Skip to main content

Three Most Common jQuery Events Part Three: On()


On()

On() works similarly to addEventListener. It lets you specify the type of event to listen for.

If we want to style the h1 text content when h1 is clicked, we could write:

$("h1").on("click", function(){
$("h1").css("color", "green");})

Inside on(), we give the type of event we want to listen for, in this case is "click". Then, we pass a function to change the h1 style when the event happens.


If we want to bold the button text when the mouse is on that button, we will select "button", then set "mouseenter" as event type, and pass a function which will make the text bold.


If we want the bold button back to normal, we only need to change the "mouseenter" to "mouseleave", and change "bold" to "normal".




What's the difference between on() and click()?

In most case, click() and on("click") will both get the job done, but there is one key difference: click() only adds listeners for existing elements, but on() will add listeners for all potential future elements.




Comments

Popular posts from this blog

Intermediate Express.js: How To Add Styles & Partials in EJS File?

So far, we only have simple HTML tags and ejs tags in each ejs file. Every template page has no style at all. And the basic HTML header and footer are also missing. Today, I learned how to add styles and partials in ejs file. Link Style Step One: Touch a Separate CSS file I create a new directory "Style" under the "EJSDemo" directory, then I add a new CSS file "app.css" inside "Style" folder. Step Two: Add app.use(express.static()) in the app.js I add app.use(express.static("style")) in the "app.js". This will tell Express.js to serve the content of "Style" directory. Step Three: Write styles in CSS file I simple give body an orange background color and set text color to be grey. Step Four: Link to CSS file in the EJS file I just add <link> tag to link the "app.css" file on the top of the h1 tag in each ejs template. As the result, when I run the app and...

Seven Most Common jQuery Methods Last Part: ADD/REMOVE/TOGGLE CLASS()

Add, remove and toggleClass is also a very common way to manipulate style. .addClass() and .removeClass() I add two class selector in the style tag. Class one is to change text color to be green, and class two is change both text and background color.  Now I refresh the page and change h1 text to green by using addClass() method: $("h1").addClass("one") .  If you want to remove the style, you can change it to removeClass("one"). I do the same thing to the list. I change the list color and add a background color by adding the class two style value: $("li").addClass("two") . .toggleClass()  According to jQuery, toggerClass method can add or remove one or more classes from each element in the set of matched elements, depending on either the class's presence or the value of the state argument. I only want to change the first list item color and background by writing: $("li").first().toggleClas...

Intro to Backend: Is Browser The Only Place To Send HTTP Request?

Today,  I begin to learn the second part of web develop course: backend. Frontend is the stuff that we can see and interactive with, such as HTML, CSS, and JS. We can type our code, style our page, or write some function to make interaction. However, backend is everything else. For example, we type Target web address in the Internet Browser. As we hit "enter", there are a few steps to go through: 1. The HTTP request is sent to a particular server's IP address. 2. The server figures out what to send us 3. It sends a HTTP response back to us Those process we are hard to see, and it happens in less than one second. The instructor said that the browser is not the only place to send the HTTP request, and there are so many choices out there. In this learning course, we are going to use Postman App . Postman allows us to make HTTP requests and viewer responses. It is really for developers to understand how things are working or debug something. In the P...