Develop Reference

Insert the attribute value of input element in form

I have a form with no id or class. I need to insert attribute values for input elements.
<form>
<tr><td><input type="text" name="x"/></td></tr>
<tr><td><input type="text" name="y"/></td></tr>
<tr><td><input type="text" name="z"/></td></tr>
</form>
Here's jquery I tried:
var x = $('form').find('input').first().val("some_value");
var y = $('form').find('input').second().val("some_value");
var z = $('form').find('input').third().val("some_value");
// Is there another possible way?
var x = $("form").find('input[name="x"]').val("some_value");

You can use Attribute Equals Selector [name=”value”] to uniquely identify the inputs
$('input[name=x]').val("some_value1");
$('input[name=y]').val("some_value2");
$('input[name=z]').val("some_value3");
Although I wont recommend the method you used to assign values to input, I would suggest you to use find() once and use the returned object collection to assign values. This will reduce the processing time and increase performance.
var all = $('form').find('input');
all.eq(0).val("some_value1");
all.eq(1).val("some_value2");
all.eq(2).val("some_value3");

You can use
$("form").find('input[type="text"]]').each(function() {
$(this).attr("your attribute", "your value");
});

try with this
var x = $('form input[name="x"]').val("some_value_x");

// So you can search across the form for all input elements and then iterate to apply the attribute.
var allInputElements = $("form input[type='text']");
$.each(allInputElements,function(index, item){
$(item).attr("disabled","true");
// You can also use item.prop("any property or attribute","value");
});

If you're giving them all the same value, as it appears in your question, you can simply select them all:
$("form input").val("some_value");

Accessing Input element through input name in javascript

I want to access the following code using java script. Can anyone help me please? I'm a beginner to JavaScript.
<input type="text" name="username" />
I wish to access the element from its name property. An alert box needs to be shown if the length of element value is less than 6.

Use getElementsByName() method,
document.getElementsByName('username')
getElementsByName() returns an array of elements.

The getElementsByName() method returns a collection of all elements in the document with the specified name
var x = document.getElementsByName("username")[0].tagName;
Its better you can use id instead of name if it is unique.
<input type="text" id="username" />
var x=document.getElementById("username");

Try using document.getElementById(), need to specify unique id
var usrtxt = document.getElementById('usrtxt');
alert(usrtxt.name + ": " + usrtxt.value);
<input type="text" name="username" id='usrtxt' value='admin' />
Try using document.getElementsByTagName()
var inputArray = document.getElementsByTagName('input');//gives array
var usrtxt = inputArray[0];//get first element
alert(usrtxt.name + ": " + usrtxt.value);
<input type="text" name="username" value='admin' />

Probably the input is in a form like:
<form ...>
<input name="username">
...
</form>
and probably you want to validate it when the form is submitted, so in that case you likely have a listener on the form like:
<form onsubmit="return validate(this)" ...>
and in the validate function:
function validate(form) {
// get input as form.username
if (form.username.value.length < 6) {
alert('Username must be 6 or more characters long');
// Prevent form submission
return false;
}
}
You may want to be more sophisticated with the UI (your users will appreciate it), but the above shows the basics.

If you wish to identify particular element using Name then use getElementsByName function
Javascript:
var x = document.getElementsByName('username');
If you consider to use the Jquery then please use following code.
Jquery:
$('[name="username"]');
Learn more about Jquery Selectors
Update:
var x = document.getElementsByName('username'); // X is an array here as getElementsByName returns collection i.e. Array
var val = x[0];//get first element
if(val.value.length < 6) // Check if its value greater than 6
{
alert('boom !!');
}
}

How do you return data from javascript into a html form?

I was wondering if anyone can help? What I am trying to do is retrieve the word count from javascript code into a form and then pass it into php along with the rest of the form which will check that the word count is a certain length or else it won't be submitted.
The javascript is as follows.
counter = function() {
var value = $('#msg').val();
if (value.length == 0) {
$('#wordCount').html(0);
$('#totalChars').html(0);
$('#charCount').html(0);
$('#charCountNoSpace').html(0);
return;
}
var regex = /\s+/gi;
var wordCount = value.trim().replace(regex, ' ').split(' ').length;
var totalChars = value.length;
var charCount = value.trim().length;
var charCountNoSpace = value.replace(regex, '').length;
$('#wordCount').html(wordCount);
$('#totalChars').html(totalChars);
$('#charCount').html(charCount);
$('#charCountNoSpace').html(charCountNoSpace);
};
$(document).ready(function() {
$('#count').click(counter);
$('#msg').change(counter);
$('#msg').keydown(counter);
$('#msg').keypress(counter);
$('#msg').keyup(counter);
$('#msg').blur(counter);
$('#msg').focus(counter);
});
My problem is returning wordCount into a hidden field in a form. I am not too good with javascript and am not sure how to modify this code to make it work. The rest I can figure out but am stuck here. Thank you for your help, it is greatly appreciated.

$('#wordCount').val(wordCount);
$('#totalChars').val(totalChars);
$('#charCount').val(charCount);
$('#charCountNoSpace').val(charCountNoSpace);
Use .val() instead of .html(), because .val() refers to the value of an input field.

Your HTML inside the form should include a hidden input field:
<input type="hidden" id="word_count" name="word_count" value="0" />
Then inside your JS:
$('#word_count').val(wordCount);
All together embedded inside your function:
counter = function() {
var value = $('#msg').val();
if (value.length == 0) {
$('#wordCount').html(0);
$('#totalChars').html(0);
$('#charCount').html(0);
$('#charCountNoSpace').html(0);
return;
}
var regex = /\s+/gi;
var wordCount = value.trim().replace(regex, ' ').split(' ').length;
var totalChars = value.length;
var charCount = value.trim().length;
var charCountNoSpace = value.replace(regex, '').length;
$('#wordCount').html(wordCount);
$('#word_count').val(wordCount);
$('#totalChars').html(totalChars);
$('#charCount').html(charCount);
$('#charCountNoSpace').html(charCountNoSpace);
};
$(document).ready(function() {
$('#count').click(counter);
$('#msg').change(counter);
$('#msg').keydown(counter);
$('#msg').keypress(counter);
$('#msg').keyup(counter);
$('#msg').blur(counter);
$('#msg').focus(counter);
});

If you have INPUT fields in your form, use val()
$('#wordCount').val(wordCount)
That would work for a field like this:
Be aware that there's a difference between "id" and "class". jQuery allows you to select elements based on their properties. The "id" property gets selected with "#", just like you'd do it in CSS. So make sure you have that "id='wordCount'" defined in your hidden field.

Have a look at this http://www.hscripts.com/scripts/JavaScript/word-count.php
There are plenty of examples online, just google "javascript count words in textbox"
Some imporntant notes:
A very long string with no spaces is still 1 word so don't forget to set the max length for fields
If you are doing this as a sort of validation be aware of the fact that you can not trust a form field because it can be easily manipulated, so don't forget to check the word count on the server side after the form is submitted.

The Code that you are showing is not just javascript it also includes jquery, please make sure you included jquery
<script src = "http://code.jquery.com/jquery-1.11.1.min.js"></script>
$('#field').val('asdf'); //Sets Value of a input type="text"
$('#field').html('sadf'); //Sets the html of a div
Using javascript you use either value for a input or innerHtml for a div or other text based element
document.getElementById('field').value = 'asdfsadf';
document.getElementById('field').innerHtml= 'asdfsadf';
Also instead of using a form submit consider using jquery $.ajax(there is nothing wrong with form submits but there are benefits to knowing jquery as well such as you came make async requests
http://api.jquery.com/jquery.ajax/
You will want to use a hidden field such as the following and have it in the form
<form id="myform" action='posttome.php'>
<input type="hidden" id="wordCount"/>
<input type="submit" value="sbumit"> //Submits Form
</form>
Then set its value by using of of three methods, a an elements html, an elements value, or a javascript variable $('#wordCount').val()
$('#wordCount').val($('#wordCountSoruceDiv').html()); // Sets the value to another divs html
$('#wordCount').val($('#wordCountSourceInput').val()); // Sets the value to another inputs value
$('#wordCount').val(wordCountVariable); // Sets the value to a variable

How can I create dynamic controls and put their data into an object?

I created a div and a button. when the button clicked, there will be a group of element(included 1 select box and 2 text inputs) inserted into the div. User can add as many group as they can, when they finished type in data of all the group they added, he can hit save button, which will take the value from each group one by one into the JSON object array. But I am stuck in the part how to get the value from each group, so please help, thank you.
The code for the div and the add group button function -- AddExtra() are listed below:
<div id="roomextra">
</div>
function AddExtra() {
$('#roomextra').append('<div class=extra>' +
'<select id="isInset">' +
'<option value="Inset">Inset</option>' +
'<option value="Offset">OffSet</option>' +
'</select>' +
'Length(m): <input type="text" id="insetLength">' +
'Width(m): <input type="text" id="insetWidth">' +
'Height(m): <input type="text" id="insetHeight">' +
'</div>');
}
function GetInsetOffSetArray (callBack) {
var roomIFSDetail = [{
"IsInset": '' ,
"Length": '' ,
"Width": '' ,
"Height": ''
}];
//should get all the value from each group element and write into the array.
callBack(roomIFSDetail);
}

This should just about do it. However, if you're dynamically creating these groups, you'll need to use something other than id. You may want to add a class to them or a data-* attribute. I used a class, in this case. Add those classes to your controls so we know which is which.
var roomIFSDetail = [];
var obj;
// grab all of the divs (groups) and look for my controls in them
$(.extra).each(function(){
// create object out of select and inputs values
// the 'this' in the selector is the context. It basically says to use the object
// from the .each loop to search in.
obj = {
IsInset: $('.isInset', this).find(':selected').val() ,
Length: $('.insetLength', this).val() ,
Width: $('.insetWidth', this).val() ,
Height: $('.insetHeight', this).val()
};
// add object to array of objects
roomIFSDetail.push(obj);
});

you'd better not to use id attribute to identity the select and input, name attribute instead. for example
$('#roomextra').append('<div class=extra>' +
'<select name="isInset">' +
'<option value="Inset">Inset</option>' +
'<option value="Offset">OffSet</option>' +
'</select>' +
'Length(m): <input type="text" name="insetLength">' +
'Width(m): <input type="text" name="insetWidth">' +
'Height(m): <input type="text" name="insetHeight">' +
'</div>');
}
and then, usr foreach to iterate
$(".extra").each(function() {
var $this = $(this);
var isInset = $this.find("select[name='isInset']").val();
var insetLength = $this.find("input[name='insetLength']").val();
// ... and go on
});

A common problem. A couple things:
You can't use IDs in the section you're going to be repeating, because IDs in the DOM are supposed to be unique.
I prefer to use markup where I'm writing a lot of it, and modify it in code rather than generate it there.
http://jsfiddle.net/b9chris/PZ8sf/
HTML:
<div id=form>
... non-repeating elements go here...
<div id=roomextra>
<div class=extra>
<select name=isInset>
<option>Inset</option>
<option>OffSet</option>
</select>
Length(m): <input id=insetLength>
Width(m): <input id=insetWidth>
Height(m): <input id=insetHeight>
</div>
</div>
</div>
JS:
(function() {
// Get the template
var container = $('#roomextra');
var T = $('div.extra', container);
$('#addGroup').click(function() {
container.append(T.clone());
});
$('#submit').click(function() {
var d = {};
// Fill d with data from the rest of the form
d.groups = $.map($('div.extra', container), function(tag) {
var g = {};
$.each(['isInset', 'insetLength', 'insetWidth', 'insetHeight'], function(i, name) {
g[name] = $('[name=' + name + ']', tag).val();
});
return g;
});
// Inspect the data to ensure it's what you wanted
debugger;
});
})();
So the template that keeps repeating is written in plain old HTML rather than a bunch of JS strings appended to each other. Using name attributes instead of ids keeps with the way these elements typically work without violating any DOM constraints.
You might notice I didn't quote my attributes, took the value attributes out of the options, and took the type attributes out of the inputs, to keep the code a bit DRYer. HTML5 specs don't require quoting your attributes, the option tag's value is whatever the text is if you don't specify a value attribute explicitly, and input tags default to type=text if none is specified, all of which adds up to a quicker read and slimmer HTML.

Use $(".extra").each(function() {
//Pull info out of ctrls here
});
That will iterate through all of your extra divs and allow you to add all values to an array.

How do I get a handle to a dynamically-generated field name in javascript?

I have a series of fields created dynamically based on database records. They will be named cardObject1, cardObject2, and so on for as many rows as necessary. I'm now trying to access a specific cardObject field in a function where the number is passed in, but am getting an error message.
The field looks like this:
<input name="cardObject241" value="2,$25.00,1" type="hidden">
The js code I'm using looks like this:
function deleteFromCart(id){
if (confirm("Are you sure you want to delete this item from your cart?")){
var voucherNbr = document.getElementById("voucherNbr").value;
var cardObjectArray = document.getElementById("cardObject"+id).value.split();
var amtToDelete = cardObjectArray[1];
alert("need to delete " + amtToDelete);
}
}
And the error I'm getting is
document.getElementById("cardObject" + id) is null
on this line:
var cardObjectArray = document.getElementById("cardObject"+id).value.split();
How can I get a handle to the cardObject field that ends with the number passed in as the id param?

You need to add an id="" attribute with the same name as the name attribute.
<input id="cardObject241" name="cardObject241" value="2,$25.00,1" type="hidden">

Firstly, your input field needs an id as well as a name, so it would look like this:
<input name="cardObject241" id="cardObject241" value="2,$25.00,1" type="hidden">
Secondly, if you have an object that may or may not exist, it's always a good idea to check for existence before you start manipulating properties:
var tempObj=document.getElementById("cardObject"+id)
if(tempObj) {
var cardObjectArray = tempObj.value.split();
...do your stuff with cardObjectArray....
}

You can use document.getElementsByName() or (cross-browser back to the Stone Age)
document.forms[formIndexOrName].elements["cardObject" + id].value.split(",")