Trying to write my own Module...

nbrenn

@mochman
Thanks for the link to the markdown page! My OP is edited accordingly. I do understand that I’m missing necessary code in order to make it function. I’m just not really sure what.

I would like to print the <name> and <watts> if possible. The XML returned has a lot more data, but for the sake of this post, I cut it down to just include the first three items. I would like to print all three.

mochman

Your code seems to abruptly end in the middle of the getDom() function, but from what I see, it looks like you are sending the URL to a node_helper.js that I assume will get the data you want.

My recommendation would be to look at this page and see how to parse the XML to take out what you want. You then can use this data to create a simple table to display each <name> and <watts> in the getDom() function. I don’t think you’ll need a node_helper.js to do this though. You can probably just do it in the main .js file. Unless you’re running into a Access-Control-Allow-Origin error. Then you can get around it by using node_helper.js

Another way people have done this has been described here.

nbrenn

@mochman
Thanks for the response and the examples. Are some of the XML methods in the tutorial you linked to, often used in Mirror modules?

I wasn’t planning on using a node_helper.js and my code does abruptly end in the middle of the getDOM(). I got stuck when trying to find out how to extract specifics from the XML, like <name> and <watts>.

Do you know of any other good module examples that would have similar XML structure, where specific objects were extracted from?

strawberry 3.141

@nbrenn

Assuming xml is the xml file you get as response from the server

var channels = xml.getElementsByTagName("channel");

for(var i = 0; i < channels.length; i++){
  for(var n = 0; n < channels[i].children.length; n++){
    if(channels[i].children[n].tagName === "name" || channels[i].children[n].tagName === "watts"){
      console.log(channels[i].children[n].textContent);
    }
  }
}

will ouput

"Main Power Main Panel"
"-9"
"West Solar 1"
"-165"
"West Solar 2"
"-143"
"Both Bathroom Outlets"
"0"
"1st Floor Lights"
"0"

ooom416354

I am kind of in the same boat. I actually have an old JS file which would return data in JSON format using the MTA API for the MM1. This allowed me to see if my train was delayed or not before leaving the house. I am trying to figure out an easy way to port to over to the new mirror but I am not at all a JavaScript programmer. If anyone would like to have a look at the current code for the MM1 and maybe try to port it over it might help some folks who live in the NYC area. Or if anyone knows if there is a current module which takes JSON results and displays them on the screen I can try to mock that up to integrate this. Thanks!

nbrenn

@strawberry-3.141 Thanks for the snippet! I have a better idea of how to extract the data from the XML with your example.

If I want to simply output what you have provided in your post, would I need to simply put your snippet into my getDom() function and add the .name to my .css file (similar to how I have the .watts)?

So I know that’s probably incorrect, but I just tried it and an error returned:
Cannot read property getElementsByClassName of null. I think that I am having trouble understanding how to create the div object for which to add in the data.

cowboysdude

@nbrenn post what you’ve rewritten so they can better understand where your error may be and what I do [whcn I added humidity to the stock weather app] was to look at other modules and pick it apart to see how they were using div and such for styling to better get an understanding how it fit together. These guys are awesome, they like to help!

Actually posting what you have now would help me too! :) I’m trying to create something myself.

strawberry 3.141

@nbrenn I’m assuming that you saved your server response into this.xml

getDom: function(){
  var wrapper = document.createElement("div");

  if(this.xml){
    var channels = this.xml.getElementsByTagName("channel");
    for(var i = 0; i < channels.length; i++){
      for(var n = 0; n < channels[i].children.length; n++){
        if(channels[i].children[n].tagName === "name" || channels[i].children[n].tagName === "watts"){
          var element = document.createElement("div");
          element.classList.add(channels[i].children[n].tagName);
          element.innerHTML = channels[i].children[n].textContent;
          wrapper.appendChild(element);
        }
      }
    }
  } else {
    wrapper.innerHTML = "NO DATA";
  }
  return wrapper;
}

this would create two div container for every channel one for the name and the other for watts. each of them would have the css class .name or .watts

nbrenn

Thanks for the great support.

I currently have no errors with what you’ve helped provide me with. However, it displays the else condition, and NO DATA.

Right now, my MMM-EMonitor.js looks like the following:

Module.register ("MMM-EMonitor", {
    
    //default module config.
    defaults: {
        // Insert defaults here
        interval: 900000 // Every 15 mins
    },
    
    getStyles: function() {
        return ["MMM-EMonitor.css"];
    },
    
    // Define the start sequence
    start: function() {
        Log.log("Starting module: " + this.name);
        
        //this.securitykey = REDACTED;
        this.url = 'https://api.emonitor.us/location/getCurrentData?security_key=REDACTED';
        this.getCurrentData(this);
    },
    
   getCurrentData: function(that) {
       that.sendSocketNotification('GET-CURRENT-DATA', that.url);
       setTimeout(that.getCurrentData, that.config.interval, that);
    },
    

   getDom: function(){
 	 var wrapper = document.createElement("div");

  	if(this.xml){
   	 var channels = this.xml.getElementsByTagName("channel");
   	 for(var i = 0; i < channels.length; i++){
    	   for(var n = 0; n < channels[i].children.length; n++){
       		if(channels[i].children[n].tagName === "name" || channels[i].children[n].tagName === "watts"){
          	var element = document.createElement("div");
          	element.classList.add(channels[i].children[n].tagName);
          	element.innerHTML = channels[i].children[n].textContent;
          	wrapper.appendChild(element);
        	}
      	}
    	}
  	} else {
    		wrapper.innerHTML = "NO DATA";
  	}
  	return wrapper;
}
});

and my css looks like the following:

.MMM-EMonitor .centered {
    text-align: center;
}

Like I mentioned, the NO DATA is showing up. The security key is working, and returns the XML which I have in my original post.

mochman

You don’t have this.xml defined anywhere in your script. If you look at @strawberry-3-141’s post, it says:

I’m assuming that you saved your server response into this.xml

You need to create a function that uses the URL and saves that data in a variable called xml. Since your program never does that, this.xml isn’t defined so your if/else always goes to “NO DATA”.

Why do you have

getCurrentData: function(that) {
       that.sendSocketNotification('GET-CURRENT-DATA', that.url);
       setTimeout(that.getCurrentData, that.config.interval, that);
    },

in your program? Did you just see it in another persons code? This code snippet sends your URL to node_helper.js. Are you using that node_helper to pull the XML data from the website? If so, you’re going to need a socketNotificationReceived function to get the data and put it into the xml variable.

The modules documentation shows you some examples of that.