How to Refer back to Its Label from Input Field? - html

Using for we can link a label with a control say <input>, so clicks on the label sets focus into the control. Great.
This maybe a silly question. What about the other way? I want to be able to tell which label this input is associated with. For example
<form [formGroup]="MyForm">
<label id="RemoteLabel" for="FarAwayControl">Far Away</label>
...
<input id="FarAwayControl" formControlName="FarAwayControl">
So far don't see any direct property of this.MyForm.controls.FarAwayControl link back to label, maybe only option is to traverse back to parent...

It appears that <input /> elements have a labels property that returns a NodeList of associated <label> elements. From the MDN page:
The HTMLInputElement.labels read-only property returns a NodeList of the <label> elements associated with the <input> element, if the element is not hidden. If the element has the type hidden, the property returns null.
You can see it here in action:
const myInput = document.querySelector('#username');
const myInputLabel = myInput.labels[0];
console.log(`My input is labelled as "${myInputLabel.textContent}".`);
<label for="username">Click me</label>
<input type="text" id="username">
Please note that this feature is not supported in Internet Explorer (if that matters to you).

Related

Can I put checkbox and hidden input inside a label?

I have a list of possible products a user can buy. For doing it, I use ul tag combined with li.
Every element has a checkbox that allows the user to choose if select the product or not.
Some products have related information. In order to describe this, I would like to store the data inside an hidden input. But because the selection and the information are related to a product I thought to use a label that contains the checkbox and the hidden input.
Something like
<label class="product">
<input class="product-checkbox" name="product1" type="checkbox">
<input type="hidden" name="product1-information" value="{...}" />
<span class="product-name">Product1</span>
</label>
If I understood correctly, a label cannot refer to an hidden input but in the above example, accordingly to the w3c, the labeled control is the checkbox.
Anyway I'm wandering if a label can contains checkbox and an hidden input.
So, is the above snipper correct?
You're right on both counts. From MDN
The form control that a label is labeling is called the labeled control of the label element. Multiple labels can be associated with the same form control:
<label for="username">Enter your username:</label>
<input id="username">
<label for="username">Forgot your username?</label>
Elements that can be associated with a <label> element include <button>, <input> (except for type="hidden"), <meter>, <output>, <progress>, <select> and <textarea>.
(emphasis mine)
That makes it pretty clear to me that (a) multiple things inside a <label> block is entirely acceptable, and (b) hidden inputs will not be considered targets of the label.

Label for input inside other label - is this correct

This is best illustrated with an example:
<label for="myInput">This is an external label</label>
<br>
<label>
This label is wrapped arround the input
<input type="text" id="myInput">
</label>
Is this correct in HTML5? I understand multiple labels can point at one input field, but a label can only point at one field. In the example it are two labels pointing at the same input, only one is wrapping around the input.
Is this correct in HTML5?
Yes.
I understand multiple labels can point at one input field, but a label
can only point at one field
Yes, again.
From the specs here: https://www.w3.org/TR/html5/forms.html#the-label-element
The caption can be associated with a specific form control, known as
the label element's labeled control, either using the for attribute,
or by putting the form control inside the label element itself.
When there is no for attribute and the label is nested with its labelable control, then the first such descendant becomes its labelable control. But, a label should not be nested with other labels.
The label.control property returns the form control that is associated with this element. Vice-versa, .labels is a readonly property on labelable controls which return a nodelist of all applicable labels on that control.
Example 1:
In the example below, the input.labels property returns a nodeList which contains both the labels.
var inp = document.getElementById('myInput');
console.log(inp.labels);
<label for="myInput">This is an external label</label>
<br>
<label>
This label is wrapped around
<input type="text" id="myInput">
</label>
Example 2:
In this example, I have purposefully associated one label to two inputs. See that only the first one encountered i.e. with the for attribute here gets associated, and the second one is ignored even though it has a nested control.
var myInput = document.getElementById('myInput'),
yourInput = document.getElementById('yourInput')
;
console.log(myInput.labels);
console.log(yourInput.labels);
<label for="myInput">
This is an external label
<input id="yourInput">
</label>
<br>
<input type="text" id="myInput">

What is the HTML for="" attribute in <label>?

I have seen this in jQuery - what does it do?
<label for="name"> text </label>
<input type="text" name="name" value=""/>
The for attribute is used in labels. It refers to the id of the element this label is associated with.
For example:
<label for="username">Username</label>
<input type="text" id="username" name="username" />
Now when the user clicks with the mouse on the username text the browser will automatically put the focus in the corresponding input field. This also works with other input elements such as <textbox> and <select>.
Quote from the specification:
This attribute explicitly associates the label being defined with
another control. When present, the value of this attribute must be the
same as the value of the id attribute of some other control in the
same document. When absent, the label being defined is associated with
the element's contents.
As far as why your question is tagged with jQuery and where did you see it being used in jQuery I cannot answer because you didn't provide much information.
Maybe it was used in a jQuery selector to find the corresponding input element given a label instance:
var label = $('label');
label.each(function() {
// get the corresponding input element of the label:
var input = $('#' + $(this).attr('for'));
});
To associate the <label> with an <input> element, you need to give the <input> an id attribute. The <label> then needs a for attribute whose value is the same as the input's id:
<label for="username">Click me</label>
<input type="text" id="username">
The for attribute associates a <label> with an <input> element; which offers some major advantages:
1. The label text is not only visually associated with its corresponding text input; it is programmatically associated with it too. This means that, for example, a screen reader will read out the label when the user is focused on the form input, making it easier for an assistive technology user to understand what data should be entered.
2. You can click the associated label to focus/activate the input, as well as the input itself. This increased hit area provides an advantage to anyone trying to activate the input, including those using a touch-screen device.
Alternatively, you can nest the <input> directly inside the <label>, in which case the for and id attributes are not needed because the association is implicit:
<label>Click me <input type="text"></label>
Notes:
One input can be associated with multiple labels.
When a <label> is clicked or tapped and it is associated with a form control, the resulting click event is also raised for the associated control.
Accessibility concerns
Don't place interactive elements such as anchors or buttons inside a label. Doing so, makes it difficult for people to activate the form input associated with the label.
Headings
Placing heading elements within a <label> interferes with many kinds of assistive technology, because headings are commonly used as a navigation aid. If the label's text needs to be adjusted visually, use CSS classes applied to the <label> element instead.
If a form, or a section of a form needs a title, use the <legend> element placed within a <fieldset>.
Buttons
An <input> element with a type="button" declaration and a valid value attribute does not need a label associated with it. Doing so may actually interfere with how assistive technology parses the button input. The same applies for the <button> element.
Ref:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/label
I feel the need to answer this. I had the same confusion.
<p>Click on one of the text labels to toggle the related control:</p>
<form action="/action_page.php">
<label for="female">Male</label>
<input type="radio" name="gender" id="male" value="male"><br>
<label for="female">Female</label>
<input type="radio" name="gender" id="female" value="female"><br>
<label for="other">Other</label>
<input type="radio" name="gender" id="other" value="other"><br><br>
<input type="submit" value="Submit">
</form>
I changed the for attribute on the 'male' label to female. Now, if you click 'male' the 'female' radio will get checked.
Simple as that.
a fast example:
<label for="name">Name:</label>
<input id="name" type="text" />
the for="" tag let focus the input when you click the label as well.
You use it with labels to say that two objects belong together.
<input type="checkbox" name="remember" id="rememberbox"/>
<label for="rememberbox">Remember your details?</label>
This also means that clicking on that label will change the value of the checkbox.
FYI - if you are in an typescript environment with e.g.
<label for={this.props.inputId}>{this.props.label}</label>
you need to use htmlFor
<label htmlFor={this.props.inputId}>{this.props.label}</label>
it is used for <label> element
it is used with input type checkbox or redio to select on label click
working demo
The for attribute of the <label> tag should be equal to the id attribute of the related element to bind them together.
It associates the label with an input element. HTML tags are meant to convey special meaning to users of various categories. Here is what label is meant for:
For people with motor disabilities (also for general mouse users): Correctly used label tags can be clicked to access the associated form control. Eg. Instead of particularly clicking the checkbox, user can click on more easily clickable label and toggle the checkbox.
For visually-challenged users: Visually challenged users use screen-readers that reads the associated label tag whenever a form control is focused. It helps users to know the label which was otherwise invisible to them.
More about labelling -> https://www.w3.org/TR/WCAG20-TECHS/H44.html
it is used in <label> text for html
eg.
<label for="male">Male</label>
<input type="radio" name="sex" id="male" value="male"><br>
It's the attribute for <label> tag : http://www.w3schools.com/tags/tag_label.asp

HTML input field OUTSIDE of a form

I have a form with a set of inputs, and I want my page to refresh when one of them changes. I have a second set of inputs on the OTHER side of the page, and the css layout doesn't make it convenient for me to put them in the same <form> </form> tag. I was wondering if there is a way that I can make sure those "inputs" that are located outside of the <form> tag are still associated with that form.
Is there some way we can assign a "form id" to the inputs?
In HTML5, you can use the form attribute:
A form-associated element is, by default, associated with its ancestor form element, but may have a form attribute specified to override this.
If a form-associated element has a form attribute specified, then that attribute's value must be the ID of a form element in the element's owner Document.
Example:
<form id="myform">
<input id="something" type="text">
</form>
<button form="myform" type="submit">Submit that form over there</button>
You should however make sure that it is clear to the user that these visually separated form elements are in fact connected.
<input type="text" form="myform" /> worked for me.
Update
This worked great with FireFox, however gave me trouble in IE 11 as the form attribute is not recognized with IE (as of writing this).
I had to just set a hidden input field inside the form, and transferred value to hidden input field from input outside form; with onclick using jQuery.
<input class="checkbox" id="staff_recruiting" name="company_type"
value="staff_recruiting" type="checkbox">
<input type="hidden" value="all" name="keyword" id="search-keyword-input">
$('#search-keyword').keyup(function() {
$('#search-keyword-input').val($(this).val());
});
Your problem will be solved bro:
Add a hidden input field in your form.
Using jQuery or JS to change that hidden input field value with that outside input box.
Your page will refresh and your outside box value will be grabbed.

Should I put input elements inside a label element?

Is there a best practice concerning the nesting of label and input HTML elements?
classic way:
<label for="myinput">My Text</label>
<input type="text" id="myinput" />
or
<label for="myinput">My Text
<input type="text" id="myinput" />
</label>
From the W3's HTML4 specification:
The label itself may be positioned before, after or around the
associated control.
<label for="lastname">Last Name</label>
<input type="text" id="lastname" />
or
<input type="text" id="lastname" />
<label for="lastname">Last Name</label>
or
<label>
<input type="text" name="lastname" />
Last Name
</label>
Note that the third technique cannot be used when a table is being used for layout, with the label in one cell and its associated form field in another cell.
Either one is valid. I like to use either the first or second example, as it gives you more style control.
I prefer
<label>
Firstname
<input name="firstname" />
</label>
<label>
Lastname
<input name="lastname" />
</label>
over
<label for="firstname">Firstname</label>
<input name="firstname" id="firstname" />
<label for="lastname">Lastname</label>
<input name="lastname" id="lastname" />
Mainly because it makes the HTML more readable. And I actually think my first example is easier to style with CSS, as CSS works very well with nested elements.
But it's a matter of taste I suppose.
If you need more styling options, add a span tag.
<label>
<span>Firstname</span>
<input name="firstname" />
</label>
<label>
<span>Lastname</span>
<input name="lastname" />
</label>
Code still looks better in my opinion.
Behavior difference: clicking in the space between label and input
If you click on the space between the label and the input it activates the input only if the label contains the input.
This makes sense since in this case the space is just another character of the label.
div {
border: 1px solid black;
}
label {
border: 1px solid black;
padding: 5px;
}
input {
margin-right: 30px;
}
<p>Inside:</p>
<label>
<input type="checkbox" />
Label. Click between me and the checkbox.
</label>
<p>Outside:</p>
<input type="checkbox" id="check" />
<label for="check">Label. Click between me and the checkbox.</label>
Being able to click between label and box means that it is:
easier to click
less clear where things start and end
Bootstrap checkbox v3.3 examples use the input inside: http://getbootstrap.com/css/#forms Might be wise to follow them. But they changed their minds in v4.0 https://getbootstrap.com/docs/4.0/components/forms/#checkboxes-and-radios so I don't know what is wise anymore:
Checkboxes and radios use are built to support HTML-based form validation and provide concise, accessible labels. As such, our <input>s and <label>s are sibling elements as opposed to an <input> within a <label>. This is slightly more verbose as you must specify id and for attributes to relate the <input> and <label>.
UX question that discusses this point in detail: https://ux.stackexchange.com/questions/23552/should-the-space-between-the-checkbox-and-label-be-clickable
If you include the input tag in the label tag, you don't need to use the 'for' attribute.
That said, I don't like to include the input tag in my labels because I think they're separate, not containing, entities.
Personally I like to keep the label outside, like in your second example. That's why the FOR attribute is there. The reason being I'll often apply styles to the label, like a width, to get the form to look nice (shorthand below):
<style>
label {
width: 120px;
margin-right: 10px;
}
</style>
<label for="myinput">My Text</label>
<input type="text" id="myinput" /><br />
<label for="myinput2">My Text2</label>
<input type="text" id="myinput2" />
Makes it so I can avoid tables and all that junk in my forms.
See http://www.w3.org/TR/html401/interact/forms.html#h-17.9 for the W3 recommendations.
They say it can be done either way. They describe the two methods as explicit (using "for" with the element's id) and implicit (embedding the element in the label):
Explicit:
The for attribute associates a label with another control explicitly: the value of the for attribute must be the same as the value of the id attribute of the associated control element.
Implicit:
To associate a label with another control implicitly, the control element must be within the contents of the LABEL element. In this case, the LABEL may only contain one control element.
Both are correct, but putting the input inside the label makes it much less flexible when styling with CSS.
First, a <label> is restricted in which elements it can contain. For example, you can only put a <div> between the <input> and the label text, if the <input> is not inside the <label>.
Second, while there are workarounds to make styling easier like wrapping the inner label text with a span, some styles will be in inherited from parent elements, which can make styling more complicated.
3rd party edit
According to my understanding html 5.2 spec for label states that the labels Content model is Phrasing content. This means only tags whose content model is phrasing content <label> are allowed inside </label>.
Content model A normative description of what content must be included
as children and descendants of the element.
Most elements that are categorized as phrasing content can only
contain elements that are themselves categorized as phrasing content,
not any flow content.
A notable 'gotcha' dictates that you should never include more than one input element inside of a <label> element with an explicit "for" attribute, e.g:
<label for="child-input-1">
<input type="radio" id="child-input-1"/>
<span> Associate the following text with the selected radio button: </span>
<input type="text" id="child-input-2"/>
</label>
While this may be tempting for form features in which a custom text value is secondary to a radio button or checkbox, the click-focus functionality of the label element will immediately throw focus to the element whose id is explicitly defined in its 'for' attribute, making it nearly impossible for the user to click into the contained text field to enter a value.
Personally, I try to avoid label elements with input children. It seems semantically improper for a label element to encompass more than the label itself. If you're nesting inputs in labels in order to achieve a certain aesthetic, you should be using CSS instead.
As most people have said, both ways work indeed, but I think only the first one should. Being semantically strict, the label does not "contain" the input. In my opinion, containment (parent/child) relationship in the markup structure should reflect containment in the visual output. i.e., an element surrounding another one in the markup should be drawn around that one in the browser. According to this, the label should be the input's sibling, not it's parent. So option number two is arbitrary and confusing. Everyone that has read the Zen of Python will probably agree (Flat is better than nested, Sparse is better than dense, There should be one-- and preferably only one --obvious way to do it...).
Because of decisions like that from W3C and major browser vendors (allowing "whichever way you prefer to do it", instead of "do it the right way") is that the web is so messed up today and we developers have to deal with tangled and so diverse legacy code.
I usually go with the first two options. I've seen a scenario when the third option was used, when radio choices where embedded in labels and the css contained something like
label input {
vertical-align: bottom;
}
in order to ensure proper vertical alignment for the radios.
I greatly prefer to wrap elements inside my <label> because I don't have to generate the ids.
I am a Javascript developer, and React or Angular are used to generate components that can be reused by me or others. It would be then easy to duplicate an id in the page, leading there to strange behaviours.
Referring to the WHATWG (Writing a form's user interface) it is not wrong to put the input field inside the label. This saves you code because the for attribute from the label is no longer needed.
One thing you need to consider is the interaction of checkbox and radio inputs with javascript.
Using below structure:
<label>
<input onclick="controlCheckbox()" type="checkbox" checked="checkboxState" />
<span>Label text</span>
</label>
When user clicks on "Label text" controlCheckbox() function will be fired once.
But when input tag is clicked the controlCheckbox() function may be fired twice in some older browsers. That's because both input and label tags trigger onclick event attached to checkbox.
Then you may have some bugs in your checkboxState.
I've run into this issue lately on IE11. I'm not sure if modern browsers have troubles with this structure.
There are several advantages of nesting the inputs into a label, especially with radio/checkbox fields,
.unchecked, .checked{display:none;}
label input:not(:checked) ~ .unchecked{display:inline;}
label input:checked ~ .checked{display:inline;}
<label>
<input type="checkbox" value="something" name="my_checkbox"/>
<span class="unchecked">Not Checked</span>
<span class="checked">Is Checked</span>
</label>
As you can see from the demo, nesting the input field first followed by other elements allows,
The text to be clicked to activate the field
The elements following the input field to be dynamically styled according to the status of the field.
In addition, HTML std allows multiple labels to be associated with an input field, however this will confuse screen readers and one way to get round this is to nest the input field and other elements within a single label element.