@crawlee/http
Provides a framework for the parallel crawling of web pages using plain HTTP requests. The URLs to crawl are fed either from a static list of URLs or from a dynamic queue of URLs enabling recursive crawling of websites.
It is very fast and efficient on data bandwidth. However, if the target website requires JavaScript to display the content, you might need to use PuppeteerCrawler or PlaywrightCrawler instead, because it loads the pages using full-featured headless Chrome browser. This crawler downloads each URL using a plain HTTP request and doesn't do any HTML parsing.
The source URLs are represented using Request objects that are fed from RequestList or RequestQueue instances provided by the HttpCrawlerOptions.requestList or HttpCrawlerOptions.requestQueue constructor options, respectively.
If both HttpCrawlerOptions.requestList and HttpCrawlerOptions.requestQueue are used, the instance first processes URLs from the RequestList and automatically enqueues all of them to RequestQueue before it starts their processing. This ensures that a single URL is not crawled multiple times.
The crawler finishes when there are no more Request objects to crawl.
We can use the preNavigationHooks
to adjust gotOptions
:
preNavigationHooks: [
(crawlingContext, gotOptions) => {
// ...
},
]
By default, HttpCrawler
only processes web pages with the text/html
and application/xhtml+xml
MIME content types (as reported by the Content-Type
HTTP header), and skips pages with other content types. If you want the crawler to process other content types, use the HttpCrawlerOptions.additionalMimeTypes constructor option. Beware that the parsing behavior differs for HTML, XML, JSON and other types of content. For more details, see HttpCrawlerOptions.requestHandler.
New requests are only dispatched when there is enough free CPU and memory available, using the functionality provided by the AutoscaledPool class. All AutoscaledPool configuration options can be passed to the autoscaledPoolOptions
parameter of the HttpCrawler
constructor. For user convenience, the minConcurrency
and maxConcurrency
AutoscaledPool options are available directly in the HttpCrawler
constructor.
Example usage
import { HttpCrawler, Dataset } from '@crawlee/http';
const crawler = new HttpCrawler({
requestList,
async requestHandler({ request, response, body, contentType }) {
// Save the data to dataset.
await Dataset.pushData({
url: request.url,
html: body,
});
},
});
await crawler.run([
'http://www.example.com/page-1',
'http://www.example.com/page-2',
]);
Index
Crawlers
Functions
Interfaces
References
- AutoscaledPool
- AutoscaledPoolOptions
- BASIC_CRAWLER_TIMEOUT_BUFFER_SECS
- BasicCrawler
- BasicCrawlerOptions
- BasicCrawlingContext
- ClientInfo
- Configuration
- ConfigurationOptions
- CrawlerAddRequestsOptions
- CrawlerAddRequestsResult
- CrawlingContext
- CreateContextOptions
- CreateSession
- CriticalError
- Dataset
- DatasetConsumer
- DatasetContent
- DatasetDataOptions
- DatasetIteratorOptions
- DatasetMapper
- DatasetOptions
- DatasetReducer
- EnqueueLinksOptions
- EnqueueStrategy
- ErrorHandler
- EventManager
- EventType
- EventTypeName
- FinalStatistics
- GlobInput
- GlobObject
- IStorage
- KeyConsumer
- KeyValueStore
- KeyValueStoreIteratorOptions
- KeyValueStoreOptions
- LocalEventManager
- Log
- LogLevel
- Logger
- LoggerJson
- LoggerOptions
- LoggerText
- NonRetryableError
- ProxyConfiguration
- ProxyConfigurationFunction
- ProxyConfigurationOptions
- ProxyInfo
- PseudoUrl
- PseudoUrlInput
- PseudoUrlObject
- PushErrorMessageOptions
- QueueOperationInfo
- QueueOperationInfoOptions
- RecordOptions
- RegExpInput
- RegExpObject
- Request
- RequestHandler
- RequestList
- RequestListOptions
- RequestListSourcesFunction
- RequestListState
- RequestOptions
- RequestQueue
- RequestQueueOperationOptions
- RequestQueueOptions
- RequestTransform
- RetryRequestError
- Router
- RouterHandler
- Session
- SessionOptions
- SessionPool
- SessionPoolOptions
- SessionState
- Snapshotter
- SnapshotterOptions
- Source
- StatisticPersistedState
- StatisticState
- Statistics
- StorageClient
- StorageManagerOptions
- SystemInfo
- SystemStatus
- SystemStatusOptions
- UrlPatternObject
- createBasicRouter
- enqueueLinks
- log
- purgeDefaultStorages
Type Aliases
References
AutoscaledPool
AutoscaledPoolOptions
BASIC_CRAWLER_TIMEOUT_BUFFER_SECS
BasicCrawler
BasicCrawlerOptions
BasicCrawlingContext
ClientInfo
Configuration
ConfigurationOptions
CrawlerAddRequestsOptions
CrawlerAddRequestsResult
CrawlingContext
CreateContextOptions
CreateSession
CriticalError
Dataset
DatasetConsumer
DatasetContent
DatasetDataOptions
DatasetIteratorOptions
DatasetMapper
DatasetOptions
DatasetReducer
EnqueueLinksOptions
EnqueueStrategy
ErrorHandler
EventManager
EventType
EventTypeName
FinalStatistics
GlobInput
GlobObject
IStorage
KeyConsumer
KeyValueStore
KeyValueStoreIteratorOptions
KeyValueStoreOptions
LocalEventManager
Log
LogLevel
Logger
LoggerJson
LoggerOptions
LoggerText
NonRetryableError
ProxyConfiguration
ProxyConfigurationFunction
ProxyConfigurationOptions
ProxyInfo
PseudoUrl
PseudoUrlInput
PseudoUrlObject
PushErrorMessageOptions
QueueOperationInfo
QueueOperationInfoOptions
RecordOptions
RegExpInput
RegExpObject
Request
RequestHandler
RequestList
RequestListOptions
RequestListSourcesFunction
RequestListState
RequestOptions
RequestQueue
RequestQueueOperationOptions
RequestQueueOptions
RequestTransform
RetryRequestError
Router
RouterHandler
Session
SessionOptions
SessionPool
SessionPoolOptions
SessionState
Snapshotter
SnapshotterOptions
Source
StatisticPersistedState
StatisticState
Statistics
StorageClient
StorageManagerOptions
SystemInfo
SystemStatus
SystemStatusOptions
UrlPatternObject
createBasicRouter
enqueueLinks
log
purgeDefaultStorages
Type Aliases
HttpErrorHandler
Type parameters
- UserData: Dictionary = any
- JSONData: Dictionary = any
HttpHook
Type parameters
- UserData: Dictionary = any
- JSONData: Dictionary = any
HttpRequestHandler
Type parameters
- UserData: Dictionary = any
- JSONData: Dictionary = any