what is crawl request

 

A crawl request is a request made by a webmaster or website owner to a search engine's crawler to visit and crawl a specific web page or URL on their website.

Search engine crawlers (also known as spiders, bots or robots) are programs that scan the web, discovering and indexing new pages, and updating the search engine's index with new or updated content. When a website is crawled, the search engine's crawler visits the website and analyses the content of the pages to determine what the website is about and how relevant it is to specific search queries.

A crawl request can be useful for ensuring that a new or updated page on your website is indexed quickly by search engines. If you have made changes to a page that you want search engines to know about, you can submit a crawl request to the search engine so that it will visit the updated page and reindex it. This can help to ensure that the updated content is reflected in search results as quickly as possible.

It's worth noting that submitting a crawl request does not guarantee that the search engine will crawl your page immediately, but it can speed up the process. In general, search engines will crawl pages based on their own algorithms and schedule, so it's important to ensure that your website is optimized for search engines and that you regularly publish new and relevant content.

Example that demonstrates how "switchMap" works:

"SwitchMap " working :

Here are the perfect example to understand working of "switchmap"

Suppose we have an input field that users can type into to search for books in a library. As the user types, we want to make an HTTP request to a server to get book suggestions based on the input. However, we don't want to make a new request for every keystroke, as that would be inefficient. Instead, we want to wait for the user to pause typing for a certain amount of time before making the request.

import statement for angular

import { fromEvent } from 'rxjs'; import { switchMap, debounceTime, distinctUntilChanged } from 'rxjs/operators'; import { ajax } from 'rxjs/ajax';

/* Get data from the search box */ const searchBox = document.getElementById('search-box');

const bookSuggestions$ = fromEvent(searchBox, 'input').pipe( debounceTime(500), // wait 500ms after each keystroke distinctUntilChanged(), // only emit if the value has changed switchMap((event) => { const searchQuery = (event.target as HTMLInputElement).value; return ajax.getJSON(`https://mylibrary.com/books?q=${searchQuery}`); }) ); bookSuggestions$.subscribe((books) => console.log(books));

In this example we first import all the necessary module in angular to achieve functionality of

switchmap. we first create an Observable from the input event of the search box using the fromEvent function. We then use debounceTime(500) to wait for 500ms after each keystroke before emitting the event. This ensures that we don't make a new request for every keystroke. We also use distinctUntilChanged() to only emit events if the search query has changed.

Finally, we use switchMap to transform the emitted events into an Observable that makes an HTTP request to the server using the ajax function. If a new event is emitted while the previous request is still in progress, switchMap will unsubscribe from the previous request and make a new one based on the new event. This ensures that we always get the most up-to-date search results.