Stocks

[alexyak]

@ZTA0796 The original code does a hardcoded substring on the result:

var result = JSON.parse(body.substring(3, body.length));

You probably don’t need to do that.

[ZTA0796]

This post is deleted!

[ZTA0796]

@alexyak Thanks! I have one more question about syntax that I’m having trouble with.

I can pull the Yahoo JSON into the node_helper file and print it to the terminal without a problem. But when I try to reference it in the “getDom” function, I get nothing. I haven’t changed the code at the start of that function at all. But when it runs “this.result.length”, the length returned is 0.

I’m not super-familiar with the “this” syntax, but was hoping you or someone else might have an idea of why the JSON you pass would work, but not the JSON that I pass?

Thanks!

[chrisfoerg]

great! would also be good for rss feeds :-)

[alexyak]

@ZTA0796 Could you show your code?

[ZTA0796]

@alexyak Sure…see below.

In the node_helper.js:

getStocks: function (url) {
var self = this;

  request({ url: url, method: 'GET' }, function (error, response, body) {
      if (!error && response.statusCode == 200) {
        
          var result = JSON.parse(body);
          console.log(result.query.results.row);  //prints the JSON as expected to the terminal
          self.sendSocketNotification('STOCKS_RESULT', result);
      }
  });

},

//Subclass socketNotificationReceived received.
socketNotificationReceived: function(notification, payload) {
if (notification === ‘GET_STOCKS’) {
this.getStocks(payload);
}
}

});

in stocks.js:

getDom: function() {

    var wrapper = document.createElement("table");
    wrapper.className = 'normal regular small';
    
    var count = 0;

    var _this = this;

	console.log("in the DOM function");
	console.log("result is " + this);  //prints [object Object]
	console.log("result is " + _this); //prints [object Object]
	console.log("result length is " + this.result.length); //prints 0

    if (this.result.length > 0){
        this.result.forEach(function(stock) {
			//since length=0, it never gets in this loop
                           //
			//
},

scheduleUpdate: function(delay) {
	console.log("scheduled update check");
	var nextLoad = this.config.updateInterval;
	if (typeof delay !== "undefined" && delay >= 0) {
		nextLoad = delay;
	}

	var self = this;
	setInterval(function() {
		self.getStocks();
	}, nextLoad);
},

roundValue: function(value) {
   return Math.round(value*100)/100; 
},

getStocks: function () {
    var url = 'https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20csv%20where%20url%3D%27http%3A%2F%2Fdownload.finance.yahoo.com%2Fd%2Fquotes.csv%3Fs%3D' + this.config.stocks + '%26f%3Dsl1d1t1c1ohgv%26e%3D.csv%27%20and%20columns%3D%27symbol%2Cprice%2Cdate%2Ctime%2Cchange%2Ccol1%2Chigh%2Clow%2Ccol2%27&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys';
    this.sendSocketNotification('GET_STOCKS', url);
},


socketNotificationReceived: function(notification, payload) {
    if (notification === "STOCKS_RESULT") {
		console.log("notification received");
		console.log(payload);  //prints Object { query: Object }
        this.result = payload;
        this.updateDom(self.config.fadeSpeed);
    }    
},

[ZTA0796]

Upon looking at it further-- in the “socketNotificationReceived: function(notification, payload)” function in the module.js file, it seems that when I run console.log(this.result), it outputs my JSON:

Object { symbol: “MSFT”, price: “62.30”, date: “12/16/2016”, time: “4:00pm”, change: “-0.28”, col1: “62.95”, high: “62.95”, low: “62.12”, col2: “42453083” }

When I go to the “getDom” function and run “console.log(this.result)”, I get:

[object Object]

I’m just not sure why that change occurs, but that seems to be my issue. Any help is massively appreciated!

[alexyak]

@ZTA0796 The object that you get int the stocks.js is the deserialized javascript object. In your case it’s going to be a single row object. You could just access the properties list this:

this.result.symbol, this.result.price, etc…

-Alex

[ZTA0796]

@alexyak So that’s what I expected as well. Unfortunately, it is somehow getting messed up between the “socketNotificationReceived” function and the “getDom” function.

socketNotificationReceived: function(notification, payload) {
    if (notification === "STOCKS_RESULT") {
        this.result = payload;
        console.log(this.result);  //prints my JSON correctly console
        this.updateDom(self.config.fadeSpeed);
    }       

So the above works correctly. Below, however, it doesn’t seem to maintain and I can’t figure out why.

getDom: function() {

    var wrapper = document.createElement("table");
    wrapper.className = 'normal regular small';
    
    var count = 0;

    var _this = this;

	console.log("result is " + this.result); //prints "result is [object Object]"
	console.log("result length is " + this.result.length); //prints "result length is 0"
	console.log(this.symbol);  //prints "undefined"
    }

I apologize if I’m being thick, but I can’t figure out why it’s not working…

[ZTA0796]

Ok, so I think i figured it out. Still not sure why it worked, but for some reason, running a console.log("descriptive text " + this) seems to corrupt or change the type of “this”. If I put two consecutive console.log() calls–first with descriptive text, second with just “this”–then it works. Basically in the example above, if I just comment out the first two console.log() calls, then it no longer prints “undefined” and instead prints “MSFT”. Sorry for all the trouble!