Hierarchical Tags

Like many other Web 2.0 systems, Piggydb supports tagging to classify knowledge fragments.
While tagging is simply for classifying a piece of information and allowing it to be found again by browsing or searching, in the context of folksonomy, its simplicity (non-hierarchical keywords) enables organizing information by many people collaboratively, known as “collective intelligence”, and connecting like-minded people.
Piggydb is not a social networking application, so it concentrates on the classifying nature of tagging. In terms of classifying, tagging has many advantages over existing systems such as directories/folders and categories. Tagging is generally more flexible and less brain-racking, and is used to resolve the “Bat problem”.
The ‘Bat problem’ was coined by Japanese economist Yukio Noguchi to describe a problem which arises when classifying information and goods. Material things and information can have multiple attributes that are used descriptively depending on the context (Bats have the properties of both birds and beasts – http://mythfolklore.net/aesopica/milowinter/43.htm).
Bat problem: http://data.lullar.com/%E3%81%93%E3%81%86%E3%82%82%E3%82%8A%E5%95%8F%E9%A1%8C
However, tagging also has its own problems. One of them is losing the grasp of the entire set of tags when the number of tags is growing. Piggydb offers hierarchical tagging to tackle this problem.
Hierarchical tagging allows you to classify a tag through other tags, exactly like knowledge fragments, and the classification is transitive; that is, if there is a tag “cat” classified with a tag “animal” and you classify some fragments with “cat”, then those fragment will be classified as an “animal” also. The hierarchical tagging feature allows you to classify fragments more naturally, and drill down a large number of fragments more easily and smoothly.

Special Tags

Special tags are tags that have special effects when they are attached to knowledge fragments. In order to distinguish from other normal tags, the name of the special tags start with '#'. For example, if you attach a #bookmark tag to a fragment, then the fragment will be added to the bookmark list on the sidebar.

#bookmark tag

#bookmark tag provides quick access to knowledge fragments. If a fragment is tagged with #bookmark, it will be shown in the bookmark list on the sidebar.
You can also bookmark a fragment by clicking on the bookmark button on the fragment toolbar.

#pre tag / #code tag → ...

Adding a #pre tag to a text fragment displays the content "as is" and no further formatting will be applied to it (similar to HTML <pre>..</pre> mark-up).
Adding both #pre and #code tags to a text fragment displays the content "as is" with program-code syntax highlighting.
You can optionally specify the programming language in which the code is written with a #lang-<language name> tag, for more detail of language names, see the google-code-prettify document.

#trash tag

If you want to remove fragments that are no longer needed, attach a #trash tag to each of them. Fragments with #trash will be removed from the list/tree views but will not be deleted completely, so you can recover #trash fragments by removing the #trash tags from them.
You can do the same thing by clicking on the trash button on the fragment toolbar.
You can delete #trash-tagged fragments completely on the #trash tag page.

User Management - #user tag → ...

The user management system is built into the piggydb's semantics seamlessly.
Piggydb has only one user ("owner") by default, but you can create other users just by creating fragments titled "username" and tagged with "#user" tag. These fragments are called "User Fragment", which can be created, changed, or deleted only by an owner.
  • The default password is the same as the user name.
    • If you create a fragment titled "marubinotto" and tagged with "#user", you can login with marubinotto/marubinotto.
  • You can manage the users in exactly the same way as fragments, classifying with tags, connecting to other fragments, and so on.

#public tag

If you use Piggydb in private mode (Anonymous Access is off) and want to show some of your knowledge fragments to others without login, you can do this with #public tag. A fragment tagged with #public can be accessed via Document View (/document-view.htm?id=<n>) without login.
A fragment that is tagged with both #public and #home is called "Public Home" and it can be accessed at http://<your-piggydb-root>/public/. It is a good entry point for #public fragments.