Filters and formulas

A view's filters decide which flows it lists. A formula works out a column from the others. They are two different things: a filter is picked, a formula is written. What a view is, and where it lives, is in Organizing flows.

Filters

A filter is a property, an operator and a value — chosen from dropdowns, never typed as code. There is nothing to get syntactically wrong, which is the point: a filter cannot be a syntax error.

Open Filter in the toolbar and each condition reads as a sentence:

Owner        is            ana
Priority     is greater…   5
The file     has tag       smoke

Conditions sit in a group, and the group decides how they combine:

Group	Keeps a flow when
All of the following are true	every condition matches
Any of the following is true	at least one matches
None of the following is true	not one matches

Add filter group nests a group inside a group, so "owner is ana, and either it is a smoke test or its priority is above 5" is built rather than written.

The editor has two sections. This view filters the view you are on; All views filters every view in the context, on top of whatever each one asks for. The count above updates as you build, before you apply anything.

The operators

Which ones a property offers depends on what it holds — a number is never offered starts with.

The property holds	Operators
Text	is, is not, contains, does not contain, starts with, ends with
Number	is, is not, is greater than, is greater than or equal to, is less than, is less than or equal to
Checkbox	is checked, is not checked
Date	is, is before, is on or before, is after, is on or after — against a date, today or now
List	is, is not, has any of, has all of, has none of, contains
The file itself	is in folder, is not in folder, has tag, does not have tag, has property, does not have property

Every type also has is empty and is not empty.

A property a flow does not carry is empty, and empty never satisfies a comparison — so a filter is never broken by a flow nobody has annotated yet. Is in folder matches the folder and everything below it.

Values are suggested from what the folder's flows actually hold, so a tag or an owner is picked from the ones that exist rather than remembered.

In views.yaml

Filters are stored as what they are:

views:
  - type: table
    name: Critical
    filters:
      conjunction: and
      conditions:
        - property: note.priority
          operator: greaterThan
          value: 5
        - property: file
          operator: hasTag
          value: [smoke]
        - conjunction: or
          conditions:
            - property: note.owner
              operator: is
              value: ana
            - property: note.reviewed
              operator: isTrue

A bare property name is frontmatter, so priority and note.priority are the same thing. property: file is the file itself, not a frontmatter key called "file".

Formulas

A formula is an expression — it computes a value, so it needs a language. Four namespaces are available:

Namespace	What it holds
note.<property>	A frontmatter property of the flow
file.<property>	name, basename, path, folder, ext, size, ctime, mtime, tags
flow.<property>	title, description, steps, hasErrors
formula.<name>	Another formula

formulas:
  coverage: 'if(flow.steps > 3, "deep", "shallow")'
  owner: 'default(note.owner, "nobody")'
  age: 'file.mtime.format("YYYY-MM-DD")'

Functions include if(condition, then, else), min(), max(), round(), number(), date(), now() and default(value, fallback); values carry methods such as contains(), startsWith(), isEmpty(), lower(), join() and format().

A formula that is broken (an unknown function, a typo) is reported above the table instead of taking the view down.