ln.ethercat/ln.ethercat.service/www/static/js/ecapp.js

class EthercatApplication
{

    constructor(options){
        this.state = { state: "N/A", slaves: [] };
        this.processdata = [];
        this.refresh_interval = 1000;
        this.ac_sockets = [];

        this.subscriptions = {};
        this.subscribed = {
            sdo: []
        }

        this.data = {
            slaves: {            
            }
        };

        let pageURI = window.location;
        let scheme = pageURI.scheme == "https" ? "wss:" : "ws:";
        let host   = pageURI.host;
        this.base_url = scheme + "//" + host;

        this.connectMainSocket();
    }

    connectMainSocket(){
        this.socket = this.connectWebSocket("/api/v1/socket", true);
        this.socket.onmessage = (evt)=>{
            let message = JSON.parse(evt.data);
            switch (message.event)
            {
                case "state":
                    this.applyState(message.value);
                    break;
                case "pdo":
                    this.processdata = message.value;
                    break;
                case "sdo":
                    this.subscribed.sdo = message.value;
                    break;
                default:
                    //console.log("unknown event received: " + message.event);
                    break;
            }
        };
        this.socket.onerror = (evt)=>{
            console.log("weboscket error: ", evt);
            this.socket.close();
        };
        this.socket.onclose = (evt)=>{
            console.log("weboscket closed: ", evt);
            if (evt.target == this.socket)
                setTimeout(()=>this.connectMainSocket(), 1000);
        };
    }

    connectWebSocket(path, keep){
        let ws = new WebSocket(this.base_url + path);
        if (!keep)
        {
            console.log("add to dispose list:", ws);
            this.ac_sockets.push(ws);
        }
        return ws;
    }

    closeWebSockets(){
        while (this.ac_sockets.length)
        {
            let ws = this.ac_sockets.pop();
            console.log("disposing:", ws);
            ws.close();
        }
    }

    sendMessage(eventName, o){
        this.socket.send(JSON.stringify({
            event: eventName,
            value: o
        }));
    }

    applyState(state){
        this.state = state;
    }

    POST(url, o){
        return fetch(url, {
            method: "POST",
            headers: {
                "Content-Type": "application/json"
            },
            body: JSON.stringify(o)
        })
    }

    getSDOList(slave_id){
        if (!this.data.slaves[slave_id])
            this.data.slaves[slave_id] = {};
        if (!this.data.slaves[slave_id].sdolist)
        {
            this.data.slaves[slave_id].sdolist = [];

            fetch("/api/v1/slaves/" + slave_id + "/sdo")
            .then((b) => {
                b.json()
                .then((json)=>{
                    json.forEach((sdo)=>{
                        this.data.slaves[slave_id].sdolist.push(sdo);
                    });
                });
            });    
        }
        return this.data.slaves[slave_id].sdolist;
    }

    subscribe(slave, sdo_index){
        slave = parseInt(slave);
        if (!this.subscriptions[slave]) this.subscriptions[slave] = {};
        if (!Object.keys(this.subscriptions[slave]).includes(sdo_index))
        {
            this.subscriptions[slave][sdo_index] = 1;
            this.sendMessage("subscribe", [
                {
                    Slave: slave,
                    Index: sdo_index,
                    SubIndex: 0,
                },
            ]);
        } else {
            this.subscriptions[slave][sdo_index]++;
        }
    }

    unsubscribe(slave, sdo_index){
        slave = parseInt(slave);
        if (this.subscriptions[slave] && Object.keys(this.subscriptions[slave]).includes(sdo_index))
        {
            this.subscriptions[slave][sdo_index]--;
            if (!this.subscriptions[slave][sdo_index])
            {
                this.sendMessage("unsubscribe", [
                    {
                        Slave: slave,
                        Index: sdo_index,
                        SubIndex: 0,
                    },
                ]);
            }
        }

    }

    requestState(slave_id, state){
        this.POST("/api/v1/slaves/" + slave_id + "/state", { state });
    }

}