ErrorSnapshotter

ErrorSnapshotter class is used to capture a screenshot of the page and a snapshot of the HTML when an error occurs during web crawling.

This functionality is opt-in, and can be enabled via the crawler options:

const crawler = new BasicCrawler({
  // ...
  statisticsOptions: {
    saveErrorSnapshots: true,
  },
});

Index

Constructors

• constructor

Properties

• BASE_MESSAGE
• MAX_ERROR_CHARACTERS
• MAX_FILENAME_LENGTH
• MAX_HASH_LENGTH
• SNAPSHOT_PREFIX

Methods

• captureSnapshot
• contextCaptureSnapshot
• generateFilename
• saveHTMLSnapshot

Constructors

constructor

• new ErrorSnapshotter(): ErrorSnapshotter

• Returns ErrorSnapshotter

Properties

staticreadonlyBASE_MESSAGE

BASE_MESSAGE: An error occurred = 'An error occurred'

staticreadonlyMAX_ERROR_CHARACTERS

MAX_ERROR_CHARACTERS: 30 = 30

staticreadonlyMAX_FILENAME_LENGTH

MAX_FILENAME_LENGTH: 250 = 250

staticreadonlyMAX_HASH_LENGTH

MAX_HASH_LENGTH: 30 = 30

staticreadonlySNAPSHOT_PREFIX

SNAPSHOT_PREFIX: ERROR_SNAPSHOT = 'ERROR_SNAPSHOT'

Methods

captureSnapshot

• captureSnapshot(error: ErrnoException, context: CrawlingContext<unknown, Dictionary>): Promise<{ htmlFileName?: string; screenshotFileName?: string }>

• Capture a snapshot of the error context.

  ---

  Parameters

  • error: ErrnoException

  • context: CrawlingContext<unknown, Dictionary>

  Returns Promise<{ htmlFileName?: string; screenshotFileName?: string }>

contextCaptureSnapshot

• contextCaptureSnapshot(context: BrowserCrawlingContext, fileName: string): Promise<undefined | SnapshotResult>

• Captures a snapshot of the current page using the context.saveSnapshot function. This function is applicable for browser contexts only. Returns an object containing the filenames of the screenshot and HTML file.

  ---

  Parameters

  • context: BrowserCrawlingContext

  • fileName: string

  Returns Promise<undefined | SnapshotResult>

generateFilename

• generateFilename(error: ErrnoException): string

• Generate a unique fileName for each error snapshot.

  ---

  Parameters

  • error: ErrnoException

  Returns string

saveHTMLSnapshot

• saveHTMLSnapshot(html: string, keyValueStore: KeyValueStore, fileName: string): Promise<undefined | string>

• Save the HTML snapshot of the page, and return the fileName with the extension.

  ---

  Parameters

  • html: string

  • keyValueStore: KeyValueStore

  • fileName: string

  Returns Promise<undefined | string>