Develop Reference

How to change value inside textfield HTML

How can I change the value inside my Revenue textfield by subtracting the Cost of Good value from the Sales Price value? I have attached an image of what it looks like currently, but I want to change whats displayed inside my Revenue field after I edit the previous 2 text fields. I have also attached my code.
See attached image
<div class="product-section">
<h3>
<b>{{ product.productLabel }}</b>
</h3>
<label for="sales-price">Sales Price: </label>
<br>
<input
type="text"
[(ngModel)]="product.salesPrice"
name="sales-label"
placeholder="Enter Sales Price"
/>
<p></p>
<label for="cogs">Cost of Good: </label>
<br>
<input
type="text"
[(ngModel)]="product.cogs"
name="cogs-label"
placeholder="Enter Cogs"
/>
<p></p>
<label for="rev">Revenue: </label>
<br>
<input
type="text"
[(ngModel)]="product.rev"
name="rev-label"
readonly
/>
</div>

Add (keyup)="getRev()" to your Sales Price and Cost of Goods inputs.
<div class="product-section">
<h3>
<b>{{ product.productLabel }}</b>
</h3>
<label for="sales-price">Sales Price: </label>
<br>
<input
type="text"
[(ngModel)]="product.salesPrice"
(keyup)="getRev()"
name="sales-label"
placeholder="Enter Sales Price"
/>
<p></p>
<label for="cogs">Cost of Good: </label>
<br>
<input
type="text"
[(ngModel)]="product.cogs"
(keyup)="getRev()"
name="cogs-label"
placeholder="Enter Cogs"
/>
<p></p>
<label for="rev">Revenue: </label>
<br>
<input
type="text"
[(ngModel)]="product.rev"
name="rev-label"
readonly
/>
</div>
Then add a function to your component's typescript file to handle the revenue calculation.
getRev() {
this.product.rev = this.product.cogs - this.product.salesPrice;
}

Can you post the body of getRev()? And, take the quotes away from getRev() so that it calls the function instead of sets the value as the literal string 'getRev()'
Edit:
Is there a way to just subtract the cogs value from my sales value?
Yes, you could use an onchange handler. Here is an example, assuming you set the ID of the three elements as 'cogs', 'sales', and 'revs':
const cogs = document.getElementById('cogs');
const sales = document.getElementById('sales');
const revs = document.getElementById('revs');
cogs.addEventListener('input', (event) => {
const salesNumber = Number(sales.value);
const cogsNumber = Number(cogs.value);
const difference = salesNumber - cogsNumber;
revs.value = difference;
});

how to get set of input boxes values using getElemntById?

I have set of input boxes to add names and designaions.and iwant to print those in a <p> tag when user click print button. how to proceed.
<div class="form-group">
<label for="inputRegNo" >Name & Designation<span style="color:#c0392b;padding-left:5px;">*</span></label>
<div class="form-group">
<input required type="text" name="fname[]" class="fname" onkeyUp="document.getElementById('refa5').innerHTML = this.value" placeholder="Name" />
<input required type="text" name="lname[]" placeholder="Designation" />
</div>
</div>
<div class="form-group">
<label for="inputRegNo" ></label>
<div class="form-group">
<input type="text" name="fname[]" placeholder="Name" class="fname" onkeyUp="document.getElementById('refa5').innerHTML = this.value" />
<input type="text" name="lname[]" placeholder="Designation" />
</div>
</div>
print
<div>
<label>Name & Designation</label>
<p id="refa5"> - </p>
</div>

its looks you are new in javascript.. it's simple give the name to all the input field like
<input type="text/checkbox" name="txtName">
and in javascript you can access this field value by
<script type="text/javascript">
var name = document.getElementsByName("txtName");
</script>
if you wish to print the element on button click simply specify their click event on javascript like
function onClick() {
alert("helo from click function");
}
and then on button ..
<input type="button" onclick="onClick()">

w3schools is a great resource for this. Here is some example code on how to do this :
<button onclick="myFunction()">Click me</button>
<input id="inputID"></input>
<p id="demo"></p>
<script>
function myFunction() {
var inputID = document.getElementById("inputID").value;
document.getElementById("demo").innerHTML = inputID;
}
</script>
What the code above does is it takes the value of an input, then it sets the innerHTML of a <p> element to it. You can obviously do this with other things like <h1> elements as well.

JavaScript - set form input attribute in 'for' loop

This is my first real-world JavaScript project. Please be kind...
I'm creating a form with required fields. With JavaScript, I am collecting the required fields as objects in an Array, each object having the properties "object" (the HTML objects themselves, from which I can get object.id and object.value) "description" (to display to users) and "error" (the HTML objects beneath each input field where corresponding validation errors appear).
Then I have a function (to be used onBlur, for instant feedback) that checks to see if the value of the field is null, and if so, it displays the validation error beneath the corresponding field.
I'm trying to set the onblur attribute for each input field using a FOR loop that runs through the array of required fields. I have a setAttribute statement that works perfectly if I create an individual statement for each object in the Array, individually. But as soon as I change it to a FOR loop, the onblur event for ANY field pops up the validation error for the FIRST input field, only. This has got to be a freshman mistake, but I've searched high and low and rewritten this thing ten different ways and can't make it work with a loop...
I put my code in a Fiddle so you can see it -- but it doesn't actually work in the fiddle, only in my local dev environment (maybe that indicates another problem?). Here's the code:
//create array with constructor to identify all required fields
var allRequired = [];
function RequiredField(theID, theDescription) {
this.object = document.getElementById(theID);
this.description = theDescription;
this.error = document.getElementById("error-" + theID);
allRequired.push(this);
}
var fieldFname = new RequiredField("fname", "First Name");
var fieldLname = new RequiredField("lname", "Last Name");
var fieldEmail = new RequiredField("email", "Email");
var fieldPhone = new RequiredField("phone", "Phone");
var fieldRole = new RequiredField("role", "Desired Role");
var fieldPortfolio = new RequiredField("portfolio", "Portfolio/Website URL");
function requireField(theDescription, theValue, theError) {
if (theValue === "") {
theError.innerHTML = "<p>" + theDescription + " is required.</p>";
} else {
theError.innerHTML = "";
}
} //end function
for (i = 0; i < allRequired.length; i++) {
allRequired[i].object.setAttribute("onBlur", "requireField(allRequired[i].description, allRequired[i].object.value, allRequired[i].error);");
}
/* THIS WORKS IN MY LOCAL DEV ENVIRONMENT...
allRequired[0].object.setAttribute("onBlur", "requireField(allRequired[0].description, allRequired[0].object.value, allRequired[0].error);");
allRequired[1].object.setAttribute("onBlur", "requireField(allRequired[1].description, allRequired[1].object.value, allRequired[1].error);");
allRequired[2].object.setAttribute("onBlur", "requireField(allRequired[2].description, allRequired[2].object.value, allRequired[2].error);");
allRequired[3].object.setAttribute("onBlur", "requireField(allRequired[3].description, allRequired[3].object.value, allRequired[3].error);");
allRequired[4].object.setAttribute("onBlur", "requireField(allRequired[4].description, allRequired[4].object.value, allRequired[4].error);");
allRequired[5].object.setAttribute("onBlur", "requireField(allRequired[5].description, allRequired[5].object.value, allRequired[5].error);");
*/
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form name="form-careers" id="form-careers" action="form-process.php" enctype="multipart/form-data" onsubmit="return validateForm()" method="post">
<div class="form_labels">
<p>
<label for="fname">First Name:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="text" name="fname" id="fname" required />
</p>
<div class="error" id="error-fname"></div>
</div>
<div class="form_labels">
<p>
<label for="lname">Last Name:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="text" name="lname" id="lname" required />
</p>
<div class="error" id="error-lname"></div>
</div>
<div class="form_labels">
<p>
<label for="email">Email:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="email" name="email" id="email" required />
</p>
<div class="error" id="error-email"></div>
</div>
<div class="form_labels">
<p>
<label for="phone">Phone:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="tel" name="phone" id="phone" placeholder="###-###-####" pattern="\d{3}[\-]\d{3}[\-]\d{4}" required />
</p>
<div class="error" id="error-phone"></div>
</div>
<div class="form_labels">
<p>
<label for="role">Desired Role:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="text" name="role" id="role" required />
</p>
<div class="error" id="error-role"></div>
</div>
<div class="form_labels">
<p>
<label for="portfolio">Portfolio/Website:</label>
</p>
</div>
<div class="form_inputs">
<p>
<input type="url" name="portfolio" id="portfolio" placeholder="http://" pattern="[a-z0-9.-]+\.[a-z]{2,63}$" required />
</p>
<div class="error" id="error-portfolio"></div>
</div>
<div class="clearboth"></div>
<input type="hidden" name="formtype" id="formtype" value="careers">
<div class="form_labels">
<p> </p>
</div>
<div class="form_inputs">
<a href="#">
<input type="submit" value="Submit" class="btn-red">
</a>
</div>
</form>
If someone would help point me in the right direction I would really appreciate it.

Code
for (i = 0; i < allRequired.length; i++) {
allRequired[i].object.setAttribute("onBlur", "requireField(allRequired[i].description, allRequired[i].object.value, allRequired[i].error);");
}
sets onblur event with value like requireField(allRequired[i].description.
So - what is it - i? No one knows.
Proper code is:
for (i = 0; i < allRequired.length; i++) {
allRequired[i].object.setAttribute("onBlur", "requireField(allRequired[" +i + "].description, allRequired[" + i + "].object.value, allRequired[" + i + "].error);");
}
See? I get real i value for each iteration.

As u_mulder said concat problem.
As for code I suggest to look up factory functions. It's more natural javascript then constructor.

comment system using angular js

I am a beginner and i have a problem in creating a review form using angular js. I've got the input value in an empty array. but i don't know were to push that fetched content so that it will be displayed in the web page(inside the blockquote).please give a simple and understandable answer
HTML
<section class="container" ng-controller="storeController as store">
<div class="row">
<div class="col-md-12" style="margin-top:100px;" ng-controller="ReviewController as reviewCtrl">
<div class="review_form">
<blockquote>
<h3>{{reviewCtrl.review.name}}</h3>
<p>{{reviewCtrl.review.age}}</p>
<p>{{reviewCtrl.review.mail}}</p>
</blockquote>
</div>
<form class="col-md-4 form-group" ng-submit="reviewCtrl.addreview()">
<input type="text" id="name" class="form-control" placeholder="name" ng-model="reviewCtrl.review.name"><br>
<input type="text" id="age" class="form-control" placeholder="age" ng-model="reviewCtrl.review.age"><br>
<input type="mail" id="mail" class="form-control" placeholder="mail" ng-model="reviewCtrl.review.mail"><br>
<input type="submit" class="btn-block btn btn-success" value="Submit Review">
</form>
</div>
</div>
</section>
JavaScript
(function(){
var app=angular.module('store',[]);
app.controller('storeController',function(){
this.product=gem;
});
app.controller('ReviewController',function(){
}
this.review={};
this.addreview=function($scope){
push(this.review);
this.review={};
};
});
var gem=[
{name:'Dodecaheadron',price:2.9,desc:[{comment:'this product is good !'}],avail:true,stock:false},
{name:'Octaheadron',price:2,desc:[{comment:'this product is good !'}],avail:false,stock:true},
{name:'Tetraheadron',price:3.25,desc:[{comment:'this product is good !'}],avail:true,stock:false},
{name:'Pentaheadron',price:4,desc:[{comment:'this product is good !'}],avail:true,stock:false} ];
})();

You have a lot of errors in your JavaScript:
app.controller('ReviewController',function(){
} // Guess you need to change to this });
Solution:
app.controller('ReviewController',function(){
});
Final Script:
(function(){
var app=angular.module('store',[]);
app.controller('storeController',function(){
this.product=gem;
});
app.controller('ReviewController',function(){
});
this.review={};
this.addreview=function($scope){
push(this.review);
this.review={};
};
})();
var gem=[
{name:'Dodecaheadron',price:2.9,desc:[
{comment:'this product is good !'}],avail:true,stock:false},
{name:'Octaheadron',price:2,desc:[
{comment:'this product is good !'}],avail:false,stock:true},
{name:'Tetraheadron',price:3.25,desc:[
{comment:'this product is good !'}],avail:true,stock:false},
{name:'Pentaheadron',price:4,desc:[
{comment:'this product is good !'}],avail:true,stock:false}
];

html dom and javascript

I'm trying to get the elements from textboxes nameBox and foodBox to be displayed in the paragraph id=message after the submit button is clicked, with the message:
“Hello <name in namebox>! We want to let you know that <food in foodbox> has 50% discount in our restaurant!”
But i can't figure out how to do that. I'm pretty sure i'm doing something (if not all) wrong but since i'm new at this i can't figure it out what.
<body>
<br>
<br>
<div>
<p id="message"></p>
</div>
Enter your name:
<input type="text" id="nameBox" value=""><br>
Enter your favorite food
<input type="text" id='foodBox' value=""><br>
<button id="submitButton">Submit</button>
<script>
var parent=document.getElementById("message");
var child=document.getElementById("nameBox");
parent.removeChild(child);
</script>
</body>

That's because parent is not the parent of child. To make it so, edit your code to put the two input elements inside the <p> tag:
<p id="message">
Enter your name:
<input type="text" id="nameBox" value=""><br>
Enter your favorite food
<input type="text" id='foodBox' value=""><br>
</p>

Here you go :
<html>
<head>
<script>
function showText(){
var name=document.getElementById("nameBox").value;
var food=document.getElementById("foodBox").value;
document.getElementById("msg").innerHTML="Hello " + name + " ! We want to let you know that has 50% discount in our restaurant! for " + food;
}
</script>
</head>
<body>
<br>
<br>
<div id="msg">
</div>
Enter your name:
<input type="text" id="nameBox" value=""/><br>
Enter your favorite food
<input type="text" id="foodBox" value=""/><br>
<input type="button" id="submitButton" onclick="showText()" value="Submit" />
</body>
</html>
You can make your alignments as you wish, try to use firebug (https://getfirebug.com/) in case of finding UI related issues. It is pretty easy to figure out what is wrong in the UI

Check your HTML. Maybe it should look like this?
<div id="message">
Enter your name:
<input type="text" id="nameBox" value=""><br>
Enter your favorite food
<input type="text" id='foodBox' value=""><br>
<button id="submitButton">Submit</button>
</div>

You can call function on clicking submit button and then change the message.
<input type="button" id="submit" value="Submit" onclick="somefunction()"/>
Here is the javascript:
function somefunction() {
var fieldNameElement = document.getElementById('message');
fieldNameElement.innerHTML = “Hello ! We want to let you know that has 50% discount in our restaurant!” ;
}
While changing the innerHTML you can add appropriate formatting tags as well.
Also you should add inputs in a table, and add border's and required formatting if required:
<table>
<tr>
<td>
Enter your name:
</td>
<td>
<input type="text" id="nameBox" value=""><br>
</td>
</tr>
<tr>
<td>
Enter your favorite food
</td>
<td>
<input type="text" id='foodBox' value=""><br>
</td>
</tr>
</table>
You can also think about using a Javascript library which provides lot of methods to make your life easy, would suggest JQUERY
Cheers !!