But what if we’d like to insert an HTML string “as html”, with all tags and stuff working, in the same… " – insert html into elem, at the beginning,
"beforeend" – insert html into elem, at the… The second parameter is an HTML string, that is inserted “as HTML”.… Given some HTML in html, elem.insertAdjacentHTML(where, html) inserts it depending on the value of where… ; – insert html right after elem.
Usually the HTML-mode is used for webpages.… ="more html".… HTML of the element.The outerHTML property contains the full HTML of the element.… It puts the new HTML in its place instead.… With innerHTML we’ll have it inserted “as HTML”, with all HTML tags.
When the browser loads the page, it “reads” (another word: “parses”) the HTML and generates DOM objects… HTML attributes.In HTML, tags may have attributes.… These methods operate exactly with what’s written in HTML.… HTML-elements for JavaScript.… We want to read the value “as written” in HTML.
A built-in <template> element serves as a storage for HTML markup templates.… In theory, we could create any invisible element somewhere in HTML for HTML markup storage purposes.… First, its content can be any valid HTML, even if it normally requires a proper enclosing tag.… Summary.To summarize:
<template> content can be any syntactically correct HTML… The <template> tag is quite unique, because:
The browser checks HTML syntax inside it (as opposed
The backbone of an HTML document is tags.… According to the Document Object Model (DOM), every HTML tag is an object.… For instance, the top tag is always <html>.… > directive at the very beginning of HTML is also a DOM node.… …etc, everything in HTML has its place in DOM, even comments.
For instance, we need to find programming languages: HTML, PHP, Java or JavaScript.… The corresponding regexp: html|php|java(script)?.… To apply alternation to a chosen part of the pattern, we can enclose it in parentheses:
I love HTML|… CSS matches I love HTML or CSS.… I love (HTML|CSS) matches I love HTML or I love CSS.
We can create custom HTML elements, described by our class, with its own methods and properties, events… Once a custom element is defined, we can use it on par with built-in HTML elements.… That’s great, as HTML dictionary is rich, but not infinite.… That’s strange for an HTML element.… HTML Living Standard: https://html.spec.whatwg.org/#custom-elements.
Document events:
DOMContentLoaded – when the HTML is loaded and processed, DOM is fully built.… HTML-attribute.A handler can be set in HTML with an attribute named on<event>.… The event object is also available in HTML handlers
If we assign a handler in HTML, we can… Summary.There are 3 ways to assign event handlers:
HTML attribute: onclick="...".… HTML attributes are used sparingly, because JavaScript in the middle of an HTML tag looks a little bit
For instance, server-side scripts that download HTML pages and process them can also use the DOM.… Specifications
The BOM is a part of the general HTML specification.… The HTML spec at https://html.spec.whatwg.org is not only about the “HTML language” (tags, attributes… That’s “HTML in broad terms”.… HTML specification
Describes the HTML language (e.g. tags) and also the BOM (browser object model) –
Regexp for an “opening HTML-tag… Improved: /<[a-z][a-z0-9]*>/i
According to the standard, HTML tag name may have a digit at any… Regexp “opening or closing HTML-tag without attributes”: /<\/?… For instance, for HTML tags we could use a simpler regexp: <\w+>.… But as HTML has stricter restrictions for a tag name, <[a-z][a-z0-9]*> is more reliable.
This chapter is about sending HTML forms: with or without files, with additional fields and so on.… As you might have guessed, it’s the object to represent HTML form data.… The constructor is:
If HTML form element… Summary.FormData objects are used to capture HTML form and submit it using fetch or another network method… We can either create new FormData(form) from an HTML form, or create an object without a form at all,
This is the correct variant:
Resulthello.jsuser.jsindex.htmlIn the browser, if we talk about HTML pages… wait until the HTML document is fully ready (even if they are tiny and load faster than HTML), and then… As a side effect, module scripts always “see” the fully loaded HTML-page, including HTML elements below… Async scripts run immediately when ready, independently of other scripts or the HTML document.… “Special” module types like HTML/CSS modules are also supported.
The “script” tag.JavaScript programs can be inserted almost anywhere into an HTML document using the… used nowadays but can still be found in old code:
The type attribute: <script type=…>
The old HTML… Also, the modern HTML standard totally changed the meaning of this attribute.… Script files are attached to HTML with the src attribute:… Please note:
As a rule, only the simplest scripts are put into HTML
documentElement and body.The topmost tree nodes are available directly as document properties:
<html… That’s the DOM node of the <html> tag.… For instance, <head> and <body> are children of <html> element.… This detail may be useful when we want to travel up from an arbitrary element elem to <html>, but… There are also additional navigation properties for HTML forms.
Such snippet in an HTML markup looks like this:… We find code snippets in HTML and highlight them.
Now let’s go on.… For now it only matters that we fetch an HTML article from a webserver and display it on demand:… The new article HTML may contain code snippets… We can add/remove code snippets in HTML without thinking about it.
Here it is:
The HTML is like this:… In our case if we take a look inside the HTML, we can see nested tags inside <td>, like <strong… The HTML structure is flexible, we can add/remove buttons at any time.… We can add new ones to HTML at any moment.… Using the event delegation we “extended” HTML, added an attribute that describes a new behavior.
</textarea> holds its value as nested HTML, we should never use textarea.innerHTML to access it… It stores only the HTML that was initially on the page, not the current value.… text – the text inside the option,
value – the option value,
defaultSelected – if true, then selected HTML-attribute… The difference between defaultSelected and selected is that defaultSelected sets the HTML-attribute (
In modern websites, scripts are often “heavier” than HTML: their download size is larger, and processing… When the browser loads HTML and comes across a <script>...… example, the browser notices the script (and can start downloading it) only after it downloaded the full HTML… For long HTML documents, that may be a noticeable delay.… Instead, the browser will continue to process the HTML, build DOM.
information, we can use the root document element document.documentElement, that corresponds to the <html… DOCTYPE HTML> in HTML. Odd things are possible.
In modern HTML we should always write DOCTYPE.
Normally it goes upwards till <html>, and then to document object, and some events even reach window… capturing phase was invisible for us, because handlers added using on<event>-property or using HTML… If you click on <p>, then the sequence is:
HTML → BODY → FORM → DIV -> P (capturing phase,… the first listener):
P → DIV → FORM → BODY → HTML (bubbling phase, the second listener).… the event bubbles up from event.target to the root, calling handlers assigned using on<event>, HTML
They can be written right in a web page’s HTML and run automatically as the page loads.… For instance, in-browser JavaScript is able to:
Add new HTML to the page, change the existing content… There are at least three great things about JavaScript:
Full integration with HTML/CSS.… JavaScript has a unique position as the most widely-adopted browser language, fully integrated with HTML
Some features are well-supported and integrated into the modern HTML/DOM standard, while others are yet… Custom elements – to define custom HTML elements.
In this HTML, a click on a link doesn’t lead to navigation; the browser doesn’t do anything:… some CSS:
Menu items are implemented as HTML-links… But we should generally keep the semantic meaning of HTML elements.… Besides being “just a good thing”, that makes your HTML better in terms of accessibility.
That’s fine for simple scripts, inlined into HTML, but generally isn’t a good thing.… Also, when one reads JS code and doesn’t have HTML in view, it’s not obvious where the variable comes… the collection with elements that the pointer is over now (in nesting order: from the outermost <html
There’s also an autofocus HTML attribute that puts the focus onto an element by default when a page loads… Modern HTML… This can be changed using HTML-attribute tabindex.
The lifecycle of an HTML page has three important events:
DOMContentLoaded – the browser fully loaded… HTML, and the DOM tree is built, but external resources like pictures <img> and stylesheets may… not yet have loaded.
load – not only HTML is loaded, but also all the external resources: images, styles… DOMContentLoaded and scripts.When the browser processes an HTML-document and comes across a <script
For web-developers there are much better-known examples: HTML and XML documents.… In the HTML document, an HTML-tag may contain a list of:
Text pieces.
HTML-comments.… Other HTML-tags (that in turn may contain text pieces/comments or other tags etc).… Trees like HTML elements tree or the department tree from this chapter are also naturally recursive:
Also, there are tools like JSDoc 3 that can generate HTML-documentation from the comments.… Comments are also used for auto-documenting tools like JSDoc3: they read them and generate HTML-docs
tree.A DOM element can have two types of DOM subtrees:
Light tree – a regular DOM subtree, made of HTML… Shadow tree – a hidden DOM subtree, not reflected in HTML, hidden from prying eyes.
Here’s the similar code that causes user to download the dynamically created Blob, without any HTML:… In the previous example with the clickable HTML-link, we don’t call URL.revokeObjectURL(link.href), because
For browsers, timers are described in the timers section of HTML Living Standard.
setInterval.The setInterval… The HTML Living Standard says: “after five nested timers, the interval is forced to be at least 4 milliseconds
For instance, HTML has tags and attributes, JavaScript code has functions, variables, and so on.
Its HTML has two nested elements: the <div id="child"> is inside the <div id="… triggers, when the pointer moves from an element to its descendant, e.g. from #parent to #child in this HTML
Many built-in objects already exist, such as those that work with dates, errors, HTML elements, etc.
The event is the part of the HTML
, a call to event.composedPath() returns an array: [span, slot, div, shadow-root, user-card, body, html
The full HTML page with these frameworks and pow spec:… The HTML element <div id="mocha"> will be used by Mocha to output results.
some cases, when the absence of the element is normal, we’d like to avoid the error and just accept html
For instance, the function createMessageUnder(elem, html) below shows the message under elem:
Surely the user has access to HTML-source of the page, and can take the content from there, but not everyone
In the modern HTML standard there’s a section about Drag and Drop with special events such as dragstart
It must be sent exactly as HTTP-header: the browser will ignore it if found in HTML <meta> tag.
As an input value is a pure text, not HTML, there’s no need for such objects, everything’s much simpler… DOM spec: Range
Selection API
HTML spec: APIs for the text control selections
Summary.We covered two
The Sources panel has 3 parts:
The File Navigator pane lists HTML
Using setInterval.An animation can be implemented as a sequence of frames – usually small changes to HTML
…and so on…
For instance, we’d like to find HTML tags <.*?>, and process them.
For <body> and <html>.
For elements with position:fixed.
chapter Blob),
"document" – get as XML document (can use XPath and other XML methods) or HTML
For example, if we are getting values from HTML form fields, they are usually strings.
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