Struggling with implementing Angular and TypeScript in this particular method

I'm dealing with a code snippet that looks like this:

myMethod(data: any, layerId: string, dataSubstrings): void {
    someObject.on('click', function(e) {
        this.api.getSomething(a).subscribe((result: any) => { // ERROR CALL 1. It is from another component
            // code
            this.outSideMethod(a)); // ERROR CALL 2

            }
        }, (error: any) => {
            return {};
        })
    });


outSideMethod(a): any[] {
    //etc
}

I am encountering an issue while trying to call this.api.getSomething(a)); (as well as outSideMethod()) and receiving the error message 'Cannot read property 'getSomething' of undefined.'

I seem to be struggling with using 'this' in the context of object-oriented programming (OOP), can someone kindly provide me with some insights?

Answer №1

The context object you are referencing (the one indicated by the keyword 'this') does not have the api property set, which means that the getSomething method cannot be executed.

Make sure to review how the 'this' keyword behaves by visiting https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this, as its behavior depends on how the method is invoked.

In Angular, if you are injecting this dependency, make sure to add the scope modifier (such as private) to the parameter of the constructor in order to bind it to an internal property and access it using 'this'.

Answer №2

Consider updating the function to a lambda expression.

Instead of using:

someObject.on('click', function(e) {} )

Try this approach:

someObject.on('click', (e) =>{});

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