Jquery – error TS2339: Property ‘modal’ does not exist on type ‘JQuery’

Based on Tomasz Nurkiewiczs answer, the "problem" is that typescript is typesafe. :) So the document.getElementById() returns the type HTMLElement which does not contain a value property. The subtype HTMLInputElement does however contain the value property.

So a solution is to cast the result of getElementById() to HTMLInputElement like this:

var inputValue = (<HTMLInputElement>document.getElementById(elementId)).value;

<> is the casting operator in typescript. See the question TypeScript: casting HTMLElement.

The resulting javascript from the line above looks like this:

inputValue = (document.getElementById(elementId)).value;

i.e. containing no type information.

Bootstrap has a few functions that can be called manually on modals:

$('#myModal').modal('toggle');
$('#myModal').modal('show');
$('#myModal').modal('hide');

You can see more here: Bootstrap modal component

Specifically the methods section.

So you would need to change:

$('#my-modal').modal({
    show: 'false'
}); 

to:

$('#myModal').modal('show'); 

If you're looking to make a custom popup of your own, here's a suggested video from another community member:

https://www.youtube.com/watch?v=zK4nXa84Km4