@crawlee/templates - npm Package Versions

3.0.0 (2022-07-13)

This section summarizes most of the breaking changes between Crawlee (v3) and Apify SDK (v2). Crawlee is the spiritual successor to Apify SDK, so we decided to keep the versioning and release Crawlee as v3.

Crawlee vs Apify SDK

Up until version 3 of apify, the package contained both scraping related tools and Apify platform related helper methods. With v3 we are splitting the whole project into two main parts:

• Crawlee, the new web-scraping library, available as crawlee package on NPM
• Apify SDK, helpers for the Apify platform, available as apify package on NPM

Moreover, the Crawlee library is published as several packages under @crawlee namespace:

• @crawlee/core: the base for all the crawler implementations, also contains things like Request, RequestQueue, RequestList or Dataset classes
• @crawlee/basic: exports BasicCrawler
• @crawlee/cheerio: exports CheerioCrawler
• @crawlee/browser: exports BrowserCrawler (which is used for creating @crawlee/playwright and @crawlee/puppeteer)
• @crawlee/playwright: exports PlaywrightCrawler
• @crawlee/puppeteer: exports PuppeteerCrawler
• @crawlee/memory-storage: @apify/storage-local alternative
• @crawlee/browser-pool: previously browser-pool package
• @crawlee/utils: utility methods
• @crawlee/types: holds TS interfaces mainly about the StorageClient

Installing Crawlee

As Crawlee is not yet released as latest, we need to install from the next distribution tag!

Most of the Crawlee packages are extending and reexporting each other, so it's enough to install just the one you plan on using, e.g. @crawlee/playwright if you plan on using playwright - it already contains everything from the @crawlee/browser package, which includes everything from @crawlee/basic, which includes everything from @crawlee/core.

npm install crawlee@next

Or if all we need is cheerio support, we can install only @crawlee/cheerio

npm install @crawlee/cheerio@next

When using playwright or puppeteer, we still need to install those dependencies explicitly - this allows the users to be in control of which version will be used.

npm install crawlee@next playwright
# or npm install @crawlee/playwright@next playwright

Alternatively we can also use the crawlee meta-package which contains (re-exports) most of the @crawlee/* packages, and therefore contains all the crawler classes.

Sometimes you might want to use some utility methods from @crawlee/utils, so you might want to install that as well. This package contains some utilities that were previously available under Apify.utils. Browser related utilities can be also found in the crawler packages (e.g. @crawlee/playwright).

Full TypeScript support

Both Crawlee and Apify SDK are full TypeScript rewrite, so they include up-to-date types in the package. For your TypeScript crawlers we recommend using our predefined TypeScript configuration from @apify/tsconfig package. Don't forget to set the module and target to ES2022 or above to be able to use top level await.

The @apify/tsconfig config has noImplicitAny enabled, you might want to disable it during the initial development as it will cause build failures if you left some unused local variables in your code.

{
    "extends": "@apify/tsconfig",
    "compilerOptions": {
        "module": "ES2022",
        "target": "ES2022",
        "outDir": "dist",
        "lib": ["DOM"]
    },
    "include": [
        "./src/**/*"
    ]
}

Docker build

For Dockerfile we recommend using multi-stage build, so you don't install the dev dependencies like TypeScript in your final image:

# using multistage build, as we need dev deps to build the TS source code
FROM apify/actor-node:16 AS builder

# copy all files, install all dependencies (including dev deps) and build the project
COPY . ./
RUN npm install --include=dev \
    && npm run build

# create final image
FROM apify/actor-node:16
# copy only necessary files
COPY --from=builder /usr/src/app/package*.json ./
COPY --from=builder /usr/src/app/README.md ./
COPY --from=builder /usr/src/app/dist ./dist
COPY --from=builder /usr/src/app/apify.json ./apify.json
COPY --from=builder /usr/src/app/INPUT_SCHEMA.json ./INPUT_SCHEMA.json

# install only prod deps
RUN npm --quiet set progress=false \
    && npm install --only=prod --no-optional \
    && echo "Installed NPM packages:" \
    && (npm list --only=prod --no-optional --all || true) \
    && echo "Node.js version:" \
    && node --version \
    && echo "NPM version:" \
    && npm --version

# run compiled code
CMD npm run start:prod

Browser fingerprints

Previously we had a magical stealth option in the puppeteer crawler that enabled several tricks aiming to mimic the real users as much as possible. While this worked to a certain degree, we decided to replace it with generated browser fingerprints.

In case we don't want to have dynamic fingerprints, we can disable this behaviour via useFingerprints in browserPoolOptions:

const crawler = new PlaywrightCrawler({
   browserPoolOptions: {
       useFingerprints: false,
   },
});

Session cookie method renames

Previously, if we wanted to get or add cookies for the session that would be used for the request, we had to call session.getPuppeteerCookies() or session.setPuppeteerCookies(). Since this method could be used for any of our crawlers, not just PuppeteerCrawler, the methods have been renamed to session.getCookies() and session.setCookies() respectively. Otherwise, their usage is exactly the same!

Memory storage

When we store some data or intermediate state (like the one RequestQueue holds), we now use @crawlee/memory-storage by default. It is an alternative to the @apify/storage-local, that stores the state inside memory (as opposed to SQLite database used by @apify/storage-local). While the state is stored in memory, it also dumps it to the file system, so we can observe it, as well as respects the existing data stored in KeyValueStore (e.g. the INPUT.json file).

When we want to run the crawler on Apify platform, we need to use Actor.init or Actor.main, which will automatically switch the storage client to ApifyClient when on the Apify platform.

We can still use the @apify/storage-local, to do it, first install it pass it to the Actor.init or Actor.main options:

@apify/storage-local v2.1.0+ is required for Crawlee

import { Actor } from 'apify';
import { ApifyStorageLocal } from '@apify/storage-local';

const storage = new ApifyStorageLocal(/* options like `enableWalMode` belong here */);
await Actor.init({ storage });

Purging of the default storage

Previously the state was preserved between local runs, and we had to use --purge argument of the apify-cli. With Crawlee, this is now the default behaviour, we purge the storage automatically on Actor.init/main call. We can opt out of it via purge: false in the Actor.init options.

Renamed crawler options and interfaces

Some options were renamed to better reflect what they do. We still support all the old parameter names too, but not at the TS level.

• handleRequestFunction -> requestHandler
• handlePageFunction -> requestHandler
• handleRequestTimeoutSecs -> requestHandlerTimeoutSecs
• handlePageTimeoutSecs -> requestHandlerTimeoutSecs
• requestTimeoutSecs -> navigationTimeoutSecs
• handleFailedRequestFunction -> failedRequestHandler

We also renamed the crawling context interfaces, so they follow the same convention and are more meaningful:

• CheerioHandlePageInputs -> CheerioCrawlingContext
• PlaywrightHandlePageFunction -> PlaywrightCrawlingContext
• PuppeteerHandlePageFunction -> PuppeteerCrawlingContext

Context aware helpers

Some utilities previously available under Apify.utils namespace are now moved to the crawling context and are context aware. This means they have some parameters automatically filled in from the context, like the current Request instance or current Page object, or the RequestQueue bound to the crawler.

Enqueuing links

One common helper that received more attention is the enqueueLinks. As mentioned above, it is context aware - we no longer need pass in the requestQueue or page arguments (or the cheerio handle $). In addition to that, it now offers 3 enqueuing strategies:

• EnqueueStrategy.All ('all'): Matches any URLs found
• EnqueueStrategy.SameHostname ('same-hostname') Matches any URLs that have the same subdomain as the base URL (default)
• EnqueueStrategy.SameDomain ('same-domain') Matches any URLs that have the same domain name. For example, https://wow.an.example.com and https://example.com will both be matched for a base url of https://example.com.

This means we can even call enqueueLinks() without any parameters. By default, it will go through all the links found on current page and filter only those targeting the same subdomain.

Moreover, we can specify patterns the URL should match via globs:

const crawler = new PlaywrightCrawler({
    async requestHandler({ enqueueLinks }) {
        await enqueueLinks({
            globs: ['https://apify.com/*/*'],
            // we can also use `regexps` and `pseudoUrls` keys here
        });
    },
});

Implicit RequestQueue instance

All crawlers now have the RequestQueue instance automatically available via crawler.getRequestQueue() method. It will create the instance for you if it does not exist yet. This mean we no longer need to create the RequestQueue instance manually, and we can just use crawler.addRequests() method described underneath.

We can still create the RequestQueue explicitly, the crawler.getRequestQueue() method will respect that and return the instance provided via crawler options.