I wanted to call a function defined in a first.js file in second.js file. Both files are defined in an HTML file like:
<script type="text/javascript" src="first.js"></script>
<script type="text/javascript" src="second.js"></script>
I want to call fn1() defined in first.js in second.js. From my searches answers were if first.js is defined first it is possible, but from my tests I haven't found any way to do that.
Here is my code:
second.js
document.getElementById("btn").onclick = function() {
fn1();
}
first.js
function fn1() {
alert("external fn clicked");
}
A function cannot be called unless it was defined in the same file or one loaded before the attempt to call it.
A function cannot be called unless it is in the same or greater scope then the one trying to call it.
You declare function fn1 in first.js, and then in second you can just have fn1();
1.js:
function fn1 () {
alert();
}
2.js:
fn1();
index.html :
<script type="text/javascript" src="1.js"></script>
<script type="text/javascript" src="2.js"></script>
You could consider using the es6 import export syntax. In file 1;
export function f1() {...}
And then in file 2;
import { f1 } from "./file1.js";
f1();
Please note that this only works if you're using <script src="./file2.js" type="module">
You will not need two script tags if you do it this way. You simply need the main script, and you can import all your other stuff there.
1st JS:
function fn(){
alert("Hello! Uncle Namaste...Chalo Kaaam ki Baat p Aate h...");
}
2nd JS:
$.getscript("url or name of 1st Js File",function(){
fn();
});
You can make the function a global variable in first.js
and have a look at closure and do not put it in document.ready put it outside
you can use ajax too
$.ajax({
url: "url to script",
dataType: "script",
success: success
});
same way you can use jquery getScript
$.getScript( "ajax/test.js" )
.done(function( script, textStatus ) {
console.log( textStatus );
})
.fail(function( jqxhr, settings, exception ) {
$( "div.log" ).text( "Triggered ajaxError handler." );
});
declare function in global scope with window
first.js
window.fn1 = function fn1() {
alert("external fn clicked");
}
second.js
document.getElementById("btn").onclick = function() {
fn1();
}
include like this
<script type="text/javascript" src="first.js"></script>
<script type="text/javascript" src="second.js"></script>
use "var" while creating a function, then you can access that from another file. make sure both files are well connected to your project and can access each other.
file_1.js
var firstLetterUppercase = function(str) {
str = str.toLowerCase().replace(/\b[a-z]/g, function(letter) {
return letter.toUpperCase();
});
return str;
}
accessing this function/variable from file_2.js file
firstLetterUppercase("gobinda");
output => Gobinda
It should work like this:
1.js
function fn1() {
document.getElementById("result").innerHTML += "fn1 gets called";
}
2.js
function clickedTheButton() {
fn1();
}
index.html
<html>
<head>
</head>
<body>
<button onclick="clickedTheButton()">Click me</button>
<script type="text/javascript" src="1.js"></script>
<script type="text/javascript" src="2.js"></script>
</body>
</html>
output
Try this CodePen snippet: link .
Please note this only works if the
<script>
tags are in the body and NOT in the head.
So
<head>
...
<script type="text/javascript" src="first.js"></script>
<script type="text/javascript" src="second.js"></script>
</head>
=> unknown function fn1()
Fails and
<body>
...
<script type="text/javascript" src="first.js"></script>
<script type="text/javascript" src="second.js"></script>
</body>
works.
This is actually coming very late, but I thought I should share,
in index.html
<script type="text/javascript" src="1.js"></script>
<script type="text/javascript" src="2.js"></script>
in 1.js
fn1 = function() {
alert("external fn clicked");
}
in 2.js
fn1()
Use cache if your server allows it to improve speed.
var extern =(url)=> { // load extern javascript
let scr = $.extend({}, {
dataType: 'script',
cache: true,
url: url
});
return $.ajax(scr);
}
function ext(file, func) {
extern(file).done(func); // calls a function from an extern javascript file
}
And then use it like this:
ext('somefile.js',()=>
myFunc(args)
);
Optionally, make a prototype of it to have it more flexible. So that you don't have to define the file every time, if you call a function or if you want to fetch code from multiple files.
first.js
function first() { alert("first"); }
Second.js
var imported = document.createElement("script");
imported.src = "other js/first.js"; //saved in "other js" folder
document.getElementsByTagName("head")[0].appendChild(imported);
function second() { alert("Second");}
index.html
<HTML>
<HEAD>
<SCRIPT SRC="second.js"></SCRIPT>
</HEAD>
<BODY>
method in second js<br/>
method in firstjs ("included" by the first)
</BODY>
</HTML>
window.onload = function(){
document.getElementById("btn").onclick = function(){
fn1();
}
// this should work, It calls when all js files loaded, No matter what position you have written
});
// module.js
export function hello() {
return "Hello";
}
// main.js
import {hello} from 'module'; // or './module'
let val = hello(); // val is "Hello";
reference from https://hype.codes/how-include-js-file-another-js-file
My idea is let two JavaScript call function through DOM.
The way to do it is simple ...
We just need to define hidden js_ipc html tag.
After the callee register click from the hidden js_ipc tag, then
The caller can dispatch the click event to trigger callee.
And the argument is save in the event that you want to pass.
When we need to use above way ?
Sometime, the two javascript code is very complicated to integrate and so many async code there. And different code use different framework but you still need to have a simple way to integrate them together.
So, in that case, it is not easy to do it.
In my project's implementation, I meet this case and it is very complicated to integrate. And finally I found out that we can let two javascript call each other through DOM.
I demonstrate this way in this git code. you can get it through this way. (Or read it from https://github.com/milochen0418/javascript-ipc-demo)
git clone https://github.com/milochen0418/javascript-ipc-demo
cd javascript-ipc-demo
git checkout 5f75d44530b4145ca2b06105c6aac28b764f066e
Anywhere, Here, I try to explain by the following simple case. I hope that this way can help you to integrate two different javascript code easier than before there is no any JavaScript library to support communication between two javascript file that made by different team.
<html>
<head>
<link rel="stylesheet" type="text/css" href="css/style.css" />
</head>
<body>
<div id="js_ipc" style="display:none;"></div>
<div id="test_btn" class="btn">
<a><p>click to test</p></a>
</div>
</body>
<script src="js/callee.js"></script>
<script src="js/caller.js"></script>
</html>
And the code
css/style.css
.btn {
background-color:grey;
cursor:pointer;
display:inline-block;
}
js/caller.js
function caller_add_of_ipc(num1, num2) {
var e = new Event("click");
e.arguments = arguments;
document.getElementById("js_ipc").dispatchEvent(e);
}
document.getElementById("test_btn").addEventListener('click', function(e) {
console.log("click to invoke caller of IPC");
caller_add_of_ipc(33, 22);
});
js/callee.js
document.getElementById("js_ipc").addEventListener('click', (e)=>{
callee_add_of_ipc(e.arguments);
});
function callee_add_of_ipc(arguments) {
let num1 = arguments[0];
let num2 = arguments[1];
console.log("This is callee of IPC -- inner-communication process");
console.log( "num1 + num2 = " + (num1 + num2));
}
better late than never
(function (window) {const helper = { fetchApi: function () { return "oke"}
if (typeof define === 'function' && define.amd) {
define(function () { return helper; });
}
else if (typeof module === 'object' && module.exports) {
module.exports = helper;
}
else {
window.helper = helper;
}
}(window))
index html
<script src="helper.js"></script>
<script src="test.js"></script>
in test.js file
helper.fetchApi()
I have had same problem. I have had defined functions inside jquery document ready function.
$(document).ready(function() {
function xyz()
{
//some code
}
});
And this function xyz() I have called in another file. This doesn't working :) You have to defined function above document ready.
TLDR: Load Global Function Files first, Then Load Event Handlers
Whenever you are accessing an element within a JS file or <script> block, it is essential to check to make sure that element exists, i.e., jQuery's $(document).ready() or plain JS's document.addEventListener('DOMContentLoaded', function(event)....
However, the accepted solution does NOT work in the event that you add an event listener for the DOMContentLoaded, which you can easily observe from the comments.
Procedure for Loading Global Function Files First
The solution is as follows:
Separate the logic of your JS script files so that each file only contains event listeners or global, independent functions.
Load the JS script files with the global, independent functions first.
Load the JS script files with event listeners second. Unlike the other previous files, make sure to wrap your code in document.addEventListener('DOMContentLoaded', function(event) {...}). or document.Ready().
Hopefully this is a no-brainer for all you experts, but I can't find the answer. I want to click on an element on Page A that will take me to Page B and automatically perform a function (here it's called showGrp) defined on Page B. On Page A, I want to click something like this (obviously, it doesn't work, but I think it conveys the idea):
<span onclick="location.assign('http://happy.com/pageB.htm').('showGrp(); return false;')">
<h2>Search Topics</h2>
</span>`
Short answer: there's no way to do that. You can't tell a new page to run a function through an old page
Long answer: You can, however, set up page B so it will know that if the request URL contains a certain argument in its GET data, it will run showGrp. i.e.:
going to http://happy.com/pageB.htm will do nothing
going to http://happy.com/pageB.htm?showGrp=1 will run function
You can use this function like so:
// put this wherever you want to run this - most probably when the page is loaded
if (getParameterByName('showGrp')) {
showGrp();
}
You could do something like this:
PageA:
<html>
<body>
<a href="pageB.html?f=showGrp">
<h2>Search Topics</h2>
</a>
</body>
</html>
PageB:
<html>
<head>
<script type="text/javascript">
function getQueryVariable(variable) {
var query = window.location.search.substring(1);
var vars = query.split('&');
for (var i = 0; i < vars.length; i++) {
var pair = vars[i].split('=');
if (decodeURIComponent(pair[0]) == variable) {
return decodeURIComponent(pair[1]);
}
}
}
var init = {
showGrp: function () {
console.log("Hello world!");
},
otherFunc: function() {
console.log("Lalala!");
}
};
init[getQueryVariable("f")]();
</script>
</head>
</html>
By making this you are able to execute whatever function you want just passing it name as an argument to the pageB's URL.
I would just put the code that you want to run in the window onload function on page B. I think that will do what you want.
window.onload = function() {
showGrp();
};
See a description of onload at the Mozilla Developers Network.
Page A should look like:
<div id = "yourclickobject" onclick="pageB.html"> Some random text </div>
Page B:
<head>
<script>
var myFunction = function(){
alert("hello world");
}
myFunction();
</script>
</head>
Does this help?
As soon as you go on page B myFunction is called. All you need to do is put it in the head
I have somehow a beginner's question about the following structure:
<body>
<p id="text_object">Some text</p>
<button id="button_change_text">change text on click</button>
// Individual script on page template
// ----------------------------------
<script type="text/javascript">
var object = $('#text_object');
changeTextOnLoad(object);
</script>
// Footer from included footer.php with universal main.js file
// ------------------------------------------------------------
<footer>
<script type="text/javascript" src="main.js">
</footer>
</body>
My main.js contains the following:
// declaration of function for writing new text into text object on load
function changeTextOnLoad(object) {
object.text('New text');
}
// declaration of click function
$('#button_change_text').on('click', function() {
$('#text_object').text('New text');
});
My problem: My console tells me that changeTextOnLoad() is undefined. But clicking on the button and changing the text by this way works perfectly fine. Where is the reason? Why in my main.js file does the click function get fired but not the changeTextOnLoad function?
You are calling your changeTextOnLoad function before the main.js file has loaded. Either put the function call in an onload event callback or put the include above the call
window.onload = function(){
var object = $('#text_object');
changeTextOnLoad(object);
};
//Or using addEventListener
window.addEventListener("load",function(){
var object = $('#text_object');
changeTextOnLoad(object);
});
//Or since you are using jQuery
$(document).ready(function(){
var object = $('#text_object');
changeTextOnLoad(object);
});
//Or
$(function(){
var object = $('#text_object');
changeTextOnLoad(object);
});
OR
<script type="text/javascript" src="main.js"></script>
<script type="text/javascript">
var object = $('#text_object');
changeTextOnLoad(object);
</script>
because main.js is another file, browser takes time to download it. But you run changeTextOnLoad(object); before that.
I've created links to transition yet when the function is supposed to be called using the onmousedown event I get an uncaught undefined function. Clearly my function is defined. I'm am still learning code so what is it I don't see or understand. Any tips will be greatly appreciated.
<html>
<head>
<script type="text/javascript"src="js/jquery.js"></script>
<script type="text/javascript" src="js/jquery-ui.js"></script>
<script type="javascript">
$(document).ready(function (){
var url = "phpajaxtut.php";
});
function swapContent(cv){
$("#myDiv").html("animated gif goes here").show();
.post(url, {contentVar:cv}, function(data){
$("#myDiv").html(data).show();
});
}
</script>
Click the text
Click the text
Click the text
</head>
<body >
<div id ="myDiv">My default content</div>
</body>
</html>
Why not just use $.click(); instead, since you're already using jQuery, and forgo the hyperlinks? You can easily style some spans to look like as if that's what you want. My example just updates some text, but in there you can place / call your function.
See here:
// html
<span>Click Me</span>
<br />
<span>Click Me</span>
// js
var n = 0;
$("span").click(function(){
$(this).text($(this).text() + " " + n++);
});
Do you need a $ before .post?
$.post(url, {contentVar:cv}, function(data){
$(document).ready(function (){
var url = "phpajaxtut.php";
});
The var url isn't global. It can only be used inside the function
var url; //global url
$(document).ready(function (){
url = "phpajaxtut.php"; // set global url
});
I need to handle 'tweet' event. That is what I have now, but it doesn't work:
<script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>
<script type="text/javascript">
function jsTweet() {
// some other stuf here
// ...
var urlTW = "https://twitter.com/intent/tweet?text=Text&url=http://my_url.com";
var winTW = window.open(urlTW,'','toolbar=0, status=0, width=650, height=360');
}
(function() {
twttr.events.bind('tweet', function(event) {
alert('tweet!!!!');
});
}());
</script>
<a href="javascript:void(0)" onClick="jsTweet();">
Several things :
1/ Close your anchor tag.
2/ Your anonymous function is called only when the page is loaded. The twttr object doesn't exist at this time. So there is no binding done. Debug your function with Firebug or something, this should appear as an error.