User:Alsroot/trash/Object Bundles


Summary

  • package Journal objects to bundles to preserve sugar related metadata
  • support composite Journal objects e.g. in case of library bundles instead of having .xol in Journal and unpacked files in ~/Library, all library files will be represented by one Journal entry, could be opened in Browse([Metadata]/mime_type should be text/html for that purpose) and could be transformed back to .xo on demand(e.g. for uploading library in Browse's pick-file field).

Owner

Current status

  • Targeted release: 0.86
  • Last updated: Tue Jul 21 02:18:17 UTC 2009
  • Percentage of completion: 0%

Detailed Description

This feature is a first approach to unified format for all types of bundles(in 0.86 it will support only Journal entries and new library bundles).

Bundle files hierarchy

  • MANIFEST EOL-terminalted list of files inside bundle
  • METADATA file in INI format which describes bundle

METADATA file

Object bundle can be installed to Journal in two forms:

  • files from bundle will be unpacked and installed as separate Journal entries, bundle itself will be removed(similar to .xoj)
    final Journal entries can have activity field, so they are regular Journal entries(that imported to Journal(w/o activity field or created by activities with activity field)
    METADATA should not contain [Entry] section
  • bundles will be installed as a composite object i.e. as a directory of packaged to the bundle files that are represented by one Journal entry
    final Journal entry can't have activity field
    METADATA should contain [Entry] section

Any field in METADATA file can have _file suffix, in that case content of this field(substring w/o _file suffix) will be fetched from file inside of the bundle.

[Metadata] section

This section is mandatory. It describes Datastore metadata fields of final entry in Journal. If bundle is composite(section [Entry] presents) this section defines Journal entry to represent composite object, otherwise Journal entry for [Metadata]/entry file.

Field Flags Notes
entry mandatory if bundle is composite, entry defines access point to composite object (e.g. index.html for library bundles); otherwise it defines file which will be installed to Journal
mime_type mandatory define metadata for a file which will be stored in Journal
uid ignored
* optional any system, users predefined and arbitrary Datastore field

METADATA file could have several [Manifest] sections, in that case they should be parted by different suffixes e.g. [Manifest2], [Manifest.additional] etc. Multi-object bundles could be utilized in >0.86 for collections of objects or actions.

[Entry] section

If this section exists bundle will be installed as a composite object i.e. all bundle files will be represented by one Journal entry(could be useful in case of libraries).

Field Flags Notes
exec optional how to activate Journal entry, overrides [Metadata] fields(like activity and mime_type) of [Metadata]/entry file

MANIFEST file

File which contains a new-line-terminated list of file names inside bundle.

Benefit to Sugar

This feature is a first approach to unified format for all types of bundles.

Current implementation is similar to .xoj bundles except that:

  • it uses INI format instead of json(to make it more user-editing friendly)
  • any field's value could fetched from file inside of the bundle
  • supports multi-object bundles

Scope

  • deprecate .xol bundles
  • deprecate .xoj bundles
  • provide unified format for metadata file in .xo bundles which should support
    • activities, former .xo bundles (0.88)
    • libraries, former .xol bundles (0.86)
    • journal entries, former .xoj bundles (0.86)
  • make Browse upload object bundles when the server says so
  • in an ideal implementation, composite feature should come from Datastore, but since DS has been extensively hacked in 0.86-0.88 cycles, for the first time, it could be a part of shell code

How To Test

How to test non-composite objects:

  1. Create a new TurtleArt activity
  2. Upload the new entry to the SL wiki using Browse
  3. Use Browse to download the entry back to Journal
  4. Resume it from Journal

How to test composite object:

  1. Download any .xol bundle
  2. Activate it(it should be opened in Browse)
  3. Upload Journal entry with library to SL wiki using Browse
  4. Download .xo with library and open it

User Experience

We could have HTTP servers(see Features/Server Objects Sharing) that request .xo files, in that case Browse will provide object bundle for chosen(in ObjectChooser) Journal entry otherwise Browse will upload raw Journal entries.

Dependencies

Fructose dependencies.

Contingency Plan

None necessary, revert to previous release behaviour.

Documentation

Release Notes

The Sugar Release Notes inform end-users about what is new in the release. An Example is 0.84/Notes. The release notes also help users know how to deal with platform changes such as ABIs/APIs, configuration or data file formats, or upgrade concerns. If there are any such changes involved in this feature, indicate them here. You can also link to upstream documentation if it satisfies this need. This information forms the basis of the release notes edited by the release team and shipped with the release.

Comments and Discussion