I have an html element, (lets say for simplicity) a label, and it has a title, so that a tooltip appears when you hover over the label.
I would like the tooltip to show a snapshot of some associated 'current' data. In actuality, the current price of the object that the label points to, but an analogue of this could be any data that potentially changes with time.
In native JavaScript, how can I detect the activation of the tooltip, so that I can re-calc the data before the tooltip is shown?
I know that I could use setInterval() or something to keep the title string current, but it would be more efficient to only re-calculate the title string when the tooltip is shown.
Try using data-* attribute of element to store values, setting element.title to data-* of element , onmouseover , onmouseleave events
var elem = document.querySelector("div");
var interval = setInterval(function() {
elem.dataset.tooltip = 1+ +elem.dataset.tooltip;
}, 1000);
elem.onmouseover = elem.onmouseleave = function(e) {
console.log(e)
this.title = this.dataset.tooltip;
}
<div data-tooltip="0" title="0">hover</div>
Something like this may work, but you'll be at the mercy of the latency of the request for updating the data (assuming that the source of the updated price data is a http request or socket connection) and that probably won't be quicker than the browser will display the tooltip. It's certainly not going to be consistent or reliable.
<p id="text" title="initialtitle">Text</p>
<script>
var n = 0;
document.getElementById("text");
text.onmouseover = function() {
n++;
text.title = n;
};
</script>
Depending on the specifics of what you're doing and how much room for maneuver you have, another solution could be to open a WebSocket to a server which then updates all clients with the updated price information when it changes. That way the data is sent to the cleint as fast as possible without constant http polling, and timers aren't necessary.
Of course, if the source of the data is a calculation within the JavaScript itself without having to get information from a server, then a mere modification of the above for your needs could suit.
Here's a jsfiddle to play around with.
I think this code help you
<script src="//code.jquery.com/jquery-1.12.0.min.js"></script>
<div class="test" id="test" onChange="setTitle(this)" title="testing...">Test1</div>
<script type="text/javascript">
$('#test').bind("DOMSubtreeModified",function(){
$('#test').attr('title',$('#test').html());
});
// Run below code in your console to change your div value
//$(".test").html("test2");
</script>
First run above code in you browser. and check tooltip will be 'testing...'.
Then run
$(".test").html("test2");
In your browser console to change your div html and then check your tooltip again. you will see the exact text of div.
Related
I am trying to write a ToDoList with JavaScript.
I have an input-element. Whenever I type something and press enter, it creates a new fieldset(in my example its a fieldset but it can also be a Div) with the class name ".fieldListClass" and a P-Tag as a child of fieldset. the P-tag innerHTML is the the value of input. I used Click-EventListener for that.
After each click, I assigned the query selector of all .fieldListClass to a nodeList "fieldListQuery". I even converted this nodeList into an Array but no result.
Now I want to create an addEventListner but outside the previous one. it should be a new one. And It should be a click-EventListener for all fieldListQuery which where created inside the previous function.(this part is at the bottom of my code)
When I click on it something should happen like removing the current target etc. But it wont work because outside the function it always says that this variable is undefined. I don't get it because I declared it global outside of the function.
I don't want to use DOMNodeInserted or MutationObserver yet for detecting changes inside the DOM. Simple because the first one is not recommended anymore it and the last one I have no idea how to use it. Many people saying that this is not a safe way.
Any Help please?
let addDiv = document.createElement("div"); addDiv.id = "addDivId";
let listDiv = document.createElement("div"); listDiv.id = "listDivId";
let inputText = document.createElement("input"); inputText.id = "inputTextId";
let fieldList; // = document.createElement("fieldset");
let fieldDiv; // = document.createElement("div");
let fieldDivP; // = document.createElement("P");
let fieldListArr;
let fieldListQuery;
document.body.appendChild(addDiv);
addDiv.appendChild(inputText);
document.body.appendChild(listDiv);
inputText.addEventListener("keypress", event => {
if (event.key === "Enter") {
fieldList = document.createElement("fieldset");
fieldDiv = document.createElement("div");
fieldDivP = document.createElement("P");
listDiv.appendChild(fieldList);
fieldList.className = "fieldListClass";
fieldList.appendChild(fieldDiv);
fieldDiv.appendChild(fieldDivP);
fieldDivP.innerHTML = inputText.value;
fieldListQuery = document.querySelectorAll(".fieldListClass") ;
}
})
fieldListQuery.forEach(element => { // <- it say fieldListQuery is undefined.
fieldListQuery.addEventListener("click", e => {
e.currentTarget.innerHTML="test";
})
});
´´´
Since I offered critique of your approach, I thought it is only fair I at least try to offer you some code that accomplishes (on the overall level, in light of absence of much detail about your solution) something along of what you have.
First off, I think creating trees of elements through a script when other solutions are more viable, tends to show an anti-pattern. Your script is invariably loaded in the context of an HTML document, which may already contain a lot of useful markup -- including an input field (that you were creating with createElement). If the input field is a "constant" there is no need to waste code on creating it -- just put it in your markup.
Second, even for elements or hierarchies of elements that are created "on demand" -- as a reaction to an event or however else -- it typically is much more readable and manageable to use templates. As a fallback -- if template cannot be used for some reason -- using innerHTML to create entire element trees is actually an appealing and more readable option than a lot of "boilerplate" containing createElement, appendChild, etc.
Third, you should always try to see if you can have your interactive controls be part of a form. I won't go into all reasons to do so, but suffice to say it helps user agents that screen-read content and for other accessibility systems, to name one. There are exceptions to this rule, but I don't recall looking at code where a control should not be part of a form -- so the rule is a good one.
Here is a proof-of-concept bare-bones to-do application:
<html>
<head>
<script>
function submit_create_todo_item_form() {
const new_todo_fragment = document.getElementById("todo-item-template").content.cloneNode(true);
new_todo_fragment.querySelector(".body").textContent = document.forms[0].elements[0].value;
document.body.appendChild(new_todo_fragment);
}
</script>
<template id="todo-item-template">
<div class="todo-item">
<p class="body"></p>
</div>
</template>
</head>
<body>
<form action="javascript: submit_create_todo_item_form()">
<input>
</form>
</body>
<html>
Take note that I use textContent instead of innerHTML to create content for a to-do item's body. innerHTML invokes the HTML parser and unless you plan to be typing hypertext into that single line of input field, innerHTML only costs you extra for no clear benefit. If you need to interpret the value verbatim, textContent is instead exactly what's needed. So, approach your solution with that in mind.
I hope this is useful, I worked with what I thought I had.
JS:
var player = {
su11: 100,
su22: 1000,
}
function gLoop() {
$(".upgrade").each(function() {
var test = player.obj[$(this).attr("id")];
if(player.total >= test)
{
$(this).prop("disabled", false);
}
});
}
setInterval(gLoop, 50);
HTML:
<button id="su11" class="upgrade su"></button>
The current basic code I have is as above. In the html, each instance of the .upgrade class has an id of the format "su##", and the player has a series of values of the same name.
My main concern is how I am using the id to reference the corresponding value in player. Is there an issue with the code that is unrelated to that, or is that simply a very bad idea?
My main goal is a button that, when a value is greater than or equal to its cost, enable itself to be clicked. It would be checked periodically as part of the main game loop. If there's a better way to do this (and I'm almost sure there is), please do tell me; I'm still relatively new to JS/JQuery.
The ID tag is used for storing an unique identifier, which can be used to find the element (and no other elements) in the document. Don't store arbitrary information in this tag. It goes against the goal of the ID tag, and also provokes the situation that at a certain time there are multiple elements in the document with the same ID (in a case where multiple elements have the same information payload).
If you really want to connect data to an DOM element, the common way to do it would be to use an data-xx attribute with your element such as <element data-su="12">, which you could then read with player.object[$(this).data("su")].
Dynamically swapping BODY content using jQuery html function works as expected with 'static' content.
But if forms are being used, current state of inputs is lost.
The jQuery detach function, which should keep page state, seems to be blanking out the whole page.
The following code is the initial idea using jQuery html but of course the text input value will always empty.
function swap1( ) {
$("body").html('<button onclick="swap2();">SWAP2</button><input type="text" placeholder="swap2"/>');
}
function swap2( ) {
$("body").html('<button onclick="swap1();">SWAP1</button><input type="text" placeholder="swap1"/>');
}
With not knowing what form inputs there are, how would one swap in and out these forms in the BODY and keep track of the form states?
Demo of two text inputs which should keep state when they come back into the BODY:
https://jsfiddle.net/g7hksfne/3/
Edit: missunderstood use case. This covers saving the state while manipulating the DOM, instead of switching between different states.
Instead of replacing the <body>'s content by serializing and parsing HTML, learn how to use the DOM. Only replace the parts of the DOM you actually change, so the rest of it can keep its state (which is stored in the DOM).
In your case: you might want to use something like this:
function swap1( ) {
document.querySelector("button").onclick = swap2;
document.querySelector("button").textContent = "SWAP2";
document.querySelector("input").placeholder = "swap2";
}
function swap2( ) {
document.querySelector("button").onclick = swap1;
document.querySelector("button").textContent = "SWAP1";
document.querySelector("input").placeholder = "swap1";
}
<button onclick="swap1();">SWAP1</button><input type="text" placeholder="swap1"/>
(This is not optimized and should only serve as an example.)
Put the content you want to save in a node below <body>, like a simple ´` if you don't already have a container. When you want to save and replace the container, use something like:
var saved_container = document.body.removeChild(document.querySelector("#app_container");
// or document.getElementById/getElementsByClassName, depends on container
The element is now detached and you can add your secondary to document.body. When you want to get back, save the secondary content (without overwriting the first container of course), then reattach the primary content it with:
document.body.appendChild(savedContainer);
I am a beginner in HTML and I want to create a region on a HTML page where the values keep on changing. (For example, if the region showed "56" (integer) before, after pressing of some specific button on the page by the user, the value may change, say "60" (integer) ).
Please note that this integer is to be supplied by external JavaScript.
Efforts I have put:
I have discovered one way of doing this by using the <canvas> tag, defining a region, and then writing on the region. I learnt how to write text on canvas from http://diveintohtml5.info/canvas.html#text
To write again, clear the canvas, by using canvas.width=canvas.width and then write the text again.
My question is, Is there any other (easier) method of doing this apart from the one being mentioned here?
Thank You.
You can normally do it with a div. Here I use the button click function. You can do it with your action. I have use jquery for doing this.
$('.click').click(function() {
var tempText = your_random_value;
// replace the contents of the div with the above text
$('#content-container').html(tempText);
});
You can edit the DOM (Document Object Model) directly with JavaScript (without jQuery).
JavaScript:
var number = 1;
function IncrementNumber() {
document.getElementById('num').innerText = number;
number++;
}
HTML:
<span id="num">0</span>
<input type='button' onclick='IncrementNumber()' value='+'/>
Here is a jsfiddle with an example http://jsfiddle.net/G638z/
To save me a lot of work editing a number in when adding a document to a site I decided to use javascript to count the number of elements with a class doc .
I am two main problems:
There is trouble displaying the variable. I initially thought this was because I hadn't added function, however when I tried adding this the variable was still not displayed.
The elements with the class I want to count are on another page and I have no idea how to link to it. For this I have tried var x = $('URL: /*pageURL*/ .doc').length; which hasn't worked.
Essentially I want the total elements with said class name and this to be displayed in a span element.
Currently I have something similar to what's displayed below:
<script>
var Items = $('.doc').length;
document.getElementById("display").innerHTML=Items;
</script>
<span id="display"></span>
Found an example of something similar here where the total numbers of articles are displayed.
Edit:
#ian
This code will be added to the homepage, domain.net/home.html. I want to link to the page containing this documents, domain.net/documents.html. I've seen this done somewhere before and if I remember correctly they used url:domainname.com/count somewhere in their code. Hope this helps.
Here is a jQuery call to retrieve the url "./" (this page) and parse the resulting data for all elements with class "lsep" "$('.lsep', data)". You should get back a number greater than 5 or so if you run this from within your debug console of your browser.
$.get("./", function(data, textStatus, jqXHR)
{
console.log("Instances of class: " + $('.lsep', data).length)
});
One important thing to remember is that you will run into issues if the URL your are trying to call is not in the same origin.
Here's an updated snippet of code to do what you're describing:
$(document).ready(
function ()
{
//var url = "/document.html" //this is what you'd have for url
//var container = $("#display"); //this is what you'd have for container
//var className = '.data'; //this is what you'd have for className
var url = "./"; //the document you want to parse
var container = $("#question-header"); //the container to update
var className = '.lsep'; //the class to search for
$.get(url, function (data, textStatus, jqXHR) {
$(container).html($(className, data).length);
});
}
);
If you run the above code from your browser's debug console it will replace the question header text of "Counting classes on another page and displaying them" with the count of instances the class name ".lsep" is used.
First, you have to wait until the document is ready before manipulating DOM elements, unless your code is placed after the definition of the elements you manipulate, wich is not the case in your example. You can pass a function to the $ and it will run it only when the document is ready.
$(function () {
//html() allows to set the innerHTML property of an element
$('#display').html($('.doc').length);
});
Now, if your elements belongs to another document, that obviously won't work. However, if you have used window.open to open another window wich holds the document that contains the .doc elements, you could put the above script in that page, and rely on window.opener to reference the span in the parent's window.
$('#display', opener.document.body).html($('.doc').length);
Another alternative would be to use ajax to access the content of the other page. Here, data will contain the HTML of the your_other_page.html document, wich you can then manipulate like a DOM structure using jQuery.
$.get('your_other_page.html', function(data) {
$('#display').html($('.doc', data).length);
});