I know that the textarea doesn't support the functionality of pattern, however if I set the pattern variable in html, its still present in the browser.
So I have to execute the pattern verification in js anyways, but is it OK for me to store the pattern in the pattern attribute? As opposed to data-pattern or something, for consistency with the input elements?
You should use data-* attributes for extra attributes and since textarea tag does not support the pattern attribute then adding it like adding value to div.
Hope this helps.
Custom attribute is suppose to have the data- prefix, so I recommend to use that or you could ran into issues when validating your code.
And what happens if such an attribute suddenly become a standard attribute?
More to read:
https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes
https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes#data-*
https://www.w3.org/TR/2011/WD-html5-20110525/elements.html#embedding-custom-non-visible-data-with-the-data-attributes
Related
Is there any way to add a format to a input tag that the user has to use.
As an example I would like the user to input a text of the format:
int:int
or
2:1
Is there any way of doing this in html without writing a validation code in javascript?
Edit: I would be willing to use an extra library
You are able to add an attribute pattern="" which uses Regex to validate the input format. In your case if you want any integer followed by ':' followed by other integer, the solution is:
<input pattern="\d+[:]\d+" title="{message_text}" />
Edit: added title="" attribute
You can do this with Vue.js by adding v-model.numer=“” in the html. This would be using Vue, a external library that would handle it all for you.
For vanilla HTML, You can also use type=“number” in your input tag, and most browsers support this. The ones that don’t will default to type of text. More info here: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/number
I know that custom tags need to have a "-". And I kwnow that custom attributes need the "data-" prefix. But what about custom attribute on a custom tag?
If I define a custom HTML tag/element, such as <x-sososlik></x-sososlik>.
And I need some custom attributes on it. For example: hair-color.
Does that attribute need the data-* prefix?
<x-sososlik hair-color="green"></x-sososlik>
-or-
<x-sososlik data-hair-color="green"></x-sosolik>
The question is more about "what is the CORRECT way", because it works with both.
I'm asking because I cannot find that information.
I need to know it because I'm trying to shorten the attribute names on existing project, in the real code there a lot of them.
No, you don't need to use the data- prefix on an autonomous custom element (as opposed to a customized built-in element). As specified in the WHATWG HTML standard:
Any namespace-less attribute that is relevant to the element's functioning, as determined by the element's author, may be specified on an autonomous custom element, so long as the attribute name is XML-compatible and contains no ASCII upper alphas. The exception is the is attribute, which must not be specified on an autonomous custom element (and which will have no effect if it is).
I have seen this code from the tutorial that I'm studying. I searched for the purpose of the p attribute inside the li tag but found no answer. What is the purpose of that p attribute inside the li tag?
$msgs .= "<li p=\"$no_of_paginations\" class=\"inactive\">Last</li>";
The purpose cannot be inferred from the code snippet. As such, the attribute, being not defined in any HTML specification or draft or browser-specific extension, has no effect beyond being stored as data into the p element node in the document tree.
Such an attribute, though invalid by the specs, can be used like any other attribute in styling (e.g. attribute selector .p) in CSS or in scripting. In this case, it is probable, but by no means certain, that the attribute is meant to be used in scripting to carry a number as its value, with that number inserted with some server-side code, so that this value can be accessed in client-side scripting, as relating to a specific element.
The recommended way is to use data-* attributes instead, such as data-p, to avoid any risk of clashing with attribute names that might be introduced in some future HTML version.
The default HTML(whichever version) namespace doesn't have a purpose for "p" inside a li tag. If there's another namespace declared then that's where it's from. Other than that, it's not valid by w3 standards.
It should be a custom attribute to use in JavaScript codes to get something.
That is just a custom tag used in some javascript functions
How to add a custom attribute to a HTML control.
<input type="text" validate="xyz"></input>
I want to add a new attribute to the HTML control. validate here is the custom attribute.
Just add it.
HTML will ignore attributes it doesn't "know" about, so long as the markup is valid.
If you're using html5, you can use:
data-customAttributeName="whatever value"
The data- prefix is mandatory, but you can follow it up with anything you like (so long as it's a valid html character string (a-z, 0-9, underscore and hyphen1).
Beyond that, though, it's of little importance since html will ignore attributes it doesn't understand or simply can't parse. Custom attributes will likely, though, throw validation errors (unless you define and specify a custom DTD).
There's probably others, but I can't remember exactly.
Like a tag that I can use to store some necessary info? But really isn’t required or used by the HTML? Works like the tag attribute for objects on Visual Basic?
Up until HTML5 no. With HTML 5 there is provision for this with the data-* attribute.
For example:-
<div id="myStuff" data-mydata="here is my data">
In current technology there is no "official" away to do this. However all browsers allow you to add any arbitary attribute to a HTML element so in HTML4 you can do this:-
<div id="myStuff" data-mydata="here is my data">
Which as you can see is identical but not offically sactioned and if you want strict XHMTL compliance will be considered "broken".
You can access the attribute just as you would any other:-
var mydata = document.getElementById("myStuff").getAttribute("data-mydata");
You could perhaps use the html5 data-* attributes? It'll fail validation on html4, but it is still probably the best option...
If you're storing data to use in javascript, you can also use something like jQuery's Metadata plugin. Basically, you can store data within the element's class="" attribute, like so:
<div id="aaa" class="class1 class2 class3 { type: 'food', color: 'green' }"></div>
Then in javascript:
alert($('#aaa').metadata().color) // "green"
Other kits use the title or rel attributes to store data. While this is more validation friendly, it may or may not be better than using AnthonyWJones' answer of just using non-standard attributes. It'll "break" validation, but then again according to Dojo, custom attributes are perfectly valid HTML, even if they don't validate against a DTD.
So no - there isn't a single well accepted specific attribute where you can dump all data. All existing attributes are for specific uses. But you can either 1) create your own attributes, or 2) coopt an existing tag to reuse for your purposes. Just wanted to point out the alternative.
Have a look at www.htmlref.com or W3C for the used attributes.
Other than those you can just add your own, they will render and they will be accessible via code for instance in C# you can access a controls attribute collection.
Control.Attributes["MyCustomAttribute"] = "Hello World";
there’s rel and rev attributes, which work in elements with an href-attribute. they have a semantic meaning, but are often abused as an attribute to store additional information