Access a DOM element in Aurelia

Question

How would you go about accessing a DOM element in Aurelia? This is a broad and general question, but I have a feeling there are one or two preferred ways to do this. I have two current cases in Aurelia now:

In the template I have a form. I want to access the form element in the view-model, on VM canDeactivate(), to interrupt a user navigating away from a half filled out form. So the scope in which I'm trying to access the element can be considered local.

In another view-model I want to hide navigation on VM activate(). Navigation resides in another view-model/template pair so the scope may be considered global.

Answer 1

As Rob suggested, use ref. For your example:

view

<form ref="myForm"></form>

viewModel

class ViewModel { 

    canDeactivate() {
        var form = this.myForm;
        // do stuffs
    }
}

For more information on the ref attribute, see here: http://aurelia.io/docs/binding/basics#function-references

Answer 2

Use binding system's ref capability. See the docs http://aurelia.io/docs/binding/basics#referencing-elements

Answer 3

Another option; if your view-model is exposed as a @customElement, its DOM element can be injected in the constructor:

@customElement
@inject(Element)
export class MyCustomElement {
    constrctor(element) {
        logger.info(element) // ==> <my-custom-element></my-custom-element>
    }
}

Answer 4

Just as another point I came across when trying to use this for myself, the ref variable isn't available during construction, and this isn't clear in the documentation. You can begin to reference the element as mentioned above (http://aurelia.io/hub.html#/doc/article/aurelia/binding/latest/binding-basics/5) anytime during or after the attached method is called.

Answer 5

Typescript version

@transient()
@autoinject
export class ViewModel { 
    myForm: any;
    canDeactivate() {
        var form = this.myForm;
        // do stuffs
    }
}