Edit: Just confirming: I want what the user typed to be saved so that when he reloads/leaves the webpage and comes back what he wrote earlier is still there.
I tried using cookies but it only put one line of Default(variable) when I reloaded the page. Im trying to get it to work with localStorage now but it sets the textarea to "[object HTMLTextAreaElement]" or blank when I reload. I read that this error can be caused by forgetting to add the .value after getElementById() but I did not make this mistake. I am hosting and testing the webpage on Github(pages). What am I doing wrong? here is the code(ignore the comments also it might not work in jsfiddle bc it localstorage didn't work there for me):
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>le epic web page</title>
</head>
<body><!--
= "\n"-->
<textarea id="txt" rows="4" cols="50" oninput="save();"></textarea>
<script>
var Default="P1 Homework: \nP2 Homework: \nP3 Homework: \nP4 Homework: \n";
if(localStorage.getItem("P") == ""){
document.getElementById("txt").value=Default;
localStorage.setItem("P")=Default;
}else{
document.getElementById("txt").value=localStorage.getItem("P");
}
//update cookie (called when typed)
function save(){
var txt=document.getElementById("txt").value;
//txt=txt.replace(/\r\n|\r|\n/g,"</br>");
localStorage.setItem("P",txt);//set cookie to innerHTML of textArea, expires in 1 day
}
//when page closed/reloaded
window.onbeforeunload = function(){
localStorage.setItem("P",txt);//update cookie when page is closed https://stackoverflow.com/a/13443562
}
</script>
</body>
</html>
When you are exiting the page, you are referencing the text element and storing that in localstorage. Since localStorage is a string it converts the html element reference into the text you see.
window.onbeforeunload = function(){
localStorage.setItem("P",txt);
}
You are doing it correctly with save, so just call save with the beforeunload event
window.addEventListener('beforeunload', save);
Another bug in the code is the line
if(localStorage.getItem("P") == ""){
when localStorage is not set, it returns null. So the check would need to be a truthy check ( or you can check for nullv)
if(!localStorage.getItem("P")){
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>le epic web page</title>
</head>
<body>
<textarea id="txt" rows="4" cols="50" oninput="save();"></textarea>
</body>
<script>
const Default =
"P1 Homework: \nP2 Homework: \nP3 Homework: \nP4 Homework: \n";
if (
localStorage.getItem("P") === "" ||
localStorage.getItem("P") === null ||
localStorage.getItem("P") === undefined
) {
localStorage.setItem("P", Default);
} else {
let currentValue = document.getElementById("txt");
currentValue.value = localStorage.getItem("P");
}
function save() {
let txt = document.getElementById("txt").value;
localStorage.setItem("P", txt);
}
window.onbeforeunload = function () {
let txt = document.getElementById("txt").value;
localStorage.setItem("P", txt);
};
</script>
</html>
Related
I have a name input on 1.html.
I need to call a function where the input will be stored after completion, and when the person clicks ~next~ to go to the next page (2.html), whatever was stored appears there.
Example:
~1.html~
What's your name?
~input~ John ~input~
~2.html~
Hi, John! How can i help you?
I know i can use Session Storage to do it, but i'm not sure on how to proceed.
Here's what i have:
1.html
<p>"Whats Your Name?"</p>
<input id="your-name-input" type="text">
<a href="2.html">
<button id="next-button">Next</button>
<script>
nextButton = document.getElementById("next-button);
nextButton.addEventListener("click", () => {
var name = document.getElementbyId("your-name-input").value;
if(name !== "") {
sessionStorage.setItem("name", name);
} else {
alert("Please fill yout name")
});
</script>
And then, on 2.html i have:
<p id="user-name"></p>
What i'm trying to do, is to put inside the <p>, the following greeting:
Hi (name.value), how can i help you?
How can i call a function that loads the name value on the 2.html page when the page loads?
The below code should work. There are a few things missing in your code, not sure if you copied everything in.
In either case, the below works for me. You just need to update the link in the window.location = syntax. When you do that, it will take your stored value to the new page in the same tab, and display it using the script code in 2.html.
Code in 1.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1" />
<title>Your name test</title>
</head>
<body>
<p>Whats Your Name?</p>
<input id="your-name-input" type="text">
<button id="next-button">Next</button>
<script>
const nextButton = document.getElementById("next-button");
const input = document.getElementById("your-name-input");
nextButton.addEventListener("click", () => {
const name = input.value;
if(name !== "") {
sessionStorage.setItem("name", name);
window.location = "<link to your 2.html file>";
} else {
alert("Please fill your name")
}
});
</script>
</body>
<footer>
</footer>
</html>
Code in 2.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1" />
<title>See, it works</title>
</head>
<body>
<p id="user-name"></p>
<script>
const displayText = document.getElementById("user-name");
const storedValue = sessionStorage.getItem("name");
console.log(storedValue);
window.addEventListener("load", () => {
displayText.innerHTML = "Hi " + storedValue;
})
</script>
</body>
<footer>
</footer>
</html>
Original ans to original question:
You could use an addEventListener with an IF statement for your 'next' button and then the code you already have for localStorage.
Depending on what you need from your page, you could also use sessionStorage - that one doesn't save the input forever so might save, albeit limited, space on your user's computer.
I don't see the HTML for your button yet. But assuming you have it, here's an option for the rest of your code in 1.html.
Inside 1.html script tag:
nextButton = document.getElementById("yourButtonID");
nextButton.addEventListener("click", () => {
var name = document.getElementById("your-name-input").value;
if(name !== "") { // if input is not empty
localStorage.setItem("name", name); // set the value in localStorage
} else {
alert("Please fill your name")} // else, display an alert (if you like)
});
I want for the user to click a button which leads to another page. Depending on what button the user clicks, the page content should look different despite being on the same page. A simplified example is below:
Starting page html code:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
Click Here
Click Here
<script src="script.js"></script>
</body>
</html>
second-page.html code:
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<p id="content-id">*CONTENT SHOULD BE LOADED HERE BASED OFF BUTTON CLICKED*</p>
<script src="script.js"></script>
</body>
</html>
script.js code:
function changeContent(n) {
document.getElementById("content-id").innerHTML = n;
}
The above code does not work. I'm guessing the browser doesn't see the content-id on the first page and fails to change anything before loading the second page. Any way to reference the right id on the right page using JavaScript (no jQuery) when the new page is loaded?
Short answer: there are several approaches, the easier that comes to mind is to use localStorage if you're dealing with same origin pages
What you need is to have user information available across multiple pages. So, unlike sessionStorage, localStorage allows to store data and save it across browser sessions:
localStorage is similar to sessionStorage, except that while localStorage data has no expiration time, sessionStorage data gets cleared when the page session ends — that is, when the page is closed.
To use it, consider adapting your javascript of first page:
function changeContent(n) {
localStorage.setItem('optionChosen', n);
}
Then retrieve it in the second page's javascript.
var opt = localStorage.getItem('optionChosen')
var content = document.querySelector('#content-id')
if (opt == null) console.log("Option null")
if (opt === 'Option One') content.innerText = "Foo"
if (opt === 'Option Two') content.innerText = "Bar"
Edited -
Added 3 working examples that can be copy and pasted.
Problem -
Display content on a new view based on the button clicked to get to that view.
Approach -
You can store the value of ID in the browser to help identify the content that should be displayed in many ways. I will show you three working examples.
Notes -
I am over complicating this a little to show you how you might make this work since I do not know the exact circumstances you are working with. You should be able to use this logic to refactor for your requirements. You will find the following 3 solutions below.
1. Using GET Params
Uses the GET params in the URL to help you track necessary changes in your view.
2. Using Session Storage
A page session lasts as long as the browser is open, and survives over page reloads and restores.
Opening a page in a new tab or window creates a new session with the value of the top-level browsing context, which differs from how session cookies work.
Opening multiple tabs/windows with the same URL creates sessionStorage for each tab/window.
Closing a tab/window ends the session and clears objects in sessionStorage.
3. Using Local Storage
The difference between localStorage and sessionStorage is the time the data persists. LocalStorage spans multiple windows and lasts beyond the current session.
The memory capacity may change by browser.
Similar to cookies, localStorage is not permanent. The data stored within it is specific to the user and their browser.
Solutions -
Working Examples - (Copy and paste any of the below solutions into an HTML file and they will work in your browser.)
Using GET Params
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<script type="text/javascript">
let currentURL = window.location.href.split("?")[0];
function appendParams(val) {
if (val === "a") {
window.location.assign(currentURL + "?id=a");
}
if (val === "b") {
window.location.assign(currentURL + "?id=b");
}
}
</script>
<title>Working Example</title>
</head>
<body>
<button onclick="appendParams('a')">Click Here</button>
<button onclick="appendParams('b')">Click Here</button>
<p id="replace-id"></p>
</body>
</html>
<script type="text/javascript">
let url_str = window.location.href;
let url = new URL(url_str);
let search_params = url.searchParams;
let id = search_params.get("id");
document.getElementById("replace-id").id = id;
let ContentOne = "Some text if id is A";
let ContentTwo = "Some text if id is B";
if (id === "a") {
document.getElementById("a").innerHTML = ContentOne;
}
if (id === "b") {
document.getElementById("b").innerHTML = ContentTwo;
}
</script>
Using Session Storage
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<script type="text/javascript">
sessionStorage.setItem("id", "default");
function addSessionStorage(val) {
sessionStorage.setItem("id", val);
updateContent();
}
function updateContent() {
let id = sessionStorage.getItem("id");
let ContentOne = "Some text if id is A";
let ContentTwo = "Some text if id is B";
if (id === "a") {
document.getElementById("replace-content").innerHTML =
ContentOne;
}
if (id === "b") {
document.getElementById("replace-content").innerHTML =
ContentTwo;
}
}
</script>
<title>Working Example</title>
</head>
<body>
<button onclick="addSessionStorage('a')">Click Here</button>
<button onclick="addSessionStorage('b')">Click Here</button>
<p id="replace-content">Default Content</p>
</body>
</html>
Using Local Storage
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<script type="text/javascript">
localStorage.setItem("id", "default");
function addLocalStorage(val) {
localStorage.setItem("id", val);
updateContent();
}
function updateContent() {
let id = localStorage.getItem("id");
let ContentOne = "Some text if id is A";
let ContentTwo = "Some text if id is B";
if (id === "a") {
document.getElementById("replace-content").innerHTML =
ContentOne;
}
if (id === "b") {
document.getElementById("replace-content").innerHTML =
ContentTwo;
}
}
</script>
<title>Working Example</title>
</head>
<body>
<button onclick="addLocalStorage('a')">Click Here</button>
<button onclick="addLocalStorage('b')">Click Here</button>
<p id="replace-content">Default Content</p>
</body>
</html>
I have a VERY BASIC knowledge of javascript and I was looking forward to learn some conditional statement in javascript. So I went on and entered this code in a HTML file called "index.html":
<!DOCTYPE html>
<html>
<head>
<title>A sample webpage</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>
And the result that came was completely normal. A title called "Sample Webpage" appeared.
But the next code what I entered created problems in the result,
var myNumber = window.prompt("Enter number: ");
parseFloat(myNumber);
document.write(myNumber);
The result comes as expected.
if (myNumber > 15) {
document.write(<p>Good! You've passed! </p>);
}
else {
document.write(<p>You failed! Try again next time.</p>);
}
But when I add this if statement which gives an output based on the user's input, I get a blank page. I don't understand what is the reason for this. Are there any problems in the syntax?
It also seems to me that it doesn't execute the first part of the code I've written, it completely wants all of the code. I feel this is normal but doesn't it have to actually execute the "document.write" code?
Way I see it, you need to quote your strings in document.write(string).
like this:
if (myNumber > 15) {
document.write("<p>Good! You've passed! </p>");
}
else {
document.write("<p>You failed! Try again next time.</p>");
}
I hope it is useful for you. Thank you.
document.write takes a string as argument. You pass it HTML.
Just change
document.write(<p>Good! You've passed! </p>);
to
document.write('<p>Good! You've passed! </p>');
to make it work. A better approach is to add
<p id="message"></p>
to the page and where you have
document.write('<p>Good! You've passed! </p>');
you can use
document.getElementById('message').textContent='Good! You've passed!';
document.getElementById("myButton").addEventListener('click', function() { // when clicked
let myNumber = window.prompt("Enter number: ");
myNumber = parseFloat(myNumber); // convert to number from string
document.getElementById('number').textContent = myNumber;
const msg = document.getElementById('number'); // output container
if (myNumber > 15) {
msg.textContent = 'Good! You\'ve passed!' // escaping the quote
}
else {
msg.textContent = 'You failed! Try again next time.';
}
});
// above can be written using a so called ternary:
// msg.textContent = myNumber > 15 ? 'Good! You\'ve passed!' : 'You failed! Try again next time.'
<!DOCTYPE html>
<html>
<head>
<title>A sample webpage</title>
</head>
<body>
<p id="number"></p>
<p id="message"></p>
<button type="button" id="myButton">Did you pass?</button>
<script src="script.js"></script>
</body>
</html>
I am trying to retain data in a localstorage after reload but it is not working
this is my attempt
<script>
window.onbeforeunload = function() {
localStorage.setItem(name, $('#inputName').val());
}
window.onload = function() {
var name = localStorage.getItem(name);
if (name !== null) $('#inputName').val(name);
alert(name);
}
</script>
<html>
<body>
<input type="text" id="inputName" placeholder="Name" required>
</body>
</html>
on refreshing the page after entering data on the form it keeps alerting null. kindly assist
In your onbeforeunload, name is the name of the window (because you haven't given it any other value, and browsers have a global name property which is the name of the window — it's usually blank).
In this line:
var name = localStorage.getItem(name);
...it's undefined, because of the var name.
You need to use a proper name, for instance:
window.onbeforeunload = function() {
localStorage.setItem("your-setting-name", $('#inputName').val());
};
window.onload = function() {
var name = localStorage.getItem("your-setting-name");
if (name !== null) $('#inputName').val(name);
alert(name);
};
Also note charlietfl's oint that if you don't want to alert null on the first visit to the page, you need to put the alert in the body of the if:
window.onload = function() {
var name = localStorage.getItem("your-setting-name");
if (name !== null) {
$('#inputName').val(name);
alert(name);
}
};
Otherwise, it'll alert null on the first visit and then whatever the last value was otherwise.
(Also note that I've added some missing ;. Automatic Semicolon Insertion will add these particular ones, but it's an error-correction mechanism, so I'd advise not relying on it.)
Other issues:
You're using jQuery functions, but haven't shown any script tag including jQuery on the page.
You have the closing </html> tag before the <input ...> tag.
Here's a fiddle with the above fixed (can't use Stack Snippets with local storage): https://jsfiddle.net/un86not0/ Full working page:
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge">
<title>Example</title>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script>
window.onbeforeunload = function() {
localStorage.setItem("your-setting-name", $('#inputName').val());
};
window.onload = function() {
var name = localStorage.getItem("your-setting-name");
if (name !== null) {
$('#inputName').val(name);
alert(name);
}
};
</script>
<input type="text" id="inputName" placeholder="Name" required>
</body>
</html>
The variable name haven't been initiated yet you already used it as a value reference. Maybe it wasn't working well because of that?
Here in this solution, you can separately reference the local storage item without using the variable name which might have caused it not to work.
<script>
window.onbeforeunload = function() {
localStorage.setItem('myItem', $('#inputName').val());
}
window.onload = function() {
var name = localStorage.getItem('myItem');
if (name !== null) $('#inputName').val(name);
alert(name);
}
</script>
I made a button click counter for a website using some JavaScript.
The counter works well, but now I'm stuck in making the saving of the count. You know, if I click the button 3 times, the text says 3 Times. But I want to save that value so if the user refreshes the page, it should display 3 Times again.
I knew of using localStorage, I followed a simple tutorial and applied it to my code, but it does not seem to be working. When I run the page in Microsoft Edge and see the Debug page (F12), the console throws an error that says: Unable to get property 'getItem' of undefined or null reference. I searched in other posts but no one of these could solve my problem. It seems to be stuck when retrieving the value in localStorage.
This is my code:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Increment count when button is clicked</title>
</head>
<body>
<input type="button" value="Registrar" id="countButton" />
<input id="ocityField" type="text" value="" placeholder="Ciudad de Origen"/>
<input id="cityField" type="text" value="" placeholder="Ciudad de participación"/>
<input id="name" type="text" value="" placeholder="Nombre"/>
<p>Personas Registradas: <span id="displayCount">0</span></p>
<script type="text/javascript">
var count = 0;
var button = document.getElementById("countButton");
var display = document.getElementById("displayCount");
var textbox = document.getElementById("ocityField");
var textboxa = document.getElementById("cityField");
var textboxb = document.getElementById("name");
if(window.localStorage.getItem('count')){
var savedcount = window.localStorage.getItem('count');
count = window.localStorage.getItem('count');
}else{
count = 0;
}
display.innerHTML = count;
button.onclick = function(){
var mystring = textbox.value;
var mystring2 = textboxa.value;
var mystring3 = textboxb.value;
if(!mystring.match(/\S/) || !mystring2.match(/\S/) || !mystring3.match(/\S/)) {
alert ('Empty value is not allowed');
return false;
} else {
count++;
window.localStorage.setItem('count', count);
display.innerHTML = count;
textbox.value = "";
textboxa.value = "";
textboxb.value = "";
return true;
}
}
</script>
</body>
</html>
I tried using window.localStorage and just localStorage but no one did work.
May be that you use the IE browser does not support localStorage，The code can run in Chrome49.
Can I Use localStorage, here you can check what browser supports localStorage with version numbers.
Alternate way to store data on client side is cookies if localStorage doesn't supported by browser.
You can also use third party plugins like Modernizer, to check whether browser supports or not.
Modernizr.localstorage if it evaluate to true the browser supports localStorage.
Following example demonstrates localStorage and cookies depending on browser compatibility. uses Modernizer and jQuery
codepen