Cinnamon javascript desklet won't refresh when calling webpage

Question

I'm completely new to Cinnamon and javascript (but am fairly competent on python).

I've been trying to update an existing desklet to show some football scores from a json feed on my network.

The problem I have is that the script won't refresh the data. I've narrowed this down to being caused by my web request. I have tried to prove this by having the desklet just show the time (in seconds) so I can see whether it is updating or not. When I comment out the two web request lines, the time updates as expected. When they're left in, the time doesn't change. The trouble is, I don't know why this stops the update.

desklet.js:

const Lang = imports.lang;
const Mainloop = imports.mainloop;
const St = imports.gi.St;
const Json = imports.gi.Json;
const Soup = imports.gi.Soup;


const Desklet = imports.ui.desklet;
const Settings = imports.ui.settings;

const _httpSession = new Soup.SessionAsync();

function MyDesklet(metadata, desklet_id){
    this._init(metadata, desklet_id);
}

MyDesklet.prototype = {
    __proto__: Desklet.Desklet.prototype,

    _init: function(metadata, desklet_id){
        Desklet.Desklet.prototype._init.call(this, metadata);
        this._date = new St.Label({style_class: "football-desklet-label"});
        this.setContent(this._date);
        this.setHeader(_("Football scores"));

        this.settings = new Settings.DeskletSettings(this, this.metadata["uuid"], desklet_id);

        this.settings.bindProperty(Settings.BindingDirection.IN,
                                   "date-format",
                                   "format",
                                   function() {},
                                   null);

    this.settings.bindProperty(Settings.BindingDirection.IN,
                   "font-size",
                   "size",
                   this._onSettingsChanged,
                   null);

        this._onSettingsChanged();

      this.getJSON("http://www.bbc.co.uk");
    },

    getJSON: function(url) {

    // If I leave these two lines in, the time doesn't update.

        let message = Soup.Message.new('GET', url);
        _httpSession.send_message (message);


        let displayDate = new Date();
        this._date.set_text(displayDate.toLocaleFormat("%s"));
        this.timeout = Mainloop.timeout_add_seconds(1, Lang.bind(this,this.getJSON));  
    },


    _onSettingsChanged: function(){
        this._date.style="font-size: " + this.size + "pt; font-style: italic";
    },

    on_desklet_removed: function() {
    Mainloop.source_remove(this.timeout);
    },

    _updateDate: function(){
        let displayDate = new Date();
        this._date.set_text("Hello:" + displayDate.toLocaleFormat("%s"));
        this.timeout = Mainloop.timeout_add_seconds(1, Lang.bind(this, this._updateDate));
    }
}

function main(metadata, desklet_id){
    let desklet = new MyDesklet(metadata, desklet_id);
    return desklet;
}

If you want to test this yourself, the other two files are

settings-schema.json:

{
    "font-size": {
        "type": "spinbutton",
        "default": 50,
        "min": 8,
        "max": 50,
    "units": "",
        "description" : "Font size:",
        "step": 1
    }
}

and metadata.json:

{
 "uuid": "dev@elparaguayo",
 "name": "Testing desklet",
 "description": "Could do anything...",
 "icon": "stock_calendar",
 "prevent-decorations": false
}

Any help to debug this would be greatly appreciated. Thank you.

Answer 1

I don't know the reason (so, if anyone can explain, please do so in the comments section here) but the answer was that the timeout function had to be in a different function.

The code therefore looks like this:

const Lang = imports.lang;
const Mainloop = imports.mainloop;
const St = imports.gi.St;
const Json = imports.gi.Json;
const Soup = imports.gi.Soup;


const Desklet = imports.ui.desklet;
const Settings = imports.ui.settings;

const _httpSession = new Soup.SessionAsync();

function MyDesklet(metadata, desklet_id){
    this._init(metadata, desklet_id);
}

MyDesklet.prototype = {
    __proto__: Desklet.Desklet.prototype,

    _init: function(metadata, desklet_id){
        Desklet.Desklet.prototype._init.call(this, metadata);
        this._date = new St.Label({style_class: "football-desklet-label"});
        this.setContent(this._date);
        this.setHeader(_("Football scores"));

        this.settings = new Settings.DeskletSettings(this, this.metadata["uuid"], desklet_id);

    this.settings.bindProperty(Settings.BindingDirection.IN,
                   "font-size",
                   "size",
                   this._onSettingsChanged,
                   null);

        this._onSettingsChanged();
        this._updateScore();
    },

    getJSON: function(url) {

   let message = Soup.Message.new('GET', url);
    _httpSession.send_message (message);
    if (message.status_code!== Soup.KnownStatusCode.OK) {
        this._date.set_text("Unable to contact server.");
        var sleep = 30
    } else {

    let jp = new Json.Parser();
    jp.load_from_data(message.response_body.data.toString(), -1);
    match=jp.get_root().get_object();
    let found=match.get_boolean_member('matchfound');
    if (found != true) {
        this._date.set_text("Chelsea are not playing today.");
        var sleep = 30
    } else {
        var sleep = match.get_int_member('sleep');
        match = match.get_object_member('match');
        let hometeam = match.get_string_member('hometeam');
        let awayteam = match.get_string_member('awayteam');
        let homescore = match.get_int_member('homescore').toString();
        let awayscore = match.get_int_member('awayscore').toString();
        this._date.set_text(hometeam + ' ' + homescore + '-' + awayscore + ' ' + awayteam);
    } 
    }
    return sleep;


    },


    _onSettingsChanged: function(){
        this._date.style="font-size: " + this.size + "pt;";
    },

    on_desklet_removed: function() {
    Mainloop.source_remove(this.timeout);
    },

    _updateScore: function(){
        let sleep = this.getJSON("PATH-TO-PRIVATE-JSON-FEED");
        let sleep = ~~(sleep/4)
        this.timeout = Mainloop.timeout_add_seconds(sleep, Lang.bind(this, this._updateScore));
    }
}

function main(metadata, desklet_id){
    let desklet = new MyDesklet(metadata, desklet_id);
    return desklet;
}