CODEWITHSUNDEEP
angulartypescriptparentheses
ping pong
ping pong

Reputation: 285

Call a function within a function without parentheses

I have a service in angular which in some cases dynamically creates a html input like this:

this.fileInput = this.document.createElement('input');
this.fileInput.setAttribute('type', 'file');
this.fileInput.setAttribute('accept', 'image/*');
this.fileInput.addEventListener('change', this.onFileSelected);
this.fileInput.click();

The method onFileSelected:

async onFileSelected(event) {
const file = event.target.files[0];
const reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = (_event) => {
  this.uploadFile(reader.result);
};
}

When I call it i get the following error:

this.uploadFile is not a function

I'm guessing this is because I call the function without parentheses, but I cant call it any other way. Is there any workaround for this?

Upvotes: 0

Views: 72

Answers (1)

David
David

Reputation: 34445

Modify the way you add the handler

this.fileInput.addEventListener('change', e=> this.onFileSelected(e));

Normally, this should now correctly reference your class (I believe that it will reference the file input dom element otherwise)

Upvotes: 1

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