How do I use DOM element's attribute value as a variable? - javascript

Got a number of dynamic values assigned to variables from outside the form. And I need to pass them to form. Now, I could do each field individually like this.
this would be the form
<form>
<input type="text" class="inputfield widthfield" id="widthval" />
<input type="text" class="inputfield fontsizefield" id="fontsize" />
</form>
And this would be jquery
widthval = '300px'
fontsize = '15px'
$(".widthfield").val(widthval);
$(".fontsizefield").val(fontsize);
and so on. But there is a ton of these fields, and this doesn't look right. So, I was wondering if there is any way to use field id to match field and variable.
Something like this perhaps (the logic).
$(".inputfield").each(function(){
matchattr = $(this).attr("id");
$(this).val(matchattr);
});
In this case, it uses the actual value of an attribute. How do I turn that value into variable that has the dynamic value assigned to it?
Thanks!

Given that your variables match the ids of the inputs, you could put your values in an object, loop over the keys, and set them when they match.
var data = {
widthval: '300px',
fontsize: '15px'
};
var $inputfields = $('.inputfield');
Object.keys(data).forEach(function(key){
$inputfields.filter('#'+ key).val(data[key]);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
<input type="text" class="inputfield widthfield" id="widthval" />
<input type="text" class="inputfield fontsizefield" id="fontsize" />
</form>

Related

Get the id of input using it's name

I want to get the id of input using it's name,and to empty the input field.But it's not working.Is it possible?
html:
<input type="text" id="1" name="Color" maxlength="2" />
jQuery:
var myId="#";
myId=myId + $('[name="Color"]').attr('id');
$($myId).var('');
You can do this:
let id = $('input[name$="Color"]').val('').attr('id');
console.log(id);
$(`#${id}`).val('');
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="1" name="Color" maxlength="2" />
You can set the input value using the val() function.
<input type="text" id="1" name="Color" maxlength="2"/>
var myId='#' + $('[name="Color"]').attr('id');
$(myId).val('');
To get the input value use it like this:
$(myId).val();
Try this code.
const myId = $('input[name="Color"]').attr('id');
$("#"+myId).val(''); // you can set any value here or you can perform any other operations on this element -> $("#"+myId)
On first line of this JS code, we are getting id attribute and then on second line, we're using to manipulate element.
Now, if you want id only for performing some operations on that input element, you don't need to get id. You can also do like this.
let elem = $('input[name="Color"]');
elem.val(''); // only if same name is not used anywhere else.
I hope this helps you.
You can use attr directly to set a value. Moreover there is no need to append #.
let element = $('[name="Color"]');
console.log("before", element.attr('id'));
element.attr('id', null);
console.log("after", element.attr('id'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="1" name="Color" maxlength="2" />

How do I change the value of input elements with a date ? val()/attr()/change() not working

I have a date selection element
#Html.RadioButton("radioTimeFilter", "range", false) Date Range
<span id="dateRangeControls" style="display:none;">
<input id="txtDateOneFilter" type="text" style="width: 70px;" value="test" #*placeholder="Start Date"*# /> to
<input id="txtDateTwoFilter" type="text" style="width: 70px;" value="test" #*placeholder="End Date"*# />
</span>
and on document ready i'm trying to set these values being passed from another page
$(document).ready(function () {
$("#timeFilter").val("#ViewBag.timeFilter").change();
console.log("#ViewBag.dateStart");
console.log("#ViewBag.dateEnd");
// below fails
$("#txtDateOneFilter").attr("value", '#ViewBag.dateStart');
$("#txtDateTwoFilter").attr("value", '#ViewBag.dateEnd');
//
$("#ddlDistrictFilter").val("#ViewBag.districtId").change();
});
i've tried .val() and using .change() and a bunch of other things. Nothing seems to work. How can I change these values after the page loads
Check out this example:
https://stackblitz.com/edit/js-ptckvo
Copy the code and modify the dateOne and dateTwo values with the ViewBag (keep the quote marks inside the val):
$(document).ready(function() {
$("#txtDateOneFilter").val('#ViewBag.dateStart');
$("#txtDateTwoFilter").val('#ViewBag.dateEnd');
});
If it doesn't work, maybe the problem is in the ViewBag values.

select particular input field name of particular form

i have some html code like this
<form name="first"><input name="firstText" type="text" value="General" />
<input name="secondText" type="text" value="General" />
<input name="ThirdText" type="text" value="General" />
<input name="FourthText" type="text" value="General" />
<input name="FifthText" type="text" value="General" />
</form>
<form name="second"><input name="firstText" type="text" value="General" />
<input name="secondText" type="text" value="General" />
<input name="ThirdText" type="text" value="General" />
<input name="FourthText" type="text" value="General" />
<input name="FifthText" type="text" value="General" />
</form>
i want to select "secondText" of form "second" using jquery or javascript and i want to change value of it using jquery.
Using jQuery:
var element = $("form[name='second'] input[name='secondText']");
Using vanilla JS:
var element = document.querySelector("form[name='second'] input[name='secondText']");
Changing the value: element.val(value) or element.value = value, depending of what you are using.
To the point with pure JS:
document.querySelector('form[name=particular-form] input[name=particular-input]')
Update:
This selector will return the input named "particular-input" inside form named "particular-form" if exists, otherwise returns null.
The selector filter "form[name=particular-form]" will look for all forms with name equals "particular-form":
<form name="particular-form">
The selector filter "input[name=particular-input]" will look for all input elements with name equals "particular-input":
<input name="particular-input">
Combining both filters with a white space, I mean:
"form[name=particular-name] input[name=particular-input]"
We are asking for querySelector(): Hey, find all inputs with name equals "particular-input" nested in all forms with name equals "particular-form".
Consider:
<form name="particular-form">
<input name="generic-input">
<input name="particular-input">
</form>
<form name="another-form">
<input name="particular-input">
</form>
<script>
document.querySelector('form[name=particular-form] input[name=particular-input]').style.background = "#f00"
</script>
This code will change the background color only of the second input, no matter the third input have same name. It is because we are selecting only inputs named "particular-input" nested in form named "particular form"
I hope it's more clear now.
;)
By the way, unfortunately I didn't found good/simple documentation about querySelector filters, if you know any reference, please post here.
// Define the target element
elem = jQuery( 'form[name="second"] input[name="secondText"]' );
// Set the new value
elem.val( 'test' );
Try
$("form[name='second'] input[name='secondText']").val("ENTER-YOUR-VALUE");
You can do it like this:
jQuery
$("form[name='second'] input[name='secondText']").val("yourNewValue");
Demo: http://jsfiddle.net/YLgcC/
Or:
Native Javascript
Old browsers:
var myInput = [];
myInput = document.getElementsByTagName("input");
for (var i = 0; i < myInput.length; i++) {
if (myInput[i].parentNode.name === "second" &&
myInput[i].name === "secondText") {
myInput[i].value = "yourNewValue";
}
}
Demo: http://jsfiddle.net/YLgcC/1/
New browsers:
document.querySelector("form[name='second'] input[name='secondText']").value = "yourNewValue";
Demo: http://jsfiddle.net/YLgcC/2/
You can try this line too:
$('input[name="elements[174ec04d-a9e1-406a-8b17-36fadf79afdf][0][value]"').mask("999.999.999-99",{placeholder:" "});
Add button in both forms. On Button click find nearest form using closest() function of jquery. then using find()(jquery function) get all input values. closest() goes in upward direction in dom tree for search and find() goes in downward direction in dom tree for search. Read here
Another way is to use sibling() (jquery function). On button click get sibling input field values.

Enable checkbox if text field is not empty with inconsistent id

Purpose is to have checkboxes disabled when the page loads, and remain greyed out until textbox is filled.
<input type="text" name="<%=commentID%>" />
<input type="checkbox" name="<%=SkipID%>" value="N" disabled/>
I tried to do something like
<input type="text" name="<%=commentID%>" onkeyup="userTyped('<%=SkipID%>') />
function userTyped(commen){
if(this.value.length > 0){
document.getElementById(commen).disabled=false;
}else{
document.getElementById(commen).disabled=true;
}
}
But it did not work. I am assuming because of the inconsistency of the name, but I have to have that.
You haven't given id to your html elements and is trying to use getElementById, which will return null. Javascript engine will not be able to set disabled attribute of null. Try setting id attribute, for elements as given below.
Also in your userTyped function you are referencing this. this here is the window object and not the input element. You need to pass the reference to input element to make this work, like this onkeyup="userTyped('<%=SkipID%>', this)"
Please find a possible correction below:
<input type="text" name="<%=commentID%>" id="<%=commentID%>" onkeyup="userTyped('<%=SkipID%>', this)" />
<input type="checkbox" name="<%=SkipID%>" id="<%=SkipID%>" value="N" disabled/>
/** commen is the id
* e is the input element
**/
function userTyped(commen, e){
if(e.value.length > 0){
document.getElementById(commen).disabled=false;
}else{
document.getElementById(commen).disabled=true;
}
}
jsFiddle here: http://jsfiddle.net/deepumohanp/dGS9H/

retrieving text field value using javascript

I want to retrieve textfield value using javascript. suppose i have a code like:
<input type='text' name='txt'>
And I want to retrieve it using javascript. I call a function when a button is clicked:
<input type='button' onclick='retrieve(txt)'>
What coding will the retrieve function consist of?
You can do this:
Markup:
<input type="text" name="txt" id="txt"/>
<input type="button" onclick="retrieve('txt');"/>
JavaScript:
function retrieve(id) {
var txtbox = document.getElementById(id);
var value = txtbox.value;
}
Let's say you have an input on your page with an id of input1, like this:
<input type="text" id="input1" />
You first need to get the element, and if you know the Id, you can use document.getElementById('input1'). Then, just call .value to get the value of the input box:
var value = document.getElementById('input1').value;
Update
Based on your markup, I would suggest specifying an id for your text box. Incase you don't have control over the markup, you can use document.getElementsByName, like so:
var value = document.getElementsByName('txt')[0].value;
One of the way is already explained by Andrew Hare.
You can also do it by entering the value in the textbox and getting a prompt box with entered message when a user click the button.
Let's say, you have a textbox and a input button
<input type="text" name="myText" size="20" />
<input type="button" value="Alert Text" onclick="retrieve()" />
The function for retrieve()
function retrieve()
{
var text = document.simpleForm.myText.value;
alert(text);
}

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