B4J Question [ b4j_ws.js ] how do I get information if the server is disconnected?

[Waldemar Lima]

Hello guys, I'm using b4j_ws.js with JServer, does anyone know how to tell me how I know the server was disconnected or connected to js?

 

[aeric]

Check this:

[server] Automatic Reconnecting WebSocket

When working with WebSocket handlers the client maintains an online connection. The connection is expected to be kept alive for as long as needed. However there are cases where the connection can be temporary broken. Especially when the client is a mobile browser. Using the...

www.b4x.com

 

[Waldemar Lima]

but how do i know if you disconnected, an error occurred and connected inside b4j_ws.js?

 

[aeric]

but how do i know if you disconnected, an error occurred and connected inside b4j_ws.js?

If you checked the video posted by Erel, you should noticed that a message popped out saying that "the server is not available".

 

[Waldemar Lima]

If you checked the video posted by Erel, you should noticed that a message popped out saying that "the server is not available".

I read some topics about JavaScript on google, and I got this result :


b4j_ws.js :

//B4J WebSockets client library v0.92 edited



/*jslint browser: true*/

/*global $, jQuery, WebSocket*/

/*jshint curly: false */

"use strict";

var b4j_ws;

var b4j_closeMessage = false;

//only called as a result of a server request that is waiting for result.

//this method should not be called in any other case.

function b4j_sendData(data) {

    b4j_ws.send(JSON.stringify({type: "data", data: data}));

}

function b4j_raiseEvent(eventName, parameters) {

    try {

        if (b4j_ws.readyState !== 1) {

            if (b4j_closeMessage === false) {

                window.console.error("connection is closed.");

                if (typeof ReconnectingWebSocket !== 'undefined')

                    window.alert("Server is currently not available.");

                else

                    window.alert("Connection is closed. Please refresh the page to reconnect.");

                b4j_closeMessage = true;

            }

        } else {

            b4j_closeMessage = false;

            b4j_ws.send(JSON.stringify({type: "event", event: eventName, params: parameters}));

        }

    } catch (e) {

        window.console.error(e);

    }

}

function b4j_addEvent(selector, event, eventName, preventDefault) {

    var obj = $(selector);

    if (obj.length > 0) {

        obj.on(event, function (e) {

            if (preventDefault) {

                e.preventDefault();

                e.stopPropagation();

            }

            b4j_raiseEvent(eventName, {which: e.which, target: e.target.id, pageX: e.pageX, pageY: e.pageY, metaKey: e.metaKey});

        });

    }

}

function b4j_addAutomaticEvents(data) {

    $.each(data, function (index, value) {

        b4j_addEvent("#" + value.id, value.event, value.id + "_" + value.event, true);

    });

}

function b4j_runFunction(func, params) {

    return window[func].apply(null, params);

}



function b4j_eval(params, script) {

    var f = new Function(script);

    return f.apply(null, params);

}



function b4j_connect(absolutePath,callopenfunction,callclosefunction,callerrorfunction) {

    if (typeof WebSocket === 'undefined') {

        window.alert("WebSockets are not supported by your browser.");

        return;

    }

    var l = window.location, fullpath;

    fullpath = ((l.protocol === "https:") ? "wss://" : "ws://") + l.hostname + ":" + l.port + absolutePath;

    if (typeof ReconnectingWebSocket === 'undefined') {

        b4j_ws = new WebSocket(fullpath);

    } else {

        b4j_ws = new ReconnectingWebSocket(fullpath);

    b4j_ws.onmessage = function (event) {

        var ed = JSON.parse(event.data);

        if (ed.etype === "runmethod") {

            $(ed.id)[ed.method].apply($(ed.id), ed.params);

        } else if (ed.etype === "runmethodWithResult") {

            b4j_sendData($(ed.id)[ed.method].apply($(ed.id), ed.params));

        } else if (ed.etype === "setAutomaticEvents") {

            b4j_addAutomaticEvents(ed.data);

        } else if (ed.etype === "runFunction") {

            b4j_runFunction(ed.prop, ed.value);

        } else if (ed.etype === "runFunctionWithResult") {

            b4j_sendData(b4j_runFunction(ed.prop, ed.value));

        } else if (ed.etype === "eval") {

            b4j_eval(ed.value, ed.prop);

        } else if (ed.etype === "evalWithResult") {

            b4j_sendData(b4j_eval(ed.value, ed.prop));

        } else if (ed.etype === "alert") {

            window.alert(ed.prop);

        }

      

    };

    //  I needed to know information about events and call a function from another file.js to display connection error information to my users ...

    b4j_ws.onopen  = function (event) {

  

        callopenfunction(event.data);



    };



    b4j_ws.onclose   = function (event) {

  

        callclosefunction(event.data);



    };

  

    b4j_ws.onerror    = function (event) {

  

        callerrorfunction(event.data);



    };



    } 

}

I did it in a hurry ... For those who want to improve the code above, it will be a pleasure!