Attachments

Attachments are independent binary data attached to a document. They are file-like and require a name and the content type. As attachments do not have size restrictions, they are handled a bit differently than documents in the Document class. The content of the attachment isn’t cached in the instance at any point, thus data access require a network request.

Getting an Attachment instance

Given a document instance, we can get an Attachment instance using the attachment() member function. Unlike with Document instances, no data is retrieved from the sever yet.

butterfly = await database["butterfly"]
image_of_a_butterfly = butterfly.attachment("image.png")

Retrieving the Attachment content

To actually retrieve the data stored on the server, you have to use the fetch() method. Once the fetch method is called, the content_type member will be set to appropriate value passed from the server.

data = await image_of_a_butterfly.fetch()

Saving the content of an attachment

Reference

class aiocouch.attachment.Attachment(document, id)

A local representation for the referenced CouchDB document attachment

An instance of this class represents a local copy of an attachment of CouchDB documents.

Variables:

• id – the id of the attachment

• content_type – the content type of the attachment, only available after fetch() has been called.

Parameters:

• document (Document) – The correlated document

• id (str) – the id of the attachment

await delete()

Deletes the attachment from the server

Return type:

None

await exists()

Checks if the attachment exists on the server

Return type:

bool

Returns:

returns True if the attachment exists

await fetch()

Returns the content of the attachment

Return type:

bytes

Returns:

the attachment content

await save(data, content_type)

Saves the given attachment content on the server

Parameters:

• data (bytes) – the content of the attachment

• content_type (str) – the content type of the given data. (See Content type)

Return type:

None