How to call a method inside another method in a class in Javascript?

Question

How do you properly call a method inside another method in a JavaScript class?

export class XMLLoader{

constructor(){



}

// Processes the XML request, i.e retrieves the relevant data etc.
 processXMLReq(xhttp){

    let resultXML = xhttp.responseXML;
    let resultText = xhttp.responseText;


    console.log("The result is: " + resultXML);
    console.log("The result is: " + resultText);

    let x = resultXML.getElementsByTagName("road")[0].childNodes[0].nodeValue;


    console.log("The first 'road' node value is: " + x);

}

loadXMLDoc(url){

    let xhttp = new XMLHttpRequest();

    xhttp.onreadystatechange = function(){
        if(this.readyState === 4 && this.status === 200){
            this.processXMLReq(xhttp);
        }

    };

    xhttp.open("GET", url, true);       // the argument "true" means that the request will be executed in async
    xhttp.send();

}

};

As you can see I'm trying to call processXMLReq() inside loadXMLDoc(), why is this not working. Only way I have made it to work is by putting processXMLReq inside the constructor and making it static. This class is supposed to be a utility class for a searchbar class. How can I make it so that I can call processXMLReq inside loadXMLDoc. Because inside my searchbar class I just want to do something like this:

componentDidMount(){

  //  let xmlLoader = new XMLLoader();

    let xmlLoader = new XMLLoader();

    xmlLoader.loadXMLDoc('someURL', this.processXMLReq);


}

Paul · Accepted Answer · 2017-09-30 16:06:17Z

2

Static methods aren't accessed with 'this' they are accessed from the constructor or the classname:

XMLLoader.processXMLReq(data);

or

XMLLoader.constructor.processXMLReq(data);

answered Sep 30, 2017 at 16:06

Paul

36.4k12 gold badges98 silver badges124 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Skarsh Over a year ago

Ah, yes of course! But imagine processXMLReq wasn't static. How would you do it then? Because that is what I actually intended to ask, just forgot to remove the static in front. Sorry for the confusion.

Paul Over a year ago

If it's not static, then addressing it with this.processXMLReq() should work.

Paul Over a year ago

Actually, looking at your consuming code, are you asking how the consumer references it?

Skarsh Over a year ago

Yes, because without it being static, and then I get an error that processXMLReq is undefined, although it is an member method.

Paul Over a year ago

In loadXml(), you can reference this.processXML(), but outside of the class instance you cannot. You'd have to do xmlLoader.processXML().

Cobolt · Accepted Answer · 2017-09-30 16:08:25Z

0

XMLLoader. processXMLreq(xhttp) because it is a static method

answered Sep 30, 2017 at 16:08

Cobolt

9532 gold badges11 silver badges25 bronze badges

Collectives™ on Stack Overflow

How to call a method inside another method in a class in Javascript?

2 Answers 2

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related