Request from HTTPS to HTTP (from safe to unsafe protocol).… →HTTP request, then send nothing.… "strict-origin" – send only the origin, not the Referer for HTTPS→HTTP requests.… "unsafe-url" – always send the full url in Referer, even for HTTPS→HTTP requests.… to HTTP, then no Referer).
Between these releases, the latest specification draft is at https://tc39.es/ecma262/.… You can find it at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference.… Just use “MDN [term]” in the query, e.g. https://google.com/search?… of support, e.g. to see which engines support modern cryptography functions: https://caniuse.com/#feat… =cryptography.
https://kangax.github.io/compat-table – a table with language features and engines that
At this stage we can check HTTP status, to see whether it is successful or not, check headers, but don… The promise rejects if the fetch was unable to make HTTP-request, e.g. network problems, or there’s no… Abnormal HTTP-statuses, such as 404 or 500 do not cause an error.… We can see HTTP-status in response properties:
status – HTTP status code, e.g. 200.
ok – boolean, true… if the HTTP status code is 200-299.
The HTML spec at https://html.spec.whatwg.org is not only about the “HTML language” (tags, attributes… Also, some parts have additional specs listed at https://spec.whatwg.org.… BOM (browser object model) – various browser functions: setTimeout, alert, location and so on, see https… Additionally, some classes are described separately at https://spec.whatwg.org/.… q=whatwg+localstorage, https://google.com?q=mdn+localstorage.
For instance, let’s try fetching http://example.com:… Then we make a <script> tag with src="http://another.com/weather.json?… For instance, if we request https://anywhere.com/request from https://javascript.info/page, the headers… That’s uncommon for HTTP-requests.… For example, fetch('http://another.com') does not send any cookies, even those (!)
It’s like HTTPS for websockets.… On the other hand, wss:// is WebSocket over TLS, (same as HTTPS is HTTP over TLS), the transport security… And that’s not HTTP at all.… WebSocket codes are somewhat like HTTP codes, but different.… ://site.com goes to the main HTTP-server.
XMLHttpRequest is a built-in browser object that allows to make HTTP requests in JavaScript.… request is synchronous, we’ll cover that a bit later.
user, password – login and password for basic HTTP… These three events are the most widely used:
load – when the request is complete (even if HTTP status… status code (a number): 200, 404, 403 and so on, can be 0 in case of a non-HTTP failure.
statusText… Just like fetch, it doesn’t send cookies and HTTP-authorization to another origin by default.
They are a part of the HTTP protocol, defined by the RFC 6265 specification.… Cookies are usually set by a web server using the response Set-Cookie HTTP header.… By default, if we set a cookie at http://site.com, then it also appears at https://site.com and vice… is accessed by HTTP, as http://site.com.… The full list of safe HTTP methods is in the RFC7231 specification.
These URLs all share the same origin:
http://site.com
http://site.com/
http://site.com/my/page.html… These ones do not:
http://www.site.com (another domain: www. matters)
http://site.org (another domain… : .org matters)
https://site.com (another protocol: https)
http://site.com:8080 (another port: 8080)… special properties:
data
The data from postMessage.
origin
The origin of the sender, for instance http… triggers the message event with special properties:
origin – the origin of the sender window (like http
language appear regularly, they are analyzed and, if considered worthy, are appended to the list at https… A good page to see the current state of support for language features is https://compat-table.github.io… Good resources that show the current state of support for various features:
https://compat-table.github.io… /compat-table/es6/ – for pure JavaScript.
https://caniuse.com/ – for browser-related functions.
list would require a lot of space, so here are the references:
List all properties by a character: https… List all characters by a property: https://unicode.org/cldr/utility/list-unicodeset.jsp.… Short aliases for properties: https://www.unicode.org/Public/UCD/latest/ucd/PropertyValueAliases.txt.… A full base of Unicode characters in text format, with all properties, is here: https://www.unicode.org
One-directional: only server sends data
Binary and text data
Only text
WebSocket protocol
Regular HTTP… Besides, it’s a plain old HTTP, not a new protocol.… If the server wants the browser to stop reconnecting, it should respond with HTTP status 204.… Also, there will be no reconnection if the response has an incorrect Content-Type or its HTTP… the connection is open.
error – the connection could not be established, e.g. the server returned HTTP
Built-in events mostly have composed: true, as described in the relevant specifications:
UI Events https… Touch Events https://w3c.github.io/touch-events.… Pointer Events https://www.w3.org/TR/pointerevents.
…And so on.
Please note that we can’t get HTTP… So, e.g. a script at https://facebook.com can’t read the user’s mailbox at https://gmail.com.
hash starts with the hash character #
there may be also user and password properties if HTTP authentication… is present: http://login:password@site.com (not painted above, rarely used).… …”.Let’s say we want to create a url with given search params, for instance, https://google.com/search
A page from http://anysite.com which a user has opened must not be able to access another browser tab… with the URL http://gmail.com, for example, and steal information from there.… Though possible, it requires explicit agreement (expressed in HTTP headers) from the remote side.
DOM: https://dom.spec.whatwg.org/#shadow-trees
Compatibility: https://caniuse.com/#feat=shadowdomv1
Shadow
The full specification of the <select> element is available in the specification https… Specification: https://html.spec.whatwg.org/multipage/forms.html.
HTML Living Standard: https://html.spec.whatwg.org/#custom-elements.… Compatiblity: https://caniuse.com/#feat=custom-elementsv1.… There’s a polyfill https://github.com/webcomponents/polyfills/tree/master/packages/webcomponentsjs.
to retrieve commits in the same, paginated fashion:
We should make a request to fetch in the form https… The initial URL is https://api.github.com/repos/<repo>/commits, and the next page will be in the… The next page URL may look like https://api.github.com/repositories/93253246/commits?page=2.
You can find the current state of support at https://caniuse.com/#feat=bigint.
It must be sent exactly as HTTP-header: the browser will ignore it if found in HTML <meta> tag.… So, <meta http-equiv="X-Frame-Options"...> won’t do anything.
For screenshotting a page, we can use a library such as https… It’s outside of our scope here, but here’s an example, and you can read more at https://developer.mozilla.org
-- https://github.com/ChromeDevTools/devtools-frontend/blob/master/front_end/Images/src/largeIcons.svg… The full manual is at https://developers.google.com/web/tools/chrome-devtools.
The native interface to IndexedDB, described in the specification https://www.w3.org/TR/IndexedDB, is… We can also use async/await with the help of a promise-based wrapper, like https://github.com/jakearchibald… Use proper HTTP caching headers to avoid loading the old code, so that you’ll never have such problems… Let’s use a thin promise wrapper https://github.com/jakearchibald/idb further in this chapter.… The examples are at the lib page https://github.com/jakearchibald/idb.
You can read more information about JSDoc at https://jsdoc.app.
Why is the task solved this way?
In the latter case, stylesheets are HTTP-cached, so they are not redownloaded for multiple components
There are also web-services that provide error-logging for such cases, like https://errorception.com… or https://www.muscula.com.
loading after the page is complete)
…or after an async script (if an async script is short or was in HTTP-cache
Also unlike cookies, the server can’t manipulate storage objects via HTTP headers.
For instance, we can do it on the site https://cubic-bezier.com.… You can find a longer list of CSS properties and which stages they trigger at https://csstriggers.com
See https://eslint.org/docs/user-guide/getting-started for more details about installation.
A polyfill may be required, such as https://github.com/ljharb/String.prototype.matchAll.
The great pack of articles about V8 can be found at https://mrale.ph.
exists a special navigator.sendBeacon(url, data) method for such needs, described in the specification https
There’s an extensive documentation about Chrome Developer Tools at https://developers.google.com/web/
Modules work only via HTTP(s), not locally
If you try to open a web-page locally, via file
For instance, HTMLInputElement is documented at https://html.spec.whatwg.org/#htmlinputelement.