How do I get the value of a textarea? - javascript

This is a follow up to my other question. I am asking again because this seems more a javascript question than a Google App Engine question.
I have a form
<form name="choice_form" id="choice_form" method="post" action="/g/choicehandler" onsubmit="writeToStorage()">
<textarea name="choice" rows="7" cols="50"></textarea><br />
<input type="submit" value="submit your choice">
</form>
I want to take the value of this textarea and send it to the app with formData. I tried this
var choice = document.getElementById("choice_form").value;
but I get "undefined" for the value of "choice". What am I doing wrong?
And also, if I understand correctly, the /g/choicehandler is called twice once by the form and once by the XHR. How do I fix that? Below is the handler:
class Choice(webapp.RequestHandler):
def get(self):
self.response.out.write("""
<html>
<head>
<script type="text/javascript">
var count = 0;
function writeToStorage()
{
var user = "user" + count;
count++;
localStorage.setItem("chooser", user);
var choice = document.getElementById("choice_form").value;
var formData = new FormData();
formData.append("chooser", user);
formData.append("choice", choice);
var xhr = new XMLHttpRequest();
xhr.open("POST", "http://localhost:8086/g/choicehandler", true);
xhr.onreadystatechange = function (aEvt) {
if (xhr.readyState == 4 && xhr.status == 200){
console.log("request 200-OK");
}
else {
console.log("connection error");
}
};
xhr.send(formData);
//added this per Aaron Dufour's answer
return 0;
};
</script>
</head>
<body>
//changed onsubmit like this: onsubmit="return writeToStorage(); as per Aaron Dufour's answer
<form name="choice_form" id="choice_form" action="/g/choicehandler" method="post" onsubmit="writeToStorage()">
<textarea name="choice" rows="7" cols="50"></textarea><br />
<input type="submit" value="submit your choice">
</form>
</body>
</html>""")
UPDATE
See Aaron Dufour's answer for the solution.

choice_form is the <form>, not the <textarea>.
You need to give the <textarea> an ID and use that ID instead.

You can access the form formally using:
document.forms['choice_form']
or also:
document.forms.choice_form
Each form has an elements collection that is all the form controls. You can access them much the same way:
document.forms['choice_form'].elements['choice']
or
document.choice_form.choice
provided the names follow the rules for valid javascript identifiers. If they don't, you need to use square bracket notation:
document['choice_form']['choice']
all return a reference to the element named 'choice' in a form with name 'choice_form'. So to get the value:
document.choice_form.choice.value

(Some great answers here, but I haven’t seen one that puts it together with what you have…)
Since a form can have more than one input, you need to access value on a particular one. There are a few ways to do this, but the most straightforward might be to use the form’s elements property (only forms have this!):
document.getElementById("choice_form").elements.choice.value

As others have said, you're accessing the form, when the data you want is in the textarea. If you give the textarea an ID, that's probably the easiest way to get to its value.
After much discussion, we determined that you don't need XHR at all. Here's what your form should look like:
<form name="choice_form" id="choice_form" action="/g/choicehandler" method="post" onsubmit="writeToStorage()">
<textarea name="choice" rows="7" cols="50"></textarea><br />
<input type="hidden" name="chooser" id="form_chooser" />
<input type="submit" value="submit your choice">
</form>
And now, we use the javascript function to edit the form before allowing it to be submitted:
var count = 0;
function writeToStorage()
{
var user = "user" + count;
count++;
localStorage.setItem("chooser", user);
document.getElementById("form_chooser").value = user;
};

Related

Make an HTML button redirect me to another page [duplicate]

This question already has answers here:
Javascript Button Redirect
(4 answers)
Closed 1 year ago.
How do I make this button redirect me to another page?
<button type="submit" onclick="register()">Create new account</button>
Here is the function that the button is using:
function register() {
let object = {
"username": document.getElementById("username").value,
"password": document.getElementById("password").value
};
let json = JSON.stringify(object);
let xhr = new XMLHttpRequest();
xhr.open("POST", '/api/user/new', false)
xhr.setRequestHeader('Content-type', 'application/json; charset=utf-8');
xhr.send(json);
if (xhr.status != 200) {
alert("Something went wrong!");
} else if (xhr.status == 200){
alert("Success!");
}
}
I want the button to redirect me to 'index.html' file
Try wrapping button in form tag like this:
<form action="index.html">
<button type="submit" onclick="register()">Create new account</button>
</form>
It seems this has already been answered in quite extensive way:
How do I redirect to another webpage?
to sum up: there is a number of ways to achieve that:
// window.location
window.location.replace('http://www.example.com')
window.location.assign('http://www.example.com')
window.location.href = 'http://www.example.com'
document.location.href = '/path'
// jQuery
$(location).attr('href','http://www.example.com')
$(window).attr('location','http://www.example.com')
$(location).prop('href', 'http://www.example.com')
If You want to go there after successful call of the function - put one of these instead of "alert("Success!");"
<form action="/action_page.php" method="get">
<label for="fname">First name:</label>
<input type="text" id="fname" name="fname"><br><br>
<label for="lname">Last name:</label>
<input type="text" id="lname" name="lname"><br><br>
<button type="submit">Submit</button>
<button type="submit" formaction="/action_page2.php">Submit to another page</button>
</form>
Example
A form with two submit buttons. The first submit button submits the form data to "action_page.php", and the second submits to "action_page2.php":
Definition and Usage
The formaction attribute specifies where to send the form-data when a form is submitted. This attribute overrides the form's action attribute.
The formaction attribute is only used for buttons with type="submit".
Please refer this link: https://www.w3schools.com/tags/att_button_formaction.asp

How can i validate form with JavaScript

I want to create a form and want to validate user input, if user fill both text box i want to show an alert box, also if user fill one and left empty another one i want to show an alert box to let them know that they are missing one box. How i can do it with JavaScript, please help.
I want two text box, if user fill both text box and click enter i want to show an alert box telling them "Correct", if user fill one and left another empty i want to show an alert box telling them that it is "Incorrect".
How i can do it, help.
<form action="" method="post">
<input type="text" name="text1" placeholder="Text 1">
</br>
<input type="text" name="text2" placeholder="Text 2">
</br>
<input type="submit" value="Enter">
</form>
What kind of validation are you interested in ?
You can do everything with javascript my friend:).
This is pure javascript. To make it simple, I kept the html and js in one file. I also added a name to a form as you see below, in case you would have multiple forms.
<html>
<body>
<form name="LovelyForm" action="" method="post">
<input type="text" name="text1" placeholder="Text 1"> </br>
<input type="text" name="text2" placeholder="Text 2"> </br>
<input type="submit" onclick="validateForm()" value="Enter">
</form>
<script type="text/javascript">
function validateForm() {
var x = document.forms["LovelyForm"]["text1"].value;
var y = document.forms["LovelyForm"]["text2"].value;
if (x == null || x == "" || y == null || y == "") {
alert("Fill me in");
return false;
}else{
alert("Good");
return true;
}
}
</script>
</body>
</html>
Validation with javascript is the most flexible way and works with all browsers, if you learn JQuery you will be able to improve the user experience limit less.
If you don't want to javascript then use the new improved input validation options with Html 5, they will work with most browsers and not break the ones without Html5 support.
Here: Best practice as I see it :)
Only validate the most necessary on client side.
Avoid compulsory input unless they realy are.
Don't refuse space, hyphens, commas, dots and so on if you absolutely don't have to. People like to cut and paste. You can always clean on server side.
Don't limit input length/size if you don't have to. Again people like to cut and paste and many times the input is to long just because it contains blank spaces.
Most important of all. You must always validate on server side, to make sure your data won't get corrupted. Client validation is only to improve the users experience and not a substitute.
Here's a JSFiddle that should work with IE < 9: http://jsfiddle.net/ayr7yov7/1/
form.elements['one'].value may cause issues if the inputs are not of type text.
The code:
<script>
function trim(str) {
if(!str) return '';
return str.replace(/\s{2,}/g, '');
}
function valid(form) {
var v1 = trim(form.elements['one'].value),
v2 = trim(form.elements['two'].value);
if (v1 === '') {
alert('one');
return false;
}
if (v2 === '') {
alert('two');
return false;
}
alert('full!')
return true;
}
</script>
<form action="/echo/json/" onsubmit="return valid(this)">
<input name="one" type="text" />
<input name="two" type="text" />
<input type="submit" />
</form>
First step is to give JavaScript an easy way to reference the element in the DOM. Generally, the easiest way is to give each element you need to reference a unique ID.
<input id="num1" />
<input id="num2" />
Then, JavaScript can access the inputs with the getElementById() method of the document object (the "D" from DOM).
var i1 = document.getElementById("num1");
var i2 = document.getElementById("num1");
Now, i1 and i2 contain a reference to their respective input objects (the "O" from DOM). Every form element object has a value attribute that contains the current value of it's input.
var val1 = i1.value;
var val2 = i2.value;
Now var1 and var2 contain the value of the input. All you have to do is check and see if they both have a value that isn't empty.
if(
// if the first value does not equal an empty string ""..
val1 != ""
// and the second value does not equal an empty string ""..
&& val1 != ""
)
// then alert 'correct'
alert("correct");
// or else, alert 'incorrect'
else alert('incorrect');
Now you can throw it in a function and make it run when the form is submitted by attaching it to an event handler. When you're just starting it's easiest to use an onsubmit attribute, which takes the name of a function and calls that function when the form is submitted.
<form action="#" onsubmit="validate()">
<input id="num1" />
<input id="num2" />
<input type="submit" />
</form>
<script>
function validate(){
var i1 = document.getElementById("num1");
var i2 = document.getElementById("num1");
var val1 = i1.value;
var val2 = i2.value;
if(val1 != "" && val2 != "") alert("correct");
else alert("incorrect");
}
</script>

AJAX Form, passing return message

I have my AJAX form it works great.
Every time I submit the form It returns the result inside the <div id="message"></div>, but it gets complicated when I have multiple forms. So I was wondering if their is a way to indicate inside the form what <div> to return the message to.
Here is my AJAX.js
$("form#ajaxForm").on("submit", function() {
var form = $(this),
url = form.attr("action"),
type = form.attr("method");
data = {};
form.find("[name]").each(function(index, value){
var input = $(this),
name = input.attr("name"),
value = input.val();
data[name] = value;
});
$.ajax({
url: url,
type: type,
data: data,
success: function(response) {
$("#message").html(response); //I would like to interactively switch the return div, from #message to like #message2
$("body, html").animate({
scrollTop: $( $("#message") ).offset().top - 5000
}, 600);
}
});
return false;
});
In the form I would like to indicate where the return div is, like
<form action="../forms/add_event_form.php" method="post" id="ajaxForm">
//Can I add an input somewhere here? To indicate where I want the return to go too? Like <input type="hidden" value="message2" name="return">
<input type="text" class="formI" name="date" id="dateI" placeholder="Date">
<input type="submit" name="submit" class="btn btn-primary" value="Add">
</form>
Thank you for reading this. Have a good day! And Thank you in advance for your responses.
Yes, it will not work automatically, but you can add some information to the form and then use it to decide where to put returned HTML. Doing that with additional inputs may not be the best way though, as it can be achieved with far less impact on the DOM: with an attribute on the form itself.
Here's an example of how you may do that.
$(".ajaxForm").on("submit", function(e) {
e.preventDefault();
var form = $(this);
// using jQuery's `data()` to get an ID of response element from the 'data-response' attribute
var responseElementId = form.data("response");
var response = $(responseElementId);
response.html(produceResponse(form));
// function that produces some html response
// you'll use AJAX request to the server for that
// so don't mind its complexity or bugs
function produceResponse(form) {
var data = form.find("input").map(function(i, el) {
return "'" + el.name + "': " + el.value;
});
return "<p>You've submitted:\n<pre>" + Array.prototype.join.call(data, ",\n") + "</pre></p>";
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h2>Form #1</h2>
<form action="#" class="ajaxForm" data-response="#response1">
<input name="first-name" type="text">
<button>Submit</button>
</form>
<div id="response1"></div>
<h2>Form #2</h2>
<form action="#" class="ajaxForm" data-response="#response2">
<input name="last-name" type="text">
<button>Submit</button>
</form>
<div id="response2"></div>
Here I use a data attribute because it was designed for cases like this: to store arbitrary data related to the element, but which doesn't have any defined meaning for the browser. Accessing data stored in such way is really convenient with its HTML5 API, but because of pretty low support from IE (it has it only starting from the version 11), one may use jQuery's method data() to do the same.

How to get formData from Angular-Payments

I am using Angular-Payments that intercepts the form data and submits it to Stripe. This works well, however, I'm not sure how to access form data after its sent to stripe. For example, my form has quantity field which I would like to get access to but I don't know how to...
Here is what I'm doing HTML
<form stripe-form="handleStripe" role="form" ng-if="authenticated" name="takeMoneyForm" ng-submit="takeMoney(takeMoneyForm, model)">
<input type="text" name="card_number" ng-model="number" payments-validate="card" payments-format="card" payments-type-model="type" ng-class="takeMoneyForm.number.$card.type">
<input type="text" name="card_cvc" ng-model="cvc" payments-validate="cvc" payments-format="cvc" payments-type-model="type">
<input type="text" nam="card_expiry" ng-model="expiry" payments-validate="expiry" payments-format="expiry">
<input type="text" ng-model="quantity"/>
<button class='form-control submit-button btn btn-majoo' type='submit'>Pay »</button>
</form>
JS
$scope.takeMoney = function(formData, model){
$scope.handleStripe = function(status, response){
if(response.error) {
// there was an error. Fix it.
alert("Error happened")
} else {
var dataModel = {
email: model.email,
profile: {
stripe_token: response.id,
stripe_id: model.profile.stripe_id
//here I would like to get access to the quantity from the form
}
}
djangoAuth.takeMoney(dataModel)
$scope.complete = true;
}
}
}
I feel like this should be simple but I'm very new to Angular and can't seem to figure this out.
since youre using ng-model the values of those fields should be on that form's scope(as in scope.number)
If they are not accessible it could be one of two things:
1) Angular Payments clears the ng-model following submit
2) you are trying to access it from a different scope.

Pass variable to HTML form Javascript

Please excuse my inexperience as I am not a programmer just someone who dabbles at trying to make something work. I'm not sure of the correct terminology and complicated explanations will go straight over my head!
In essence I am trying to get part of the URL of a web page passed to a simple Form that is linked to a shopping cart. i.e. how do I get the filename into the form where I have xxxxxxx. Is it possible in Javascript?
<script type="text/javascript">
var url = window.location.pathname;
var filename = url.substring(url.lastIndexOf('/')+1);
document.write (filename);
</script>
<form action="http://www.mywebspace.com/cf/add.cfm" method="post">
<input type="hidden" name="userid" value="12345678">
<input type="hidden" name="product" value="xxxxxxx">
<input type="hidden" name="price" value="5.00">
<input type="Submit" value="Buy now!">
</form>
I've provided a snippet code that will work with your current HTML structure. Though I do suggest you give the product field an id to prevent the necessity to loop and search elements:
var url = window.location.pathname,
filename = url.substring(url.lastIndexOf('/')+1);
fields = document.getElementsByTagName('input');
for(var i = 0; i < fields.length; i++){
if(fields[i].name == 'product') {
fields[i].value = filename;
break;
}
}
If the form only exists once on a given page, this is an easy solution:
Change it to be:
<input type="hidden" id="productField" name="product" value="xxxxxxx">
In your javascript,
document.getElementById('productField').value = filename;
Yes this is possible.
Instead of doing document.write you need to update the form. Assuming your filename value is currently correct:
//js
document.getElementById( "name-of-file").value = filename;
<!- html -->
...
...

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