Metalink-author

A library for generating Metalink files. Metalink is a format for describing where files can be downloaded. The RFC is available here: https://tools.ietf.org/html/rfc5854.

This library does not support the full Metalink format, but it's easily extensible by adding classes for each property supported in the RFC. I've only implemented the ones I needed for the project that I built this tool for.

Usage

This code is in example.py:

from MetalinkAuthor.MetalinkAuthor import MetalinkEntry, MetalinkDocument, MetalinkProperties

print(MetalinkDocument()\
      .addEntry(
        MetalinkEntry("somefile.mov")\
        .addProperty(MetalinkProperties.SizeProperty(100 * 1000 * 100))\
        .addProperty(MetalinkProperties.URLProperty("https://example.com"))\
        .addProperty(MetalinkProperties.HashProperty("123456789ABCDEF"))
      )\
      .addEntry(
        MetalinkEntry("somefile-2.mov")\
        .addProperty(MetalinkProperties.SizeProperty(200 * 1000 * 100))\
        .addProperty(MetalinkProperties.URLProperty("https://example.com/1"))\
        .addProperty(MetalinkProperties.HashProperty("ABCDEFG-12345"))
      ).tostring()
     )

Extending

I have only supported a few properties that I needed for a project, but to make this fully support the Metalink spec, this just needs appropriate subclasses added to MetalinkAuthor/MetalinkProperties.py folder. Most of them are extremely basic. If it's just a property that has a tag with text content, you can just set the class property "key". For instance:

class LanguageProperty(BasicProperty):
    key = "language"


class DescriptionProperty(BasicProperty):
    key = "description"

For slightly more complicated elements, like the HashProperty, which has an attribute, you may need to override the constructor. It's only a couple more lines of code:

class HashProperty(BasicProperty):
    key = "hash"

    # Override to require a string value and allow an optional hash_type
    def __init__(self, value: str, hash_type="md5"):
        super(HashProperty, self).__init__(value)
        super(HashProperty, self).setAttribute("type", hash_type)