“this” cannot be used in typescript function (Angular)

Question

I want to reference the keyword \"this\" in a typescript class in my Angular project. But it cannot be used. I always get the error that the variable I want to change is not

Answer 1

Since you're using Typescript, you can use arrow functions to preserve the context you expect (this will refer to what you want).

In SubmitForm(), replace this.loggedIn with ()=>this.loggedIn(). The same change should be made to this.failed if that's a function.

DBEventProxy.instance().dbevent.login(
    this.contactForm['username'], 
    this.contactForm['password'], 
    ()=>this.loggedIn(), 
    ()=>this.failed()
);

See the Typescript wiki

Red flags for this

The biggest red flag you can keep in mind is the use of a class method without immediately invoking it. Any time you see a class method being referenced without being invoked as part of that same expression, this might be incorrect.