git:20260702.cfc9a75 to git:20260906.9af3950

- description: Create and edit Obsidian Bases (.base files) with views, filters, formulas, and summaries. Use when working with .base files, creating database-like views of notes, or when the user mentions Bases, table views, card views, filters, or formulas in Obsidian.

- # Obsidian Bases Skill

-

- ## Workflow

-

- 1. **Create the file**: Create a `.base` file in the vault with valid YAML content

- 2. **Define scope**: Add `filters` to select which notes appear (by tag, folder, property, or date)

- 3. **Add formulas** (optional): Define computed properties in the `formulas` section

- 4. **Configure views**: Add one or more views (`table`, `cards`, `list`, or `map`) with `order` specifying which properties to display

- 5. **Validate**: Verify the file is valid YAML with no syntax errors. Check that all referenced properties and formulas exist. Common issues: unquoted strings containing special YAML characters, mismatched quotes in formula expressions, referencing `formula.X` without defining `X` in `formulas`

- 6. **Test in Obsidian**: Open the `.base` file in Obsidian to confirm the view renders correctly. If it shows a YAML error, check quoting rules below

-

- ## Schema

-

- Base files use the `.base` extension and contain valid YAML.

-

- ```yaml

- # Global filters apply to ALL views in the base

- filters:

- # Can be a single filter string

- # OR a recursive filter object with exactly ONE key: and, or, or not

- and:

- - 'status == "active"'

- - not:

- - 'file.hasTag("archived")'

-

- # Define formula properties that can be used across all views

- formulas:

- formula_name: 'expression'

-

- # Configure display names and settings for properties

- properties:

- property_name:

- displayName: "Display Name"

- formula.formula_name:

- displayName: "Formula Display Name"

- file.ext:

- displayName: "Extension"

-

- # Define custom summary formulas

- summaries:

- custom_summary_name: 'values.mean().round(3)'

-

- # Define one or more views

- views:

- - type: table | cards | list | map

- name: "View Name"

- limit: 10 # Optional: limit results

- groupBy: # Optional: group results

- property: property_name

- direction: ASC | DESC

- filters: # View-specific filters follow the same rules

- and:

- - 'status == "active"'

- order: # Properties to display in order

- - file.name

- - property_name

- - formula.formula_name

- summaries: # Map properties to summary formulas

- property_name: Average

- ```

-

- ## Filter Syntax

-

- Filters narrow down results. They can be applied globally or per-view.

-

- ### Filter Structure

-

- ```yaml

- # Single filter

- filters: 'status == "done"'

-

- # AND - all conditions must be true

- filters:

- and:

- - 'status == "done"'

- - 'priority > 3'

-

- # OR - any condition can be true

- filters:

- or:

- - 'file.hasTag("book")'

- - 'file.hasTag("article")'

-

- # NOT - exclude matching items

- filters:

- not:

- - 'file.hasTag("archived")'

-

- # Nested filters

- filters:

- or:

- - file.hasTag("tag")

- - and:

- - file.hasTag("book")

- - file.hasLink("Textbook")

- - not:

- - file.hasTag("book")

- - file.inFolder("Required Reading")

- ```

-

- ### Filter Operators

-

- | Operator | Description |

- |----------|-------------|

- | `==` | equals |

- | `!=` | not equal |

- | `>` | greater than |

- | `<` | less than |

- | `>=` | greater than or equal |

- | `<=` | less than or equal |

- | `&&` | logical and |

- | `\|\|` | logical or |

- | <code>!</code> | logical not |

-

- ## Properties

-

- ### Three Types of Properties

-

- 1. **Note properties** - From frontmatter: `note.author` or just `author`

- 2. **File properties** - File metadata: `file.name`, `file.mtime`, etc.

- 3. **Formula properties** - Computed values: `formula.my_formula`

-

- ### File Properties Reference

-

- | Property | Type | Description |

- |----------|------|-------------|

- | `file.name` | String | File name |

- | `file.basename` | String | File name without extension |

- | `file.path` | String | Full path to file |

- | `file.folder` | String | Parent folder path |

- | `file.ext` | String | File extension |

- | `file.size` | Number | File size in bytes |

- | `file.ctime` | Date | Created time |

- | `file.mtime` | Date | Modified time |

- | `file.tags` | List | All tags in file |

- | `file.links` | List | Internal links in file |

- | `file.backlinks` | List | Files linking to this file |

- | `file.embeds` | List | Embeds in the note |

- | `file.properties` | Object | All frontmatter properties |

-

- ### The `this` Keyword

-

- - In main content area: refers to the base file itself

- - When embedded: refers to the embedding file

- - In sidebar: refers to the active file in main content

-

- ## Formula Syntax

-

- Formulas compute values from properties. Defined in the `formulas` section.

-

- ```yaml

- formulas:

- # Simple arithmetic

- total: "price * quantity"

-

- # Conditional logic

- status_icon: 'if(done, "✅", "⏳")'

-

- # String formatting

- formatted_price: 'if(price, price.toFixed(2) + " dollars")'

-

- # Date formatting

- created: 'file.ctime.format("YYYY-MM-DD")'

-

- # Calculate days since created (use .days for Duration)

- days_old: '(now() - file.ctime).days'

-

- # Calculate days until due date

- days_until_due: 'if(due_date, (date(due_date) - today()).days, "")'

- ```

-

- ## Key Functions

-

- Most commonly used functions. For the complete reference of all types (Date, String, Number, List, File, Link, Object, RegExp), see [FUNCTIONS_REFERENCE.md](references/FUNCTIONS_REFERENCE.md).

-

- | Function | Signature | Description |

- |----------|-----------|-------------|

- | `date()` | `date(string): date` | Parse string to date (`YYYY-MM-DD HH:mm:ss`) |

- | `now()` | `now(): date` | Current date and time |

- | `today()` | `today(): date` | Current date (time = 00:00:00) |

- | `if()` | `if(condition, trueResult, falseResult?)` | Conditional |

- | `duration()` | `duration(string): duration` | Parse duration string |

- | `file()` | `file(path): file` | Get file object |

- | `link()` | `link(path, display?): Link` | Create a link |

-

- ### Duration Type

-

- When subtracting two dates, the result is a **Duration** type (not a number).

-

- **Duration Fields:** `duration.days`, `duration.hours`, `duration.minutes`, `duration.seconds`, `duration.milliseconds`

-

- **IMPORTANT:** Duration does NOT support `.round()`, `.floor()`, `.ceil()` directly. Access a numeric field first (like `.days`), then apply number functions.

-

- ```yaml

- # CORRECT: Calculate days between dates

- "(date(due_date) - today()).days" # Returns number of days

- "(now() - file.ctime).days" # Days since created

- "(date(due_date) - today()).days.round(0)" # Rounded days

-

- # WRONG - will cause error:

- # "((date(due) - today()) / 86400000).round(0)" # Duration doesn't support division then round

- ```

-

- ### Date Arithmetic

-

- ```yaml

- # Duration units: y/year/years, M/month/months, d/day/days,

- # w/week/weeks, h/hour/hours, m/minute/minutes, s/second/seconds

- "now() + \"1 day\"" # Tomorrow

- "today() + \"7d\"" # A week from today

- "now() - file.ctime" # Returns Duration

- "(now() - file.ctime).days" # Get days as number

- ```

-

- ## View Types

-

- ### Table View

-

- ```yaml

- views:

- - type: table

- name: "My Table"

- order:

- - file.name

- - status

- - due_date

- summaries:

- price: Sum

- count: Average

- ```

-

- ### Cards View

-

- ```yaml

- views:

- - type: cards

- name: "Gallery"

- order:

- - file.name

- - cover_image

- - description

- ```

-

- ### List View

-

- ```yaml

- views:

- - type: list

- name: "Simple List"

- order:

- - file.name

- - status

- ```

-

- ### Map View

-

- Requires latitude/longitude properties and the Maps community plugin.

-

- ```yaml

- views:

- - type: map

- name: "Locations"

- # Map-specific settings for lat/lng properties

- ```

-

- ## Default Summary Formulas

-

- | Name | Input Type | Description |

- |------|------------|-------------|

- | `Average` | Number | Mathematical mean |

- | `Min` | Number | Smallest number |

- | `Max` | Number | Largest number |

- | `Sum` | Number | Sum of all numbers |

- | `Range` | Number | Max - Min |

- | `Median` | Number | Mathematical median |

- | `Stddev` | Number | Standard deviation |

- | `Earliest` | Date | Earliest date |

- | `Latest` | Date | Latest date |

- | `Range` | Date | Latest - Earliest |

- | `Checked` | Boolean | Count of true values |

- | `Unchecked` | Boolean | Count of false values |

- | `Empty` | Any | Count of empty values |

- | `Filled` | Any | Count of non-empty values |

- | `Unique` | Any | Count of unique values |

-

- ## Complete Examples

-

- ### Task Tracker Base

-

- ```yaml

- filters:

- and:

- - file.hasTag("task")

- - 'file.ext == "md"'

-

- formulas:

- days_until_due: 'if(due, (date(due) - today()).days, "")'

- is_overdue: 'if(due, date(due) < today() && status != "done", false)'

- priority_label: 'if(priority == 1, "🔴 High", if(priority == 2, "🟡 Medium", "🟢 Low"))'

-

- properties:

- status:

- displayName: Status

- formula.days_until_due:

- displayName: "Days Until Due"

- formula.priority_label:

- displayName: Priority

-

- views:

- - type: table

- name: "Active Tasks"

- filters:

- and:

- - 'status != "done"'

- order:

- - file.name

- - status

- - formula.priority_label

- - due

- - formula.days_until_due

- groupBy:

- property: status

- direction: ASC

- summaries:

- formula.days_until_due: Average

-

- - type: table

- name: "Completed"

- filters:

- and:

- - 'status == "done"'

- order:

- - file.name

- - completed_date

- ```

-

- ### Reading List Base

-

- ```yaml

- filters:

- or:

- - file.hasTag("book")

- - file.hasTag("article")

-

- formulas:

- reading_time: 'if(pages, (pages * 2).toString() + " min", "")'

- status_icon: 'if(status == "reading", "📖", if(status == "done", "✅", "📚"))'

- year_read: 'if(finished_date, date(finished_date).year, "")'

-

- properties:

- author:

- displayName: Author

- formula.status_icon:

- displayName: ""

- formula.reading_time:

- displayName: "Est. Time"

-

- views:

- - type: cards

- name: "Library"

- order:

- - cover

- - file.name

- - author

- - formula.status_icon

- filters:

- not:

- - 'status == "dropped"'

-

- - type: table

- name: "Reading List"

- filters:

- and:

- - 'status == "to-read"'

- order:

- - file.name

- - author

- - pages

- - formula.reading_time

- ```

-

- ### Daily Notes Index

-

- ```yaml

- filters:

- and:

- - file.inFolder("Daily Notes")

- - '/^\d{4}-\d{2}-\d{2}$/.matches(file.basename)'

-

- formulas:

- word_estimate: '(file.size / 5).round(0)'

- day_of_week: 'date(file.basename).format("dddd")'

-

- properties:

- formula.day_of_week:

- displayName: "Day"

- formula.word_estimate:

- displayName: "~Words"

-

- views:

- - type: table

- name: "Recent Notes"

- limit: 30

- order:

- - file.name

- - formula.day_of_week

- - formula.word_estimate

- - file.mtime

- ```

-

- ## Embedding Bases

-

- Embed in Markdown files:

-

- ```markdown

- ![[MyBase.base]]

-

- <!-- Specific view -->

- ![[MyBase.base#View Name]]

- ```

-

- ## YAML Quoting Rules

-

- - Use single quotes for formulas containing double quotes: `'if(done, "Yes", "No")'`

- - Use double quotes for simple strings: `"My View Name"`

- - Escape nested quotes properly in complex expressions

-

- ## Troubleshooting

-

- ### YAML Syntax Errors

-

- **Unquoted special characters**: Strings containing `:`, `{`, `}`, `[`, `]`, `,`, `&`, `*`, `#`, `?`, `|`, `-`, `<`, `>`, `=`, `!`, `%`, `@`, `` ` `` must be quoted.

-

- ```yaml

- # WRONG - colon in unquoted string

- displayName: Status: Active

-

- # CORRECT

- displayName: "Status: Active"

- ```

-

- **Mismatched quotes in formulas**: When a formula contains double quotes, wrap the entire formula in single quotes.

-

- ```yaml

- # WRONG - double quotes inside double quotes

- formulas:

- label: "if(done, "Yes", "No")"

-

- # CORRECT - single quotes wrapping double quotes

- formulas:

- label: 'if(done, "Yes", "No")'

- ```

-

- ### Common Formula Errors

-

- **Duration math without field access**: Subtracting dates returns a Duration, not a number. Always access `.days`, `.hours`, etc.

-

- ```yaml

- # WRONG - Duration is not a number

- "(now() - file.ctime).round(0)"

-

- # CORRECT - access .days first, then round

- "(now() - file.ctime).days.round(0)"

- ```

-

- **Missing null checks**: Properties may not exist on all notes. Use `if()` to guard.

-

- ```yaml

- # WRONG - crashes if due_date is empty

- "(date(due_date) - today()).days"

-

- # CORRECT - guard with if()

- 'if(due_date, (date(due_date) - today()).days, "")'

- ```

-

- **Referencing undefined formulas**: Ensure every `formula.X` in `order` or `properties` has a matching entry in `formulas`.

-

- ```yaml

- # This will fail silently if 'total' is not defined in formulas

- order:

- - formula.total

-

- # Fix: define it

- formulas:

- total: "price * quantity"

- ```

- ## References

- - [Bases Syntax](https://help.obsidian.md/bases/syntax)

- - [Functions](https://help.obsidian.md/bases/functions)

- - [Views](https://help.obsidian.md/bases/views)

- - [Formulas](https://help.obsidian.md/formulas)

- - [Complete Functions Reference](references/FUNCTIONS_REFERENCE.md)