dom-event | Add/remove DOM events

I'm new to React. I have an </code>. Before it is destroyed or removed I want to call some clean-up code. But I'm not sure how to call that method before destroy. Here is my code:</p> <p><strong>App.js</strong></p> <pre><code>import React, { Component } from "react"; import "./App.css"; export default class App extends Component { lang = "de-DE"; myMethod =()=> { var in_dom = document.body.contains("the_iframe"); var observer = new MutationObserver(function(mutations) { if (document.body.contains("the_iframe")) { if (!in_dom) { console.log("element inserted"); } in_dom = true; } else if (in_dom) { in_dom = false; console.log("element removed"); } }); observer.observe(document.body, {childList: true, subtree: true}); } render() { ... return ( <div className="App"> <header className="App-header"> <span className="App-link"> Change Language </span> <span className="App-link"> Logout </span> </header> <div> <iframe id="the_iframe" width="95%" height="200px" scrolling="no" beforeunload="myMethod()" > ); } }

I took help from here: DOM event when element is removed

Some information I took from here also: DOMContentLoaded, load, beforeunload, unload

Same thing as Javascript Window.GetSelection. Basically I want to be able to grab the selected text in an html input with Blazor.

I set up a thank you page redirection which is working fine. But I want to open the redirected URL in a new window. How can I do that?

Here is the code -

I have an angular directive that attaches to an event on the element:

I am adding Contact Form 7 to a page that also has a dynamically-generated HTML table with data specific to that user. When that user fills out the form and submits it, I have the form set up to send an HTML-formatted email back to us. I need to add the table as an HTML element in the email, but none of the methods I've tried are working. Assume a very basic table:

I am trying to make unit test for a @mouseover and @mouseleave event who's displaying a v-card-actions depending from the mouseover. I am using vue-test-utils in my vuejs2 webpack application. Here is what i found on the web : vue-utlis mouse click exemple . Thanks in advance to anyone who's helping

Here is my code actual html template code:

Is there a way to trigger an event when an HTML select list is dropped down? I'm not asking about when it closed, but when you first drop it down.

I'd like to set the selectedIndex = -1 when the user clicks on the down arrow of the drop-down.

Most websites begin their drop-down with a blank entry, or a dummy entry like "Select...". I'd like to just have the values themselves, and have the list clear itself whenever they click in.

This is what I started with, but it fires after they make a choice, which isn't what I want - I want only when the list drops down.

intro:

I want to test that if I click on the submit button, the onSubmit function is called. I assume this is possible from what I understand when I read the documentation:

1. https://sinonjs.org/releases/v6.1.5/spies/
2. https://vue-test-utils.vuejs.org/guides/#testing-key-mouse-and-other-dom-events

expected output:

• get the test to run and show me either pass or fail

actual output:

• none, I'm currently stuck at the following:

context:

in my test:

import NavBar from '@/components/layout/NavBar.vue'

in that component I have a (simplified version here) form:

Search

I want to test that if I click on the submit button, the onSubmit function is called.

My setup is Vue, BootstrapVue and Sinon. I understand I have to setup a spy that listens to a function being called.

This is the actual script in my component if that is helpful:

I have prepared a simple snippet below, one text input field, one button and one select. Clicking on the button programmatically focuses the input. Changing the select also focuses the input. This is the case in all desktop browsers and in android, but not in iOS. In iOS focusing works for the button but not for the select.