken || "HELLO",
- host: base.host || window.location.host,
- url: base.url || undefined
+ base: base.base || "api",
+ token: base.token || initialtoken || "HELLO",
+ host: base.host || window.location.host,
+ url: base.url || undefined
};
var urlws = initial.url || "ws://"+initial.host+"/"+initial.base;
/*********************************************/
var AFB_context;
{
- var UUID = undefined;
- var TOKEN = initial.token;
-
- var context = function(token, uuid) {
- this.token = token;
- this.uuid = uuid;
- }
-
- context.prototype = {
- get token() {return TOKEN;},
- set token(tok) {if(tok) TOKEN=tok;},
- get uuid() {return UUID;},
- set uuid(id) {if(id) UUID=id;}
- };
-
- AFB_context = new context();
+ var UUID = undefined;
+ var TOKEN = initial.token;
+
+ var context = function(token, uuid) {
+ this.token = token;
+ this.uuid = uuid;
+ }
+
+ context.prototype = {
+ get token() {return TOKEN;},
+ set token(tok) {if(tok) TOKEN=tok;},
+ get uuid() {return UUID;},
+ set uuid(id) {if(id) UUID=id;}
+ };
+
+ AFB_context = new context();
}
/*********************************************/
/**** ****/
/*********************************************/
var AFB_websocket;
{
- var CALL = 2;
- var RETOK = 3;
- var RETERR = 4;
- var EVENT = 5;
-
- var PROTO1 = "x-afb-ws-json1";
-
- AFB_websocket = function(on_open, on_abort) {
- var u = urlws;
- if (AFB_context.token) {
- u = u + '?x-afb-token=' + AFB_context.token;
- if (AFB_context.uuid)
- u = u + '&x-afb-uuid=' + AFB_context.uuid;
- }
- this.ws = new WebSocket(u, [ PROTO1 ]);
- this.url = u;
- this.pendings = {};
- this.awaitens = {};
- this.counter = 0;
- this.ws.onopen = onopen.bind(this);
- this.ws.onerror = onerror.bind(this);
- this.ws.onclose = onclose.bind(this);
- this.ws.onmessage = onmessage.bind(this);
- this.onopen = on_open;
- this.onabort = on_abort;
- }
-
- function onerror(event) {
- var f = this.onabort;
- if (f) {
- delete this.onopen;
- delete this.onabort;
- f && f(this);
- }
- this.onerror && this.onerror(this);
- }
-
- function onopen(event) {
- var f = this.onopen;
- delete this.onopen;
- delete this.onabort;
- f && f(this);
- }
-
- function onclose(event) {
- for (var id in this.pendings) {
- try { this.pendings[id][1](); } catch (x) {/*TODO?*/}
- }
- this.pendings = {};
- this.onclose && this.onclose();
- }
-
- function fire(awaitens, name, data) {
- var a = awaitens[name];
- if (a)
- a.forEach(function(handler){handler(data);});
- var i = name.indexOf("/");
- if (i >= 0) {
- a = awaitens[name.substring(0,i)];
- if (a)
- a.forEach(function(handler){handler(data);});
- }
- a = awaitens["*"];
- if (a)
- a.forEach(function(handler){handler(data);});
- }
-
- function reply(pendings, id, ans, offset) {
- if (id in pendings) {
- var p = pendings[id];
- delete pendings[id];
- try { p[offset](ans); } catch (x) {/*TODO?*/}
- }
- }
-
- function onmessage(event) {
- var obj = JSON.parse(event.data);
- var code = obj[0];
- var id = obj[1];
- var ans = obj[2];
- AFB_context.token = obj[3];
- switch (code) {
- case RETOK:
- reply(this.pendings, id, ans, 0);
- break;
- case RETERR:
- reply(this.pendings, id, ans, 1);
- break;
- case EVENT:
- default:
- fire(this.awaitens, id, ans);
- break;
- }
- }
-
- function close() {
- this.ws.close();
- this.ws.onopen =
- this.ws.onerror =
- this.ws.onclose =
- this.ws.onmessage =
- this.onopen =
- this.onabort = function(){};
- }
-
- function call(method, request, callid) {
- return new Promise((function(resolve, reject){
- var id, arr;
- if (callid) {
- id = String(callid);
- if (id in this.pendings)
- throw new Error("pending callid("+id+") exists");
- } else {
- do {
- id = String(this.counter = 4095 & (this.counter + 1));
- } while (id in this.pendings);
- }
- this.pendings[id] = [ resolve, reject ];
- arr = [CALL, id, method, request ];
- if (AFB_context.token) arr.push(AFB_context.token);
- this.ws.send(JSON.stringify(arr));
- }).bind(this));
- }
-
- function onevent(name, handler) {
- var id = name;
- var list = this.awaitens[id] || (this.awaitens[id] = []);
- list.push(handler);
- }
-
- AFB_websocket.prototype = {
- close: close,
- call: call,
- onevent: onevent
- };
+ var CALL = 2;
+ var RETOK = 3;
+ var RETERR = 4;
+ var EVENT = 5;
+
+ var PROTO1 = "x-afb-ws-json1";
+
+ AFB_websocket = function(on_open, on_abort) {
+ var u = urlws;
+ if (AFB_context.token) {
+ u = u + '?x-afb-token=' + AFB_context.token;
+ if (AFB_context.uuid)
+ u = u + '&x-afb-uuid=' + AFB_context.uuid;
+ }
+ this.ws = new WebSocket(u, [ PROTO1 ]);
+ this.url = u;
+ this.pendings = {};
+ this.awaitens = {};
+ this.counter = 0;
+ this.ws.onopen = onopen.bind(this);
+ this.ws.onerror = onerror.bind(this);
+ this.ws.onclose = onclose.bind(this);
+ this.ws.onmessage = onmessage.bind(this);
+ this.onopen = on_open;
+ this.onabort = on_abort;
+ }
+
+ function onerror(event) {
+ var f = this.onabort;
+ if (f) {
+ delete this.onopen;
+ delete this.onabort;
+ f && f(this);
+ }
+ this.onerror && this.onerror(this);
+ }
+
+ function onopen(event) {
+ var f = this.onopen;
+ delete this.onopen;
+ delete this.onabort;
+ f && f(this);
+ }
+
+ function onclose(event) {
+ for (var id in this.pendings) {
+ try { this.pendings[id][1](); } catch (x) {/*TODO?*/}
+ }
+ this.pendings = {};
+ this.onclose && this.onclose();
+ }
+
+ function fire(awaitens, name, data) {
+ var a = awaitens[name];
+ if (a)
+ a.forEach(function(handler){handler(data);});
+ var i = name.indexOf("/");
+ if (i >= 0) {
+ a = awaitens[name.substring(0,i)];
+ if (a)
+ a.forEach(function(handler){handler(data);});
+ }
+ a = awaitens["*"];
+ if (a)
+ a.forEach(function(handler){handler(data);});
+ }
+
+ function reply(pendings, id, ans, offset) {
+ if (id in pendings) {
+ var p = pendings[id];
+ delete pendings[id];
+ try { p[offset](ans); } catch (x) {/*TODO?*/}
+ }
+ }
+
+ function onmessage(event) {
+ var obj = JSON.parse(event.data);
+ var code = obj[0];
+ var id = obj[1];
+ var ans = obj[2];
+ AFB_context.token = obj[3];
+ switch (code) {
+ case RETOK:
+ reply(this.pendings, id, ans, 0);
+ break;
+ case RETERR:
+ reply(this.pendings, id, ans, 1);
+ break;
+ case EVENT:
+ default:
+ fire(this.awaitens, id, ans);
+ break;
+ }
+ }
+
+ function close() {
+ this.ws.close();
+ this.ws.onopen =
+ this.ws.onerror =
+ this.ws.onclose =
+ this.ws.onmessage =
+ this.onopen =
+ this.onabort = function(){};
+ }
+
+ function call(method, request, callid) {
+ return new Promise((function(resolve, reject){
+ var id, arr;
+ if (callid) {
+ id = String(callid);
+ if (id in this.pendings)
+ throw new Error("pending callid("+id+") exists");
+ } else {
+ do {
+ id = String(this.counter = 4095 & (this.counter + 1));
+ } while (id in this.pendings);
+ }
+ this.pendings[id] = [ resolve, reject ];
+ arr = [CALL, id, method, request ];
+ if (AFB_context.token) arr.push(AFB_context.token);
+ this.ws.send(JSON.stringify(arr));
+ }).bind(this));
+ }
+
+ function onevent(name, handler) {
+ var id = name;
+ var list = this.awaitens[id] || (this.awaitens[id] = []);
+ list.push(handler);
+ }
+
+ AFB_websocket.prototype = {
+ close: close,
+ call: call,
+ onevent: onevent
+ };
}
/*********************************************/
/**** ****/
/**** ****/
/*********************************************/
return {
- context: AFB_context,
- ws: AFB_websocket
+ context: AFB_context,
+ ws: AFB_websocket
};
};
-```
\ No newline at end of file
+```
Code Review / src / app-framework-binder.git / commitdiff