silverbullet/website/Objects.md

SilverBullet automatically builds and maintains an index of objects extracted from all markdown pages in your space. It subsequently allows you to Live Queries this database in (potentially) useful ways.

By design, the truth remains in the markdown: all data indexed as objects will have a representation in markdown text as well. This index can be flushed at any time and be rebuilt from its source markdown files kept in your space (and you can do so on demand if you like using the {[Space: Reindex]} command).

Object representation

Every object has a set of Attributes, some predefined, but you can add any additional custom attributes that you like.

The following attributes are predefined, and you can expect all objects to have them:

• ref: a globally unique identifier, often represented as a pointer to the place (page, position) in your space where the object is defined. For instance, a page object will use the page name as its ref attribute, and a task will use page@pos (where pos is the location the task appears in page).
• tag: the main type, or “tag” of the page, usually a built-in type of the object (see below).

In addition, many objects will also contain:

• tags: an optional set of additional, explicitly assigned tags.
• itags: a set of implicit or inherited tags: including the object’s tag, tags as well as any tags assigned to its containing page. This is useful to answer queries like, “give me all tasks on pages where that page is tagged with person“, which would be expressed as task where itags = "person" (although technically that would also match any tags that have the #person explicitly assigned).

Beside these, any number of additional tag-specific and custom Attributes can be defined (see below).

Tags

$tags Every object has a main tag, which signifies the type of object being described. In addition, any number of additional tags can be assigned as well via the tags attribute. You can use either the main tag or any of the tags as query sources in Live Queries — examples below.

Here are the currently built-in tags:

page

$page Every page in your space is available via the page tag. You can attach additional tags to a page, by either specifying them in the tags attribute Frontmatter, or by putting additional Tags in a stand alone paragraph with no other (textual) content in them, e.g.:

#example-tag #another-tag

In addition to ref and tags, the page tag defines a bunch of additional attributes as can be seen in this example query:

page where name = "{{@page.name}}"

Note that you can also query this page using the example-tag directly:

example-tag

task

$task Every task in your space is tagged with the task tag by default. You tag it with additional tags by using Tags in the task name, e.g.

• My task #upnext

And can then be queried via either task or upnext.

The following query shows all attributes available for tasks:

upnext

Although you may want to render it using a template such as Library/Core/Query/Task instead:

upnext render [[Library/Core/Query/Task]]

taskstate

Plugs/Tasks support the default x and states (done and not done), but custom states as well. Custom states used across your space are kept in taskstate:

• [NOT STARTED] Task 1
• [IN PROGRESS] Task 2

And can be queried as follows:

taskstate where page = "{{@page.name}}"

template

$template Indexes all pages tagged with #template. See Templates for more information on templates.

template select name limit 5

item

$item List items (both bullet point and numbered items) are indexed with the item tag, and additional tags can be added using Tags.

Here is an example of a #quote item using a custom Attributes:

• “If you don’t know where you’re going you may not get there.” [by: Yogi Berra] #quote

And then queried via the #quote tag:

quote where page = "{{@page.name}}" and tag = "item" select name, by

paragraph

$paragraph Top-level paragraphs (that is: paragraphs not embedded in a list) are indexed using the paragraph tag, any additional tags can be added using Tags.

A paragraph with a #paragraph-tag.

paragraph-tag

data

$data You can also embed arbitrary YAML data blocks in pages via fenced code blocks and use a tag as a coding language, e.g.

name: Pete
age: 55

Which then becomes queriable via the person tag:

person 

link

$link All page links are tagged with link. You cannot attach additional tags to links. The main two attributes of a link are:

• toPage the page the link is linking to
• page the page the link appears on

In addition, the snippet attribute attempts to capture a little bit of context on where the link appears.

Note: this is the data source used for the {[Mentions: Toggle]} feature as well page {[Page: Rename]}.

Here is a query that shows all links that appear in this particular page:

link where page = "{{@page.name}}"

anchor

$anchor

Anchors use the $myanchor notation to allow deeplinking into a page and are also indexed and queryable. It is not possible to attach additional tags to an anchor.

Here is an example query:

anchor where page = "{{@page.name}}"

tag

$tag The ultimate meta tag is tag itself, which indexes for all tags used, in which page they appear and what their “parent tag” is (the context of the tag: either page, item or task).

Here are the tags used/defined in this page:

tag where page = "{{@page.name}}" select name, parent

attribute

$attribute This is another meta tag, which is used to index all Attributes used in your space. This is used by e.g. attribute completion in various contexts. You likely don’t need to use this tag directly, but it’s there.

attribute where page = "{{@page.name}}" limit 1