I was wondering what would be the best way to execute a java-script code only on specific pages.
Let's imagine we have a template-based web-site, rewrite rule for the content ist set, jquery available and it basically looks like this:
<!DOCTYPE html>
<html>
<head>
<script src="script.js"></script>
</head>
<body>
...
include $content;
..
</body>
</html>
content 'info' contains a button, we want something to happen on click, content 'alert' should give us a message when you hover a text field.
What is the best way to trigger these actions, without running into an error, because the object is not found?
Option one: using window.location.pathname
$(document).ready(function() {
if (window.location.pathname == '/info.php') {
$("#button1").click(function(){
//do something
})
}else if(window.location.pathname == '/alert.php'){
$("#mytextfield").hover(){
alert('message');
}
}
Option two: checking if elements exist
$(document).ready(function() {
if ($("#button1").length > 0) {
$("#button1").click(function(){
//do something
})
}else if ($("#mytextfield").length > 0){
$("#mytextfield").hover(){
alert('message');
}
}
Option three: include the script in the loaded template
//stands for itself
Is there a better solution? Or do I have to get along with one of these solutions?
Your experience, usage, or any links related to this topic are appreciated.
//EDIT:
I might have choosen a bad example, the actual code would be somethin like:
mCanvas = $("#jsonCanvas");
mMyPicture = new myPicture (mCanvas);
where the myPicture constructor get's the context of the canvas element, and throws an error, if mCanvas is undefined.
But yes, it is an option.
To execute JavaScript in a browser you have two options — either put it inside a script element anywhere inside an HTML document, or put it inside an external JavaScript file (with a . js extension) and then reference that file inside the HTML document using an empty script element with a src attribute.
The best practice is to put JavaScript <script> tags just before the closing </body> tag rather than in the <head> section of your HTML. The reason for this is that HTML loads from top to bottom. The head loads first, then the body, and then everything inside the body.
Another way to execute the JavaScript after the page is loaded is by using the onload method. The onload method waits until the page gets loaded. As soon as it does, this process then executes the JavaScript code. There are two ways of writing a JavaScript code.
In this post, I want to show you how to include JavaScript, just on specific pages or areas in WordPress. First thing you have to do, is to add the JavaScript you want to load in your theme folder of WordPress. To keep everything organized, create a folder called “Scripts” or “Js”.
In practice, it won’t be a big deal if you need to do this only for one script, but it’s very useful when your site uses large number of JavaScripts which don’t need to be loaded every time on every page. It’s pretty simple and still can speed up your page loading significantly.
To keep everything organized, create a folder called “Scripts” or “Js”. That means that if you have permalinks active and a page called home, the JavaScript will load just on that page. This is a simple HTML comment to keep organized or to make the life easier to other developers who might have to work with your code.
Set a class
attribute to your body tag.
<body class="PageType">
And then in your script..
$(function(){
if($('body').is('.PageType')){
//add dynamic script tag using createElement()
OR
//call specific functions
}
});
I would use the switch statement and a variable. (I'm using jQuery!)
var windowLoc = $(location).attr('pathname'); //jquery format to get window.location.pathname
switch(windowLoc){
case "/info.php":
//code here
break;
case "/alert.php":
//code here
break;
}
//use windowLoc as necessary elsewhere
This will allow you to change what "button" does based on the page that you're on. If I understood your question correctly; this is what I would do. Also, if I had were serving large amounts of javascript, I would simply add a new JS file completely.
var windowLoc = $(location).attr('pathname'); //jquery format to get window.location.pathname
switch(windowLoc){
case "/info.php":
var infoJS = document.createElement('script');
infoJS.type = 'text/javascript';
infoJS.src = 'location/to/my/info_file.js';
$('body').append(infoJs);
break;
case "/alert.php":
var alertJS = document.createElement('script');
alertJS.type = 'text/javascript';
alertJS.src = 'location/to/my/alert_file.js';
$('body').append(alertJs);
break;
}
Hope this helps -
Cheers.
A little different approach than checking the URL path : You can group page specific event handlers in a single function and then in each include, have a domready which will call these functions.
Eg: in script.js
you have two functions (outside domready) viz. onPage1Load()
and onPage2Load()
.
While in your page1.php
you have a $(document).ready(onPage1Load)
and so on for other pages. This will make sure that unintended event handlers are not registered.
You can also use vanilla javascript to do the same
console.log(window.location.href);
const host = "http://127.0.0.1:5500/";
// JAVASCRIPT FOR INDEX PAGE
if (window.location.href == host + 'index.html') {
console.log("this is index page");
}
// JAVASCRIPT FOR ORDER PAGE
if (window.location.href == host + 'order.html') {
console.log("this is order page");
}
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