Call a javascript function from HTML element - javascript

I have a button on a webpage which loads after a given amount of time, works well but my client would like an easy way to add a button that calls this function so he can add dynamic values to it.
In this instance the button should remove a class after 5 seconds of the page/element loading:
Problem, the function is not being called, I have checked the reference to the javascript file is correct, I suspect the issue is the way I am calling the function, here is my code:
<a href="somewhere.com" id="myButton" window.onload='showButton("myButton", "5000")';
class="invisible">Now you can see me!</a>
function showButton(id, time) {
setTimeout(function() { showButtonPrep(id, time); }, time);
console.log("I have fired!");
}
function showButtonPrep(id, time) {
var button = document.getElementById(id);
button.classList.remove('invisible');
}
The console does not log the string so I can see it is not being loaded
I have tried variations of the load, i.e
window.load
this.load
The javascript file containing the function is in the footer, if I put an alert in top of the javascript file that does fire.

window.onload is not a valid HTML attribute for <a>. This seems a mixup between HTML and JavaScript.
You should put that inside a script:
window.onload = () => showButton("myButton", 5000);
function showButton(id, time) {
setTimeout(function() {
showButtonPrep(id, time);
}, time);
console.log("I have fired! Now wait 5 seconds...");
}
function showButtonPrep(id, time) {
var button = document.getElementById(id);
button.classList.remove('invisible');
}
.invisible { display: none }
Now you can see me!

Related

How to refresh a script after some time using Javascript

There is a variable I want to update every minute.
So am curious whether there is a way in Javascript where I can refresh the whole script after some time instead of the variable itself.
<script>
function vName(){
videos = $('#videos').text();
}
vName();
Use setInterval. Here hello will print each and every 3sec
setInterval(function(){ console.log("Hello"); }, 3000);
You could achive this using an event to listen to the element's change:
(function () {
"use strict";
let videos = '';
$("#videos").on("change", evt => {
videos = $(evt.target).val();
console.log(videos);
});
})();
body {
margin: 20px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input id="videos" type="text">
Solution
Set interval is a function which is being used to perform any functionality after a specific desired time span . The function is always called again and again after that time period . The below code is an example for setInterval.
Code:-
setInterval(function(){ alert("Video is here "); }, 9000);
Explanation
you can call any method in place of "alert("Video is here")" and the desired time period is being given in place of "9000" that means the specific function is being called after every 9 seconds
You can put your code in setInterval() function, like this
setInterval(()=>{
//your script here
function vName(){
videos = $('#videos').text();
}
vName();
}, 60000);

Call user defined jQuery function with JS

I use a jQuery window libray https://github.com/humaan/Modaal
which triggers events this way $("class of element").modaal({arg1, arg2,...});
--- I updated my question here to make it more general and used an iframe / Html instead of an external svg ---
To trigger an element e.g. in an external Html which is loaded within an iframe, I applied the following code to the iframe:
<iframe src="External.html" id="mainContent" onload="access()"></iframe>
which calls this function:
function access() {
var html = document.getElementById("mainContent").contentDocument.getElementById("IDofDIVelement");
html.addEventListener('click', function() {clicker();});
}
function clicker()
{
// console.log('hooray!');
$("#mainContent").contents().find("IDofDIVelement").modaal({});
//return false;
}
Actually it will only work on every second click. Any idea what I did not consider properly?
Best
You do not need to wait windows loading but iframe only:
$(function() {
$("#mainContent").bind("load",function(){
var myIframeElement = $(this).contents().find(".modaal");
myIframeElement.modaal({
content_source: '#iframe-content',
type: 'inline',
});
});
});
The reason why it did not work was that the iframe was not completely loaded, while jQuery tried to attach the function. As $(document).ready(function(){} did not work, the workaround was to initialize it with
$( window ).on( "load",function() {
$("#mainContent").contents().find("IDofDIVelement").modaal({});
});
This worked properly to attach the functionallity to an element within the iframe.
Actually modaal will vanish the envent handler after the overlay was opened and closed again.
So maybe someone wants to trigger an iframe element for modaal, too, here is a setup which would solve this issue.
(It can be optimised by #SvenLiivaks answer):
$(window).on("load", function() {
reload();
});
function reload() {
var length = $("#iframeID").contents().find("#IDofDIVelement").length;
// The following check will return 1, as the iframe exists.
if (length == 0) {
setTimeout(function() { reload() }, 500);
} else {
$("#iframeID").contents().find("#IDofDIVelement").modaal({
content_source: '#modalwrapper',
overlay_close: true,
after_close: function reattach() {
reload();
}
});
}
}

<div> value not updating in html page

I am using jquery to auto update a part of the HTML page. Following is the code
$(document).ready( function() {
$('#auto').load("static/l.txt");
refresh();
});
function refresh() {
setTimeout(function() {
$('#auto').load("static/l.txt");
refresh();
}, 1000);
}
The id of the HTML div tag to be updated is auto
The file static/l.txt is continuously being updated by another python program.
But when I load the html page , the div only gets updated once and does not update the value until and unless I open the developers console on the browser.
I am hosting the web page using Flask in python
How about trying this?
var counter =0 ;
$(document).ready( function() {
$('#auto').val("starting");
refresh();
});
function refresh() {
setInterval( function() {
counter ++;
$('#auto').val(counter);
}, 1000);
}
Use a callback to know, when the content is actually loaded and move the function definition in the ready block, also.
$(document).ready(function() {
function loadData() {
$('#auto').load('static/l.txt', function(completed) {
setTimeout(loadData, 1000);
});
}
loadData();
});

Prevent duplcate ajaxLoad event calls added with a click event

I am using MVC Razor - The overall goal is to create a "print view" pop-up page.
The print view button is on the parent page, when clicked, an ajax event is fired which will populate an empty div with the contents that are to be included in the print preview:
//from the view
#Ajax.ActionLink("prntPreview", "Display", new { ID = Model.Detail.ID }, new AjaxOptions { UpdateTargetId = "modal" }, new { #class = "btnPreview" })
then, using JavasScript/jQuery I clone the contents of that newly populated div and create a new window with the contents:
//in the scripts file
$('.btnPreview').on('click', function () {
$(document).ajaxStop(function () {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
}, 300);
});
});
function PopupPrint(data) {
var mywindow = window.open('', '', 'height=500,width=800,resizable,scrollbars');
mywindow.document.write(data);
mywindow.focus();
//do some other stuff here
}
This is where I run into difficulty. The first time I click, everything is working as expected - however, if you do not navigate away from the parent page and try to use the print preview button a second time, the popup will be created twice, then three times etc. with each additional click.
I think that the problem is because each time the .btnPreview is clicked, a new $(document).ajaxStop event is being created, causing the event to fire multiple times.
I have tried to create the ajaxStop as a named function which is declared outside the scope of the click event and then clear it but this produces the same result:
var evnt = "";
$('.btnPreview').on('click', function () {
evnt =
$(document).ajaxStop(function () {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
evnt = "";
}, 300);
});
});
I also have other ajaxStop events initialised so don't want to completely unbind the ajaxStop event. Is it possible to get the name or something from each ajax event so that I can clear just that event or similar?
You can prevent adding additional triggers by checking with a variable outside of scope like this:
(function() {
var alreadyAdded = false;
$('.btnPreview').on('click', function() {
if (!alreadyAdded) {
$('.eventTrigger').click(function() {
console.log('printing!');
});
alreadyAdded = true;
}
});
})();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button class="btnPreview">Add Event</button>
<button class="eventTrigger">Trigger</button>
Please note that the variable and function are encapsulated in a self-executing anonymous function and do not pollute global space.
The output of the sample can be seen in the developer console. If you remove the if-check then every click on the "Add Event" button produces an additional print statement on the "Trigger" button each time it is clicked (which is your problem). With the if, there will ever only be one event on the trigger button.
There were 2 issues which I needed to address.
The answer is to unbind the ajax event after it has checked that the request had completed and to unbind and reattach the button click trigger.
This is how I did it:
//in the scripts file
$('.btnPreview').off('click').on('click', function () {
$(document).ajaxComplete(function (e) {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
}, 300);
$(this).off(e);
});
});
I unbound the click event by adding .off('click') before the .on. this is what stopped it popping up multiple times.
The other issue was that anytime any ajax event completed (triggered by something else) that would also create the popup - to get around that, I added $(this).unbind(e); to the end of the code block which removed the ajaxComplete binding which was being triggered each time any ajax event completed.

How to put a delay in loading of images in the same area to make it look like an animation?

Basically I have like 2 images, and I want to show one for 3 seconds, then replace it with another, in the same img tag.
This is what I have so far:
$(function(){
$("#image_area").hide();
$('#W40').click(function(){
$("#image_area img").remove();
show_image_area('40');
});
});
So the flow is first hide the #image_area, then when #W40 button is clicked, remove any current image in the area and run the show_image_area function, the function is as follows:
function show_image_area(world){
if (!$("#image_area img").length) { //only run if no current image exists
$('#image_area').show();
$('#image_area').prepend("<img id='tw_image' src='world+"/7.png' width=\"1000\" height=\"1030\" />");
setTimeout($("#tw_image").attr("src", "world+"/8.png"), 3000);
}
}
Right now, if I run these code, the 8.png shows almost immediately, and there are no 3 second delay that I wanted.
You have an extra " in the code: should be $("#tw_image").attr("src", world+"/8.png").
Also, I would put $("#tw_image").attr("src", world+"/8.png") in a function of it's own.
function SwapImage(world)
{
$("#tw_image").attr("src", world+"/8.png");
}
Then change your last line to setTimeout(SwapImage(world), 3000);
This isnt fully tested but gives you an idea:
$(function(){
$("#image_area").hide();
$('#W40').click(function(){
$("#image_area img").remove()
show_image_area('40');
});
});
function show_image_area(world){
var newImg = $('<img />').css({width: 1000, height: 1030}).attr({id: 'tw_image', src: world+'/7.png');
if ( !$("#image_area img").length ) { //only run if no current image exists
$('#image_area').prepend(newImg).show('fast');
setTimeout( function() {
$("#tw_image").attr("src", world+"/8.png");
}, 3000);
}
}
Basically yours was immediately firing the setTimeout function instead of passing in a function to be fired later
That's because the first parameter of setTimeout is not a function.
Also there is an extra quote on that line.
Also, the "world" variable might need closure (can't remember).
Try
function show_image_area(world){
if (!$("#image_area img").length) { //only run if no current image exists
$('#image_area').show();
$('#image_area').prepend("<img id='tw_image' src='world+"/7.png' width=\"1000\" height=\"1030\" />");
var myWorld = world;
setTimeout(function () {$("#tw_image").attr("src", myWorld+"/8.png");}, 3000);
}
}
Your setTimeout call is a bit off:
setTimeout($("#tw_image").attr("src", "world+"/8.png"), 3000);
The first argument should be the function to execute:
setTimeout(function() { $("#tw_image").attr("src", "world/8.png") }, 3000);
Also, I'm not sure what "world" is so I merged it into the new src path to fix a stray double quote.

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