Interface FreezeDryConfig

Whether to note the snapshotting time and the document's URL in an extra meta and link tag.

Default Value

true

Whether to preserve the value of an element attribute if its URLs are inlined, by noting it as a new data-original-... attribute. For example, <img src="bg.png"> would become <img src="data:..." data-original-src="bg.png">. Note this is an unstandardised workaround to keep URLs of subresources available; unfortunately URLs inside stylesheets are still lost.

Override the snapshot time (only relevant when addMetadata is true). Mainly intended for testing purposes.

Add a <meta> tag with the given content security policy to the snapshot. The default value only allows loading inline resources and data: URLs, no external resources.

The value put into the <meta charset="…"> element of the snapshot.

If you will store/serve the returned string using an encoding other than UTF8, pass its name here; or pass null or an empty string to omit the declaration altogether.

Default Value

'utf-8'

Maximum time (in milliseconds) spent on fetching the page’s subresources. The resulting HTML will have only succesfully fetched subresources inlined.

Default Value

Infinity

Signal to abort subresource fetching at any moment. As with timeout, the resulting HTML will have only succesfully fetched subresources inlined.

Custom function for fetching resources; should be API-compatible with the global fetch(), but may also resolve to an object { blob, url } instead of a Response.

This option is ignored if a custom processSubresource is given.

For aborting to work (e.g. via the timeout or signal options), this callback must respect its signal parameter.

Transformations to apply on the document and each subresource.

To also perform the default transformations, make this callback run resource.dry().

This option is ignored if a custom processSubresource is given.

Callback to determine the replacement URL for a (processed, dried) subresource; defaults to creating a data: URL.

This option is ignored if a custom processSubresource is given.

Callback invoked for each of doc’s subresources.

The default behaviour is to recursively fetch and ‘dry’ subresources and turn each into a data: URL. Those individual steps can be customised by the other subresource handling options: fetchResource, dryResource, and newUrlForResource.

If those options are not flexible enough, a completely custom processResource might be a solution. Other subresource handling options are then ignored.

Example

This is a simplification of what the default freezeDry implementation does (assuming other options are kept at their defaults too):

async processSubresource(link, recurse) {
  link.resource ||= await Resource.fromLink(link)   // fetch the subresource
  await link.resource.processSubresources(recurse)  // recurse into its links
  await link.resource.dry()                         // dry the subresource
  link.target = blobToDataUrl(link.resource.blob)   // inline its content in the link
}

URL to override doc.URL.

Its value will influence the expansion of relative URLs, and is useful for cases where the document was constructed dynamically (e.g. using DOMParser).

Overrides the object providing global DOM interfaces (instead of globalThis/window). Only relevant when freezeDry is not run ‘in’ but ‘on’ a DOM (e.g. in NodeJS on JSDOM).