A New Chapter for MagicMirror: The Community Takes the Lead
Read the statement by Michael Teeuw here.
Read the statement by Michael Teeuw here.
TypeError: Cannot read property 'getElementsByClassName' of null
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Hi,
I’m at my wit’s end!
Based on module “MMM-FHEM by BenRoe” I’ve created a module to receive event changes from the home automation pimatic. The module works fine. Then I started to write a second modul and can’t get rid of the error:
Cannot read property ‘getElementsByClassName’ of nulltTo isolate the problem I reduced the code to the example from the module development page.
Module.register("HelloWorld",{ // Default module config. defaults: { text: "Hello World!" }, start: function() { var self = this; setInterval(function() { self.updateDom(); // no speed defined, so it updates instantly. }, 1000); //perform every 1000 milliseconds. }, // Override dom generator. getDom: function() { var wrapper = document.createElement("div"); wrapper.className = 'MyHelloWorld'; wrapper.innerHTML = this.config.text; return wrapper; } });
Following the console log:
What’ s wrong? I need help from an expert!
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@Mr.Sponti that happens because you are trying to update the DOM before its even created
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Try addicting this method to your module:
notificationReceived: function(notification, payload) { if (notification === 'DOM_OBJECTS_CREATED') { // you can now schedule the dom update method. } }
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