request-group-cheerio v1.4.0

Cheerio Request ( additionally with Request-Group functionality )

This library provides a simple way to use Cheerio to pull information from a web page. It simply sets up the request and creates the cheerio interface for you automatically. Additionally plugs right into the RequestGroup library giving you the ability to scrape multiple web pages as fast as you want.

Installing

npm install request-group-cheerio

Building

git clone https://github.com/GabrieleNunez/request-group-cheerio.git
cd request-group-cheerio
npm install
npm run build

Example ( Requesting a webpage)

import CheerioRequest from 'request-group-cheerio';

// create the request
let cheerioRequest: CheerioRequest = new CheerioRequest('https://github.com/GabrieleNunez/request-group');

// run the request and after its done parse the page
cheerioRequest.run().then((): void => {
    let $: CheerioStatic = cheerioRequest.getPage();
    console.log('Parsing: ' + cheerioRequest.getUrl());
    $('table.files td.message').each((index: number, element: CheerioElement): void => {
        let txt: string = $(element).text();
        console.log(txt.trim());
    });
    console.log('Request completed');
});

Example ( Scraping multiple web pages )

// index.ts
import CheerioRequest from 'request-group-cheerio';
import { RequestGroup, Request } from 'request-group';

function cheerioExample(): Promise<void> {
    return new Promise(
        async (resolve): Promise<void> => {
            // create our Request Group object
            let requestGroup: RequestGroup<CheerioStatic> = new RequestGroup<CheerioStatic>(2, 1000);

            // hook in a callback that way we can read and manipulate the page data
            requestGroup.setRequestComplete(
                (request: Request<CheerioStatic>): Promise<void> => {
                    return new Promise((requestResolve): void => {
                        let $: CheerioStatic = request.getPage();

                        console.log(request.getMetadata<string>('request-name') + ' Looping through messages');
                        console.log(
                            request.getMetadata<string>('request-name') +
                                ' Total Messages: ' +
                                $('table.files td.message').length,
                        );

                        $('table.files td.message').each((index: number, element: CheerioElement): void => {
                            console.log(request.getMetadata<string>('request-name') + ' Iteration: ' + index);
                            let txt: string = $(element)
                                .text()
                                .trim();

                            if (txt.length > 0) {
                                console.log(request.getMetadata<string>('request-name') + ': ' + txt);
                            }
                        });

                        requestResolve();
                    });
                },
            );

            // these are the things we want to crawl
            let urls: string[] = [
                'https://github.com/GabrieleNunez/request-group',
                'https://github.com/GabrieleNunez/bronco',
                'https://github.com/GabrieleNunez/thecoconutcoder.com',
                'https://github.com/GabrieleNunez/webcam.js',
            ];

            // loop through our urls and then add them into the queue
            for (var i = 0; i < urls.length; i++) {
                console.log('Adding: ' + urls[i]);
                let cheerioRequest: CheerioRequest = new CheerioRequest(urls[i]);
                let requestName: string | undefined = urls[i].split('/').pop();

                // just in case sanity check
                if (requestName === undefined) {
                    requestName = 'unknown-' + i;
                }

                cheerioRequest.setMetadata<string>('request-name', requestName as string);
                cheerioRequest.setMetadata<number>('request-index', i);

                // queue up the request we just made
                requestGroup.queue(cheerioRequest);
            }

            console.log('Letting request queue run');
            await requestGroup.run();

            console.log('This request queue has completed');
            resolve();
        },
    );
}

// demonstrate using cheerio for request
cheerioExample().then((): void => {
    console.log('Completed');
});