pyhanko.pdf_utils.extensions module

class pyhanko.pdf_utils.extensions.DevExtensionMultivalued(value)

Bases: Enum

Setting indicating how an extension is expected to behave well w.r.t. the new mechanism for multivalued extensions in ISO 32000-2:2020.

ALWAYS = 1

Always serialise this extension as a multivalued extension.

NEVER = 2

Never serialise this extension as a multivalued extension.

MAYBE = 3

Make this extension single-valued whenever possible, but allow multiple values as well, e.g. when a different but non-comparable extension with the same prefix is already present in the file.

class pyhanko.pdf_utils.extensions.DeveloperExtension(prefix_name: NameObject, base_version: NameObject, extension_level: int, url: Optional[str] = None, extension_revision: Optional[str] = None, compare_by_level: bool = False, subsumed_by: Iterable[int] = (), subsumes: Iterable[int] = (), multivalued: DevExtensionMultivalued = DevExtensionMultivalued.MAYBE)

Bases: object

PDF developer extension designation.

prefix_name: NameObject

Registered developer prefix.

base_version: NameObject

Base version on to which the extension applies.

extension_level: int

Extension level.

url: Optional[str] = None

Optional URL linking to the extension’s documentation.

extension_revision: Optional[str] = None

Optional extra revision information. Not comparable.

compare_by_level: bool = False

Compare developer extensions by level number. If this value is True and a copy of this extension already exists in the target file with a higher level number, do not override it. If one exists with a lower level number, override it.

If this value is False, the decision is based on subsumed_by and subsumes.

Warning

It is generally not safe to assume that extension levels are used as a versioning system (i.e. that higher extension levels supersede lower ones), hence why the default is False.

subsumed_by: Iterable[int] = ()

List of extension levels that would subsume this one. If one of these is present in the extensions dictionary, attempting to register this extension will not override it.

Default value: empty.

Warning

This parameter is ignored if compare_by_level is True.

subsumes: Iterable[int] = ()

List of extensions explicitly subsumed by this one. If one of these is present in the extensions dictionary, attempting to register this extension will override it.

Default value: empty.

Warning

This parameter is ignored if compare_by_level is True.

multivalued: DevExtensionMultivalued = 3

Setting indicating whether this extension is expected to behave well w.r.t. the new mechanism for multivalued extensions in ISO 32000-2:2020.

as_pdf_object() → DictionaryObject

Format the data in this object into a PDF dictionary for registration into the /Extensions dictionary.

Returns

A generic.DictionaryObject.