Crate webarchive

Expand description

Utilities for working with Apple’s Web Archive file format, as produced by Safari 2 or later on macOS, Safari 4 or later on Windows, or Safari 13 or later on iOS and iPadOS.

Why Web Archive?

Web Archive files have been around since 2005, and are a way to save an entire web page, and all associated resources involved in displaying it, as a single file which can be saved to disk, reviewed or shared regardless of changes, removals or the state of the server which originally served it.

While not well supported outside of Apple platforms, and not supported by iOS until iOS 13 in 2019, the Web Archive is one of few formats designed for a user to simply open a page and expect it to work as the original did. One which came closest is MHTML, supported in older versions of Microsoft’s Internet Explorer and with a similar approach to Web Archive, representing a web page in its entirety.

Alternatives aimed at professional or semi-professional archives work, such as WARC instead represent an entire browsing session and associated subresources, but require specialised software to view, and do not have the concept of a “main” page or resource. Web Archives, by contrast, open in a normal web browser and do not require the user to know which URL to select.

Okay, so what’s the goal?

I aim for this to be an ergonomic API for reading, creating, and converting Web Archive files, and to expand the included command line utility to allow bi-directional conversion between common formats and Web Archives.

Reading a webarchive

use webarchive::WebArchive;

let archive: WebArchive = webarchive::from_file("fixtures/psxdatacenter.webarchive")?;

/// main_resource is the resource which is opened by default
assert_eq!(
    archive.main_resource.url,
    "http://psxdatacenter.com/ntsc-j_list.html"
);
assert_eq!(archive.main_resource.mime_type, "text/html");
assert_eq!(
    archive.main_resource.text_encoding_name,
    Some("UTF-8".to_string())
);
assert_eq!(archive.main_resource.data.len(), 2171);
assert!(archive.subresources.is_none());

/// subframe_archives contains additional WebArchives for frames
assert!(archive.subframe_archives.is_some());
let subframe_archives = archive.subframe_archives.unwrap();
assert_eq!(subframe_archives.len(), 4);

assert_eq!(
    subframe_archives[0].main_resource.url,
    "http://psxdatacenter.com/banner.html"
);
assert_eq!(subframe_archives[0].main_resource.mime_type, "text/html");
assert_eq!(
    subframe_archives[0].main_resource.text_encoding_name,
    Some("UTF-8".to_string())
);
assert_eq!(subframe_archives[0].main_resource.data.len(), 782);

/// subresources are the files referenced by a given frame
assert!(subframe_archives[0].subresources.is_some());
let subresources = subframe_archives[0].subresources.as_ref().unwrap();
assert_eq!(subresources.len(), 2);

assert_eq!(
    subresources[0].url,
    "http://psxdatacenter.com/images/texgrey.jpg"
);
assert_eq!(subresources[0].mime_type, "image/jpeg");
assert!(subresources[0].text_encoding_name.is_none());
assert_eq!(subresources[0].data.len(), 107128);

Creating a webarchive

use webarchive::{WebArchive, WebResource};

let resource = WebResource {
    url: "about:hello".to_string(),
    data: "hello world".as_bytes().to_vec(),
    mime_type: "text/plain".to_string(),
    text_encoding_name: Some("utf-8".to_string()),
    frame_name: None,
    response: None,
};

let archive = WebArchive {
    main_resource: resource,
    subresources: None,
    subframe_archives: None,
};

let mut buf: Vec<u8> = Vec::new();

webarchive::to_writer_xml(&mut buf, &archive)?;

assert_eq!(
    String::from_utf8(buf)?,
    r#"<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>WebMainResource</key>
	<dict>
		<key>WebResourceData</key>
		<data>
		aGVsbG8gd29ybGQ=
		</data>
		<key>WebResourceURL</key>
		<string>about:hello</string>
		<key>WebResourceMIMEType</key>
		<string>text/plain</string>
		<key>WebResourceTextEncodingName</key>
		<string>utf-8</string>
	</dict>
</dict>
</plist>"#
);