I'm trying to accomplish a live character counter for a text input field, but cannot seem to make it work. The onkeypress-function either go as undefined or is just called once when loading the page
Simply assigning the function with onkeypress=" " does not seem to work.
Additionally, I want to update the text of charcountLabel; which I cannot seem to do. Simply using 'document.getElementById' for updating its innerHTML does not work.
How do I correctly assign keypress-functions to html-elements in .ejs?
How do I access and update innerHTML of other elements?
See code below:
<input type="text" id="textContent" onkeypress="charcount">
// Should be live-updated with the length of input text above.
<span id="charcountLabel"> 0 </span>
<script>
function charcount() {
var characterCount = document.getElementById("textContent").innerText.length;
document.getElementById("charcountLabel").innerHTML = characterCount;
}
</script>
Here you are
<input type="text" id="textContent" onkeypress="charcount()">
<!-- Should be live-updated with the length of input text above. -->
<span id="charcountLabel">0</span>
<script>
function charcount() {
var characterCount = document.getElementById("textContent").value.length;
document.getElementById("charcountLabel").innerHTML = characterCount;
}
</script>
Use parenthesis () to call the function and replace innerText with value property.
Note that // is comment in Javascript, not in html where you should use <!-- your comment --> instead.
Last, it has nothing to do with ejs.
Related
I am writing a Javascript program that takes a users input text, then (pending a radio button check – lowerCase/UpperCase) converts the input text to either lowercase/upperCase and outputs the value back to the form.
Purely trying to learn on my own Javascript. I am moderately new (but savvy) to JS. Pretty solid on HTML, CSS, Java, but BRAND new with interacting with page elements.
I have dug around for two days to try and solve this. I have even checked out a few books at my local library. (Currently reading the text, Microsoft guide to CSS/HTML, and JS). What other books would you recommend in order to under JS more?
Here is the code below. Although I know one can use CSS in order to convert this and I have done this. I'm purely just wanting to figure out Javascript.
<!DOCTYPE html>
<html>
<head>
<title> Case Changer By: Elliot Granet</title>
<style>
function convert(){
var convertedText = document.test.input.value;
if(document.getElementById("lowerCase").checked = true){
var output = convertedText.toLowerCase();
}else {
output = convertedText.toUpperCase();
}
document.getElementById('outputText').value = output;
}
convert();
</head>
The rest -
<body>
<h3>Choose your Conversion method below:</h3>
<form action="getElementById">
<fieldset>
<input id="lowerCase" type="radio" name="case" value="lowerCase">Lower Case<br>
<input id ="upperCase" type="radio" name="case" value="upperCase">Upper Case<br><br>
</fieldset>
<fieldset>
<textarea id="inputText" name="input" form="inputText">Enter text here to be Converted...</textarea>
</fieldset><br>
<fieldset>
<textarea id ="outputText" name="output" form="outputText">Converted text will appear here...</textarea>
</fieldset>
<input type="button" value="Convert">
</form>
</body>
</html>
You need to make few changes to make this function work.
style is an invalid tag to put js code. You need to put it inside <script> tag
If you are writing this function inside header yo may come across error since before DOM is ready it will try to get value of textarea with id inputText.
document.getElementById(idName').value but not is right syntax to get the value of element using id
Attaching convert() with the button. So when you will click on button the function will execute.
5.document.getElementById("lowerCase").checked = true this is wrong.It mean that checkbox will get checked as = will assign the value . Instead you need to compare the value. So use == or ===
if you declare var output inside if loop it wont be available inside else. So you need to declare it outside the if-else loop
Hope this snippet will be useful
HTML
<input type="button" value="Convert" onclick="convert()">
JS
window.load =convert; // convert function will be called after window is ready
function convert(){
var output; //variable declaration outside if-else loop
var convertedText = document.getElementById('inputText').value; //document.getElementById
if(document.getElementById("lowerCase").checked == true){ // == comparision
output = convertedText.toLowerCase();
}
else {
output = convertedText.toUpperCase();
}
document.getElementById('outputText').value = output;
}
EXAMPLE
For some reasons I am trying to change functionality of submit button. I am facing problem in copying data from HTML tags to JS. The alert generated by following code prints "Undefined" not the data inside tag.
<html>
<body>
<input class="inputtext" id="email" name="email" type="text"></div>
<input value="Submit" name="v4l" id="login" class="inputsubmit" type="button" onclick="myFunction();return false">
<script>
function myFunction() {
var TestVar =document.getElementsByClassName('login').value;
alert(TestVar);
}
</script>
</body>
</html>
I know it can be done by form but I need it this way.
try
var TestVar = document.getElementById('email').value
alert(TestVar);
this will get value of text field
getElementsByClassName
^
See that s? Elements is plural. getElementsByClassName returns a NodeList (which is like an Array).
You have to either pick an index from it (foo[0]) or loop over it to get the values.
That said, you don't actually have any elements that are a member of the login class, so it is going to return a Node List of zero length.
You do have an element with id="login", so maybe you should use getElementById instead.
There doesn't seem much point in reading the value from an element that you've hard coded the value for. You might actually want to be using document.getElementById('email')
couldn't find a specfic answer elsewhere. I'm totally new to JS and trying to pull a value out of a form and write it to the page. The result when I try to write ProductName is undefined, and when I try to write ProductNameElement is null. I'm sure it's to do with the form values being empty when the page loads but not sure after that...
<script>
var ProductNameElement = document.getElementById("ProductName");
var ProductName = ProductNameElement.value;
function showname(){
document.write(ProductName);
}
</script>
<h2>Revenues</h2>
<div class="number">Product Name: <input type="text" id="ProductName" value=""></input></div>
<input type="button" value"showname" onclick="showname();"></input>
You are running the first two lines of your script too early BEFORE the elements in your page have been parsed and placed into the DOM. Because of that, the ProductName element doesn't exist yet when you're trying to find it with document.getElementById("ProductName");.
Place your script right before the </body> tag and then all your page elements will be available when you run your script. Or, just put all your code in the showname function that isn't called until the click event.
function showname(){
var ProductNameElement = document.getElementById("ProductName");
var ProductName = ProductNameElement.value;
document.write(ProductName);
}
And, as others have said, using document.write() after the documented has been loaded will cause the existing document to be cleared and a new empty document will be created. This is pretty much never what you want. If you're just doing this for debugging, use console.log(ProductName) and look at the debug console.
You'll have to get the element and the value inside the function, otherwise they aren't available, and the change of the value isn't caught
<script>
function showname(){
var ProductNameElement = document.getElementById("ProductName");
var ProductName = ProductNameElement.value;
document.write(ProductName);
}
</script>
<h2>Revenues</h2>
<div class="number">
Product Name: <input type="text" id="ProductName" value="" />
</div>
<input type="button" value"showname" onclick="showname();" />
FIDDLE
And inputs are self closing, and you should stop using document.write, it will overwrite the entire document and remove everything that is currently there !
I'm just trying to do this from the chrome console on Wikipedia. I'm placing my cursor in the search bar and then trying to do document.activeElement.innerHTML += "some text" but it doesn't work. I googled around and looked at the other properties and attributes and couldn't figure out what I was doing wrong.
The activeElement selector works fine, it is selecting the correct element.
Edit: I just found that it's the value property. So I'd like to change what I'm asking. Why doesn't changing innerHTML work on input elements? Why do they have that property if I can't do anything with it?
Setting the value is normally used for input/form elements. innerHTML is normally used for div, span, td and similar elements.
value applies only to objects that have the value attribute (normally, form controls).
innerHtml applies to every object that can contain HTML (divs, spans, but many other and also form controls).
They are not equivalent or replaceable. Depends on what you are trying to achieve
First understand where to use what.
<input type="text" value="23" id="age">
Here now
var ageElem=document.getElementById('age');
So on this ageElem you can have that many things what that element contains.So you can use its value,type etc attributes. But cannot use innerHTML because we don't write anything between input tag
<button id='ageButton'>Display Age</button>
So here Display Age is the innerHTML content as it is written inside HTML tag button.
Using innerHTML on an input tag would just result in:
<input name="button" value="Click" ... > InnerHTML Goes Here </input>
But because an input tag doesn't need a closing tag it'll get reset to:
<input name="button" value="Click" ... />
So it's likely your browsers is applying the changes and immediatly resetting it.
do you mean something like this:
$('.activeElement').val('Some text');
<input id="input" type="number">
document.getElementById("input").addEventListener("change", GetData);
function GetData () {
var data = document.getElementById("input").value;
console.log(data);
function ModifyData () {
document.getElementById("input").value = data + "69";
};
ModifyData();
};
My comments: Here input field works as an input and as a display by changing .value
Each HTML element has an innerHTML property that defines both the HTML
code and the text that occurs between that element's opening and
closing tag. By changing an element's innerHTML after some user
interaction, you can make much more interactive pages.
JScript
<script type="text/javascript">
function changeText(){
document.getElementById('boldStuff').innerHTML = 'Fred Flinstone';
}
</script>
HTML
<p>Welcome to Stack OverFlow <b id='boldStuff'>dude</b> </p>
<input type='button' onclick='changeText()' value='Change Text'/>
In the above example b tag is the innerhtml and dude is its value so to change those values we have written a function in JScript
innerHTML is a DOM property to insert content to a specified id of an element. It is used in Javascript to manipulate DOM.
For instance:
document.getElementById("example").innerHTML = "my string";
This example uses the method to "find" an HTML element (with id="example") and changes the element content (innerHTML) to "my string":
HTML
Change
Javascript
function change(){
document.getElementById(“example”).innerHTML = “Hello, World!”
}
After you clicked the button, Hello, World! will appear because the innerHTML insert the value (in this case, Hello, World!) into between the opening tag and closing tag with an id “example”.
So, if you inspect the element after clicking the button, you will see the following code :
<div id=”example”>Hello, World!</div>
That’s all
innerHTML is a DOM property to insert content to a specified id of an element. It is used in Javascript to manipulate DOM.
Example.
HTML
Change
Javascript
function FunctionName(){
document.getElementById(“example”).innerHTML = “Hello, Kennedy!”
}
On button Click, Hello, Kennedy! will appear because the innerHTML insert the value (in this case, Hello, Kennedy!) into between the opening tag and closing tag with an id “example”.
So, on inspecting the element after clicking the button, you will notice the following code :
<div id=”example”>Hello, Kennedy!</div>
Use
document.querySelector('input').defaultValue = "sometext"
Using innerHTML does not work on input elements and also textContent
var lat = document.getElementById("lat").value;
lat.value = position.coords.latitude;
<input type="text" id="long" class="form-control" placeholder="Longitude">
<button onclick="getLocation()" class="btn btn-default">Get Data</button>
Instaed of using InnerHTML use Value for input types
I'd like to refer to a variable ("special") in field later in the same script. I've gotten the variable to display with alert boxes and document.write, but don't now how to make to apply its value to the value field in
var special=(10000-health);
var health=(100);
<input style="background:#FF7777;" readonly="readonly" type="text" value="special" id="special" />
this just writes "special" to the box, when I would like the value instead.
You have to set the value explicitly:
document.getElementById('special').value = special;
Note: You can only access the element after it was parsed in the DOM. To be sure, you can insert this part of the script after the element in the HTML. Often JavaScript code is added just before the closing body tag or is only executed when the load event fires. For more information, see Where to place JavaScript in a HTML file.
Update: Here is an example:
<body>
<input style="background:#FF7777;" readonly="readonly" type="text" value="special" id="special" />
<script type="text/javascript">
var health = 100;
var special = 10000 - health;
document.getElementById('special').value = special;
</script>
</body>
References: getElementById, DOM
MDC's JavaScript Guide is also worth reading.
document.getElementById('special').value = special;
you have to use some kind of DOM manipulation. One of the more popular libraries is JQuery.
using jQuery you'd write something like
$('#special').val(special);
var input = document.getElementById('special');
input.value = special;