### Install Dataview Plugin

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/develop-against-dataview

Install the Dataview plugin as a development dependency using npm.

```bash
npm install -D obsidian-dataview

```

--------------------------------

### Custom View Script Example

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Example of a custom view script (`view1.js`) that logs messages and calls a function with input arguments.

```javascript
console.log(`Loading view1`);

function foo(...args) {
  console.log('foo is called with args', ...args);
}
foo(input)
```

--------------------------------

### Function Syntax Example

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Illustrates the basic syntax for calling a Dataview function with parameters.

```dataview
functionname(parameter1, parameter2)
```

--------------------------------

### YAML Frontmatter Example

Source: https://blacksmithgu.github.io/obsidian-dataview

This example shows how to add metadata to a Markdown file using YAML Frontmatter. Fields like 'author', 'published', and 'tags' are defined at the top of the file.

```markdown
---
author: "Edgar Allan Poe"
published: 1845
tags: poems
---

# The Raven

Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—


```

--------------------------------

### Install Specific Dataview Version

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/develop-against-dataview

Install a specific version of the Dataview plugin if the latest version is not desired or available.

```bash
npm install obsidian-dataview@0.5.64

```

--------------------------------

### Task Examples with Different Metadata Annotations

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/metadata-tasks

Illustrates how tasks can be annotated with metadata using both emoji shorthands and inline fields for the same purpose.

```markdown
- [x] Completed last Saturday ✅2021-08-22
- [x] Some Done Task [completion:: 2021-08-22]

```

--------------------------------

### Inline Fields Example

Source: https://blacksmithgu.github.io/obsidian-dataview

This example demonstrates how to add metadata directly within the content of a Markdown file using inline fields with the `[key:: value]` syntax. This method is functionally equivalent to YAML Frontmatter for Dataview indexing.

```markdown
#poems

# The Raven

From [author:: Edgar Allan Poe], written in (published:: 1845)

Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—


```

--------------------------------

### Function Vectorization Example

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Demonstrates how functions can be applied to both single values and lists of values, returning a corresponding single value or list.

```dataview
lower("YES") = "yes"
lower(["YES", "NO"]) = ["yes", "no"]

replace("yes", "e", "a") = "yas"
replace(["yes", "ree"], "e", "a") = ["yas", "raa"]
```

--------------------------------

### FROM Statement Examples

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/data-commands

Select data from different sources like tags, folders, single files, or links. Supports composition with 'and'/'or' and negation with '-'.

```dataview
FROM #tag
```

```dataview
FROM "folder"
```

```dataview
FROM "path/to/file"
```

```dataview
FROM [[note]]
```

```dataview
FROM outgoing([[note]])
```

```dataview
#tag and "folder"
```

```dataview
[[Food]] or [[Exercise]]
```

```dataview
-#tag
```

```dataview
#tag and -"folder"
```

--------------------------------

### Dataview Modulo Operator Example

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Illustrates the use of the modulo operator (`%`) for calculating the remainder of integer division in Dataview.

```dataview
14 % 2 = 0
14 % 3 = 2
```

--------------------------------

### Duration Literals (Minutes)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in minutes, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 m)
```

```dataview
LIST
WHERE duration > dur(3 mins)
```

```dataview
LIST
WHERE duration > dur(1 minute)
```

```dataview
LIST
WHERE duration > dur(3 minutes)
```

--------------------------------

### List Oldest Incomplete Tasks by File

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

This example demonstrates a complex query for tasks, using WHERE to filter for incomplete tasks, SORT to order them by creation date, LIMIT to restrict the count, and GROUP BY to organize by file. A secondary SORT orders the groups by file creation time.

```dataview
TASK
WHERE !completed
SORT created ASC
LIMIT 10
GROUP BY file.link
SORT rows.file.ctime ASC
```

--------------------------------

### Dataview TASK Query Example

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Demonstrates filtering, sorting, and grouping tasks using Dataview's TASK view. Use WHERE clauses for filtering and GROUP BY for organization.

```dataviewjs
TASK WHERE contains(text, "#tag")
WHERE !completed
GROUP BY file.folder
```

--------------------------------

### Dataview typeof() Function Examples

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Demonstrates the usage of the `typeof()` function to determine the data type of various values in Dataview.

```dataview
typeof("text") = "string"
typof(1) = "number"
typof([1, 2, 3]) = "array"
```

--------------------------------

### Duration Literals (Months)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in months, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 mo)
```

```dataview
LIST
WHERE duration > dur(3 months)
```

--------------------------------

### Check if String Starts With Prefix

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

The `startswith` function returns `true` if a string begins with the specified prefix, and `false` otherwise.

```javascript
startswith("yes", "ye") = true
startswith("path/to/something", "path/") = true
startswith("yes", "no") = false
```

--------------------------------

### Dataview Duration Formats

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Examples of different ways to specify duration fields, including various units and abbreviations.

```dataview
Example:: 7 hours
Example:: 16days
Example:: 4min
Example:: 6hr7min
Example:: 9 years, 8 months, 4 days, 16 hours, 2 minutes
Example:: 9 yrs 8 min
```

--------------------------------

### Calling a Custom View from a Document

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Example of how to call a custom view script (`scripts/view1.js`) from an Obsidian document (`projects/customViews.md`) using `await dv.view()`.

```javascript
await dv.view("scripts/view1", { arg1: 'a', arg2: 'b' }) 
```

--------------------------------

### Duration Literals (Seconds)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in seconds, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 s)
```

```dataview
LIST
WHERE duration > dur(3 secs)
```

```dataview
LIST
WHERE duration > dur(1 second)
```

```dataview
LIST
WHERE duration > dur(3 seconds)
```

--------------------------------

### Duration Literals (Days)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in days, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 d)
```

```dataview
LIST
WHERE duration > dur(3 days)
```

--------------------------------

### Duration Literals (Hours)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in hours, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 h)
```

```dataview
LIST
WHERE duration > dur(3 hrs)
```

```dataview
LIST
WHERE duration > dur(1 hour)
```

```dataview
LIST
WHERE duration > dur(3 hours)
```

--------------------------------

### TABLE Query with Fields

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Use a TABLE query to display specific fields like 'started', 'file.folder', and 'file.etags'. This query filters pages tagged with #games.

```dataview
TABLE started, file.folder, file.etags
FROM #games
```

--------------------------------

### Basic Task Query

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

A simple query to list all tasks within the vault. This serves as a starting point for more complex task management queries.

```dataview
TASK
```

--------------------------------

### Get Page Object by Path

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Fetch a specific page object using its path or link with `dv.page()`. Link resolution and extension detection are automatic.

```javascript
dv.page("Index")
```

```javascript
dv.page("books/The Raisin.md")
```

--------------------------------

### Get Page Paths by Tag

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Retrieve only the file paths of pages matching a specific tag using `dv.pagePaths()`.

```javascript
dv.pagePaths("#books")
```

--------------------------------

### Dataview Inline Text Field

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Example of a simple inline text field. For multiline text, use YAML Frontmatter with the pipe operator.

```dataview
Example:: This is some normal text.
```

--------------------------------

### Specific Date Literals

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of using specific date literals for comparisons, including fixed dates and relative dates like today, tomorrow, and start/end of periods.

```dataview
LIST
WHERE date.year = date(2021-11-11)
```

```dataview
LIST
WHERE date.time = date(2021-09-20T20:17)
```

```dataview
LIST
WHERE date.day = date(today)
```

```dataview
LIST
WHERE date.now = date(now)
```

```dataview
LIST
WHERE date.day = date(tomorrow)
```

```dataview
LIST
WHERE date.day = date(yesterday)
```

```dataview
LIST
WHERE date.day = date(sow)
```

```dataview
LIST
WHERE date.day = date(eow)
```

```dataview
LIST
WHERE date.day = date(som)
```

```dataview
LIST
WHERE date.day = date(eom)
```

```dataview
LIST
WHERE date.day = date(soy)
```

```dataview
LIST
WHERE date.day = date(eoy)
```

--------------------------------

### LIST Query with Computed Additional Information

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Outputs a bullet point list including a computed value as additional information, which can combine multiple fields or logic. This example shows file path and creation day.

```dataview
LIST "File Path: " + file.folder + " _(created: " + file.cday + ")_"
FROM "Games"
```

--------------------------------

### LIST WITHOUT ID with Computed Value and Grouping

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Outputs a grouped list with computed values for each group, excluding the file name or group key. This example calculates the number of pages per type.

```dataview
LIST WITHOUT ID length(rows) + " pages of type " + key
GROUP BY type
```

--------------------------------

### New Date Expressions: Start and End of Week

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Introduces new date expressions: `date(sow)` for the start of the week and `date(eow)` for the end of the week.

```dataview
date(sow)
```

```dataview
date(eow)
```

--------------------------------

### Execute Dataview Query and Get Rendered Markdown

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Asynchronously execute a Dataview query using `dv.queryMarkdown` to obtain rendered Markdown output. Returns a result object containing the rendered Markdown or indicating success/failure.

```javascript
await dv.queryMarkdown("LIST FROM #tag") =>
    { successful: true, value: { "- [[Page 1]]\n- [[Page 2]]" } }
```

--------------------------------

### Inline DQL with Functions and Conditionals

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/dql-js-inline

Utilize DQL functions and conditional logic within inline queries for more complex dynamic content. This example shows date differences, task counts, and conditional messages.

```dql
`= this.due - date(today)`
```

```dql
`= [[Computer Science Theory]].due - date(today)`
```

```dql
`= choice(this.steps > 10000, "YES!", "**No**, get moving!")`
```

```dql
`= length(filter(link(dateformat(date(today), "yyyy-MM-dd")).file.tasks, (t) => !t.completed))`
```

```dql
`= choice(date(today).weekday > 5, "Take it easy!", "Time to get work done!")`
```

--------------------------------

### substring(string, start, [end])

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Extracts a portion of a string from a start index to an optional end index. If the end index is omitted, the substring extends to the end of the original string.

```APIDOC
## substring(string, start, [end])

Extracts a portion of a string from a start index to an optional end index. If the end index is omitted, the substring extends to the end of the original string.

### Parameters
- **string** (string) - The string to extract from.
- **start** (number) - The starting index (inclusive).
- **end** (number, optional) - The ending index (exclusive).

### Examples
```
substring("hello", 0, 2) = "he"
substring("hello", 2, 4) = "ll"
substring("hello", 2) = "llo"
substring("hello", 0) = "hello"
```
```

--------------------------------

### List Pages by Tag, Folder, and Link

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

This query demonstrates complex source selection using LIST. It fetches pages tagged with '#assignment' within the '30 School' folder, OR pages in '30 School/32 Homeworks' linked from 'School Dashboard Current To Dos'.

```dql
```dataview
LIST
FROM (#assignment AND "30 School") OR ("30 School/32 Homeworks" AND outgoing([[School Dashboard Current To Dos]]))
```
```

--------------------------------

### Execute Custom JavaScript View (Basic)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Load and execute a custom JavaScript view from a specified path using `await dv.view()`. This is an asynchronous operation.

```javascript
await dv.view("views/custom", { arg1: ..., arg2: ... });
```

--------------------------------

### Get Length of Array or Object

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Returns the number of elements in an array or the number of fields in an object.

```javascript
length([]) = 0
length([1, 2, 3]) = 3
length(object("hello", 1, "goodbye", 2)) = 2
```

--------------------------------

### Duration Literals (Years)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in years, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 yr)
```

```dataview
LIST
WHERE duration > dur(3 years)
```

--------------------------------

### Basic LIST Query

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Outputs a bullet point list of all files in your vault. This is the simplest form of a LIST query.

```dataview
LIST
```

--------------------------------

### List All Tasks

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/examples

List all tasks within the 'dataview' folder, including sub-tasks and completed tasks.

```dataview
TASK FROM "dataview"
```

--------------------------------

### Duration Literals (Weeks)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Examples of defining duration literals in weeks, using various abbreviations and full words.

```dataview
LIST
WHERE duration > dur(1 w)
```

```dataview
LIST
WHERE duration > dur(3 wks)
```

```dataview
LIST
WHERE duration > dur(1 week)
```

```dataview
LIST
WHERE duration > dur(3 weeks)
```

--------------------------------

### Duration Literals (Combinations)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Demonstrates creating duration literals by combining different time units, using spaces or no spaces between units.

```dataview
LIST
WHERE duration > dur(1 s, 2 m, 3 h)
```

```dataview
LIST
WHERE duration > dur(1 s 2 m 3 h)
```

```dataview
LIST
WHERE duration > dur(1s 2m 3h)
```

```dataview
LIST
WHERE duration > dur(1second 2min 3h)
```

--------------------------------

### Table of Pages with Fields and Aggregations

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

Construct a TABLE view showing pages, their 'due' field, tags, and the average of 'working-hours'. This demonstrates selecting specific fields and using aggregation functions.

```dql
```dataview
TABLE due, file.tags AS "tags", average(working-hours)
```
```

--------------------------------

### Table Query with Date and Type Sorting

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

Creates a table displaying file creation time, appointment type, appointment time, and follow-ups. It filters for notes with the 'follow-ups' field and sorts the results by appointment time.

```dataview
TABLE file.ctime, appointment.type, appointment.time, follow-ups
FROM "30 Protocols/32 Management"
WHERE follow-ups
SORT appointment.time
```

--------------------------------

### dv.markdownTaskList(tasks)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Equivalent to `dv.taskList()`, but returns plain Markdown string.

```APIDOC
## `dv.markdownTaskList(tasks)`

### Description
Equivalent to `dv.taskList()`, which renders a task list, but returns plain Markdown.

### Usage
```javascript
const markdown = dv.markdownTaskList(dv.pages("#project").file.tasks);
dv.paragraph(markdown);
```
```

--------------------------------

### Dataview ISO8601 Date Formats

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Examples of various ISO8601 compliant date formats that Dataview automatically recognizes.

```dataview
Example:: 2021-04 
Example:: 2021-04-18
Example:: 2021-04-18T04:19:35.000
Example:: 2021-04-18T04:19:35.000+06:30
```

--------------------------------

### link(path, [display])

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Constructs a link object to a file. An optional display name can be provided.

```APIDOC
## link(path, [display])

### Description
Construct a link object from the given file path or name. If provided with two arguments, the second argument is the display name for the link.

### Parameters
- **path** (string) - The path or name of the file to link to.
- **display** (string, Optional) - The text to display for the link.

### Examples
```apidoc
link("Hello") // => link to page named 'Hello'
link("Hello", "Goodbye") // => link to page named 'Hello', displays as 'Goodbye'
```
```

--------------------------------

### Dataview Number in YAML Frontmatter

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Example of defining a number field within YAML Frontmatter without quotes.

```yaml
---
rating: 8
description: "A nice little horror movie"
---
```

--------------------------------

### Convert Links to Embedded Equivalents

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Shows how to use the `embed()` function to convert links to their embedded equivalents. The optional second argument can be used to control this conversion.

```dataviewql
embed(link)
```

```dataviewql
embed(link, false)
```

--------------------------------

### Render Headers

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Create HTML headers of different levels (1-6) using `dv.header()`.

```javascript
dv.header(1, "Big!");
```

```javascript
dv.header(6, "Tiny");
```

--------------------------------

### Dataview Task Query with Tags

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Example of how to filter tasks based on their associated tags using the `contains()` function in Dataview.

```dataview
TASK WHERE contains(tags, "#tag")
```

--------------------------------

### Dataview Query for Frontmatter

Source: https://blacksmithgu.github.io/obsidian-dataview/data-annotation

Example of a Dataview query that filters notes based on a nested field defined in the YAML Frontmatter.

```dataview
```dataview
LIST
WHERE thoughts.rating = 8
```
```

--------------------------------

### dv.io.load(path, [origin-file])

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Asynchronously loads the content of a file from the given path. Relative paths are resolved relative to the optional origin file. Returns the file content as a string or undefined if the file is not found.

```APIDOC
## ⌛ `dv.io.load(path, [origin-file])`

### Description
Load the contents of the given path (a link or string) asynchronously. Relative paths will be resolved relative to the optional origin file (defaulting to the current file if not provided). Returns the string contents of the file, or `undefined` if the file does not exist.

### Usage Example
```javascript
await dv.io.load("File")
// Output: "# File\nThis is an example file..."
```
```

--------------------------------

### dv.markdownList(values)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Equivalent to `dv.list()`, but returns plain Markdown string.

```APIDOC
## `dv.markdownList(values)`

### Description
Equivalent to `dv.list()`, which renders a list of the given elements, but returns plain Markdown.

### Usage
```javascript
const markdown = dv.markdownList([1, 2, 3]);
dv.paragraph(markdown);
```
```

--------------------------------

### dv.tryQueryMarkdown(source, [file], [settings])

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Executes a Dataview query asynchronously and returns the results as rendered Markdown. Throws a JavaScript exception if the query execution fails.

```APIDOC
## ⌛ `dv.tryQueryMarkdown(source, [file], [settings])`

### Description
Exactly the same as `dv.queryMarkdown()`, but throws an error on parse failure.

### Parameters
* `source` (string): The Dataview query string.
* `file` (string, optional): The file path to resolve the query from (e.g., for `this`). Defaults to the current file.
* `settings` (object, optional): Execution settings for running the query. Advanced use case.

### Usage Example
```javascript
try {
  await dv.tryQueryMarkdown("LIST FROM #tag");
} catch (e) {
  console.error("Markdown query failed:", e);
}
```
```

--------------------------------

### Basic Dataview Query (LIST)

Source: https://blacksmithgu.github.io/obsidian-dataview

A fundamental Dataview Query Language (DQL) query that lists all files in your vault. This is the simplest form of a DQL query.

```dql
```dataview
LIST
```
```

--------------------------------

### Dataview Multiline Text via YAML

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Shows how to define multiline text values using YAML Frontmatter and the pipe operator.

```yaml
---
poem: |
  Because I could not stop for Death,
  He kindly stopped for me;
  The carriage held but just ourselves
  And Immortality.
author: "[[Emily Dickinson]]"
title: "Because I could not stop for Death"
---
```

--------------------------------

### Get Link Type

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Determine the type of link using `meta(link).type`. Possible values are 'file', 'header', or 'block'.

```dataview
meta([[My Project]]).type = "file"
```

```dataview
meta([[My Project#Next Actions]]).type = "header"
```

```dataview
meta([[My Project#^9bcbe8]]).type = "block"
```

--------------------------------

### Get Type of Value

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Returns the data type of any given value as a string. Useful for conditional logic based on data type.

```dataview
typeof(8) => "number"
```

```dataview
typeof("text") => "string"
```

```dataview
typeof([1, 2, 3]) => "array"
```

```dataview
typeof({ a: 1, b: 2 }) => "object"
```

```dataview
typeof(date(2020-01-01)) => "date"
```

```dataview
typeof(dur(8 minutes)) => "duration"
```

--------------------------------

### Calendar View by Creation Date

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

Create a CALENDAR view where each page is marked with a dot on its creation date (file.cday). This helps visualize content distribution over time.

```dql
```dataview
CALENDAR file.cday
```
```

--------------------------------

### elink(url, [display])

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Constructs a link to an external URL. An optional display name can be provided.

```APIDOC
## elink(url, [display])

### Description
Construct a link to an external url (like `www.google.com`). If provided with two arguments, the second argument is the display name for the link.

### Parameters
- **url** (string) - The external URL.
- **display** (string, Optional) - The text to display for the link.

### Examples
```apidoc
elink("www.google.com") // => link element to google.com
elink("www.google.com", "Google") // => link element to google.com, displays as "Google"
```
```

--------------------------------

### Create Empty List

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Creates an empty list. The `array` alias can also be used.

```dataview
list()
```

--------------------------------

### String Functions: startswith, endswith, padleft, padright, string

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Adds new string manipulation functions: `startswith`, `endswith` for checking string prefixes/suffixes, `padleft` and `padright` for padding strings, and `string` for type conversion.

```dataview
startswith(string, prefix)
```

```dataview
endswith(string, suffix)
```

```dataview
padleft(string, length, char)
```

```dataview
padright(string, length, char)
```

```dataview
string(value)
```

--------------------------------

### Calculating Overtime in Dataview

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/expressions

Calculates the overtime duration by subtracting 8 hours from the difference between 'end' and 'start' timestamps. Results are aliased as 'Overtime'.

```dataview
TABLE start, end, (end - start) - dur(8 h) AS "Overtime" 
FROM #work

```

--------------------------------

### LIST Query with Additional Information

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Outputs a bullet point list including an additional piece of information for each file, such as its folder. Only one additional information field can be specified.

```dataview
LIST file.folder
```

--------------------------------

### Inline DQL for Date Calculations

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/dql-js-inline

Use inline DQL to perform calculations and display dynamic text. This example calculates the time remaining until an exam.

```dql
`= date(today)`
```

```dql
`= [[exams]].deadline - date(today)`
```

--------------------------------

### dv.markdownTable(headers, values)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Equivalent to `dv.table()`, but returns plain Markdown string.

```APIDOC
## `dv.markdownTable(headers, values)`

### Description
Equivalent to `dv.table()`, which renders a table with the given list of headers and 2D array of elements, but returns plain Markdown.

### Usage
```javascript
// Render a simple table of book info sorted by rating.
const table = dv.markdownTable(["File", "Genre", "Time Read", "Rating"], dv.pages("#book")
    .sort(b => b.rating)
    .map(b => [b.file.link, b.genre, b["time-read"], b.rating]))

dv.paragraph(table);
```
```

--------------------------------

### Dataview Query for Frontmatter

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/add-metadata

Query notes based on metadata defined in their YAML Frontmatter. This example filters notes where the nested 'thoughts.rating' field is 8.

```dataview
LIST
WHERE thoughts.rating = 8
```

--------------------------------

### Display Files by Modification Time

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/examples

List all files in the 'books' folder, displaying their last modification time ('mtime') in a table, sorted by modification time in descending order.

```dataview
TABLE file.mtime AS "Last Modified"
FROM "books"
SORT file.mtime DESC
```

--------------------------------

### Get Link Subpath

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Extract the subpath of a link using `meta(link).subpath`. This will be the heading text or block ID if applicable, otherwise null.

```dataview
meta([[My Project#Next Actions]]).subpath = "Next Actions"
```

```dataview
meta([[My Project#^9bcbe8]]).subpath = "9bcbe8"
```

```dataview
meta([[My Project]]).subpath = null
```

--------------------------------

### Render Dataview Task List

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Use `dv.taskList()` to render Dataview `Task` objects. By default, tasks are grouped by file. Set the second argument to `false` to render a single unified list.

```javascript
// List all tasks from pages marked '#project'
dv.taskList(dv.pages("#project").file.tasks)
```

```javascript
// List all *uncompleted* tasks from pages marked #project
dv.taskList(dv.pages("#project").file.tasks
    .where(t => !t.completed))
```

```javascript
// List all tasks tagged with '#tag' from pages marked #project
dv.taskList(dv.pages("#project").file.tasks
    .where(t => t.text.includes("#tag")))
```

```javascript
// List all tasks from pages marked '#project', without grouping.
dv.taskList(dv.pages("#project").file.tasks, false)
```

--------------------------------

### Execute Custom JavaScript View with CSS

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Load a custom JavaScript view from a folder containing `view.js` and `view.css`. The CSS file will be automatically included.

```javascript
await dv.view(".views/view1", { arg1: 'a', arg2: 'b' });
```

--------------------------------

### Get Link Path

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Retrieve the file path portion of a link using `meta(link).path`. This works for links to files, headings, and blocks.

```dataview
meta([[My Project]]).path = "My Project"
```

```dataview
meta([[My Project#Next Actions]]).path = "My Project"
```

```dataview
meta([[My Project#^9bcbe8]]).path = "My Project"
```

--------------------------------

### General Literals in Dataview

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Demonstrates various general-purpose literals including numbers, text, links, lists, objects, dates, and durations.

```dataview
LIST
WHERE file.day.year = 2022
```

```dataview
LIST
WHERE contains(file.name, "Math")
```

```dataview
LIST
FROM [[Study MOC]]
```

```dataview
TASK
WHERE !completed AND file.day = date(yesterday)
```

```dataview
LIST
WHERE end - start > dur(2 days)
```

--------------------------------

### TABLE WITHOUT ID Query with Fields

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Use TABLE WITHOUT ID to exclude the default file link column. This example displays 'steamid' and 'file.etags'.

```dataview
TABLE WITHOUT ID
steamid,
file.etags AS "File Tags"
FROM #games
```

--------------------------------

### Create List with Values

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Creates a list containing the specified values. The `array` alias can also be used.

```dataview
list(1, 2, 3)
```

```dataview
array("a", "b", "c")
```

--------------------------------

### Extract a Portion of an Array

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

The `slice` function returns a shallow copy of a portion of an array. It can select elements from a start index to an end index, or count from the end.

```javascript
slice([1, 2, 3, 4, 5], 3) = [4, 5] => All items from given position, 0 as first
slice(["ant", "bison", "camel", "duck", "elephant"], 0, 2) = ["ant", "bison"] => First two items
slice([1, 2, 3, 4, 5], -2) = [4, 5] => counts from the end, last two items
slice(someArray) => a copy of someArray
```

--------------------------------

### object(key1, value1, ...)

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Creates a new object with alternating string keys and values. An empty call creates an empty object.

```APIDOC
## object(key1, value1, ...)

### Description
Creates a new object with the given keys and values. Keys and values should alternate in the call, and keys should always be strings/text.

### Parameters
- **key1** (string) - The first key for the object.
- **value1** (any) - The value associated with the first key.
- **...** (keyN, valueN) - Additional alternating keys and values.

### Examples
```apidoc
object() // => empty object
object("a", 6) // => object which maps "a" to 6
object("a", 4, "c", "yes") // => object which maps a to 4, and c to "yes"
```
```

--------------------------------

### Extract substring in DataviewJS

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

The `substring` function is now available for DataviewJS users to extract portions of strings. It takes the string, a start index, and an optional end index.

```javascript
substring(string, start[, end])
```

--------------------------------

### Custom Table Header with Markdown Link

Source: https://blacksmithgu.github.io/obsidian-dataview/changelog

Demonstrates how to use arbitrary markdown, including links, within Dataview table headers. This allows for more dynamic and informative table column titles.

```dataviewql
TABLE (1 + 2) AS "[[File]]"
```

--------------------------------

### General DQL Query Structure

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

A DQL query follows a general pattern starting with a Query Type, followed by an optional FROM statement, and then zero or more other data commands.

```dql
```dataview
<QUERY-TYPE> <fields>
FROM <source>
<DATA-COMMAND> <expression>
<DATA-COMMAND> <expression>
          ...
```
```

--------------------------------

### Link Literal as Source

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/literals

Utilize a link literal to specify a source file or MOC for your query.

```dataview
LIST
FROM [[Study MOC]]
```

--------------------------------

### Get Link Display Text

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Access the display text of a link using `meta(link).display`. Returns null if the link does not have a defined display text.

```dataview
meta([[2021-11-01|Displayed link text]]).display = "Displayed link text"
```

```dataview
meta([[2021-11-01]]).display = null
```

--------------------------------

### Querying Object Properties

Source: https://blacksmithgu.github.io/obsidian-dataview/annotation/types-of-metadata

Access nested object properties in Dataview queries using dot notation (e.g., `obj.key1`). This example displays object properties in a table.

```dataview
TABLE obj.key1, obj.key2, obj.key3
WHERE file = this.file
```

--------------------------------

### Render Markdown Task List

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Use `dv.markdownTaskList()` to generate a plain Markdown task list string. This is equivalent to `dv.taskList()` but returns Markdown text.

```javascript
const markdown = dv.markdownTaskList(dv.pages("#project").file.tasks);
dv.paragraph(markdown);
```

--------------------------------

### dv.taskList(tasks, groupByFile)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Renders a Dataview list of Task objects. By default, tasks are grouped by their origin file.

```APIDOC
## `dv.taskList(tasks, groupByFile)`

### Description
Render a dataview list of `Task` objects, as obtained by `page.file.tasks`. By default, this view will automatically group the tasks by their origin file. If you provide `false` as a second argument explicitly, it will instead render them as a single unified list.

### Usage
```javascript
// List all tasks from pages marked '#project'
dv.taskList(dv.pages("#project").file.tasks)

// List all *uncompleted* tasks from pages marked #project
dv.taskList(dv.pages("#project").file.tasks
    .where(t => !t.completed))

// List all tasks tagged with '#tag' from pages marked #project
dv.taskList(dv.pages("#project").file.tasks
    .where(t => t.text.includes("#tag")))

// List all tasks from pages marked '#project', without grouping.
dv.taskList(dv.pages("#project").file.tasks, false)
```
```

--------------------------------

### Filter Notes by Date

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/structure

Use the WHERE command to filter notes based on metadata fields. This example selects pages where the 'due' field exists and is before today's date.

```dataview
LIST
WHERE due AND due < date(today)
```

--------------------------------

### Create Link to Page

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Constructs a link object to a Dataview page. An optional display name can be provided.

```dataview
link("Hello") => link to page named 'Hello'
```

```dataview
link("Hello", "Goodbye") => link to page named 'Hello', displays as 'Goodbye'
```

--------------------------------

### Get First Non-Null Value from Array

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Returns the first non-null value encountered in an array. Useful for selecting the first available field value from a list of children.

```javascript
firstvalue([null, 1, 2]) => 1
firstvalue(children.myField) => If children.myField equals [null, null, "myValue", null], it would return "myValue"
```

--------------------------------

### Filter Tasks by Urgency

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Filters tasks where the 'urgent' field is true. This example shows how to query for specific metadata on tasks, including child tasks that might match the criteria.

```dataview
TASK
WHERE urgent
```

--------------------------------

### Render Markdown List

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Use `dv.markdownList()` to generate a plain Markdown list string. This is equivalent to `dv.list()` but returns Markdown text.

```javascript
const markdown = dv.markdownList([1, 2, 3]);
dv.paragraph(markdown);
```

--------------------------------

### WHERE Clause: Filter Incomplete and Old Projects

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/data-commands

Find projects that are not marked as 'completed' and were created more than a month ago, based on creation time (ctime).

```dataview
LIST FROM #projects
WHERE !completed AND file.ctime <= date(today) - dur(1 month)
```

--------------------------------

### LIST WITHOUT ID with Additional Information

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/query-types

Outputs a bullet point list of an additional information field without the file name or group key. This example shows the 'type' field.

```dataview
LIST WITHOUT ID type
```

--------------------------------

### Inline Dataview JS to Display File Modification Time

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/dql-js-inline

Embed a JavaScript expression directly in your text using inline `$=` syntax. This example displays the modification time of the current file.

```javascript
`$= dv.current().file.mtime`
```

--------------------------------

### Query All Pages

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Retrieve all pages in your vault using `dv.pages()` without any source filter.

```javascript
dv.pages()
```

--------------------------------

### Inline DQL to Display Current File Name

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/dql-js-inline

Embed a DQL query directly within your text to display a single value. This example shows how to display the name of the current file.

```dql
`= this.file.name`
```

--------------------------------

### Extract Substring

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Use `substring` to extract a portion of a string. Specify the start index and optionally an end index. If the end index is omitted, the substring extends to the end of the original string.

```javascript
substring("hello", 0, 2) = "he"
substring("hello", 2, 4) = "ll"
substring("hello", 2) = "llo"
substring("hello", 0) = "hello"

```

--------------------------------

### Indexing Through Links

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/expressions

Access properties of linked pages directly within expressions. Use `[[Page Name]].property` to get a property from a specific page, or `Object.propertyName` if the link is stored in a field.

```dataview
[[Assignment Math]].duedate
```

```dataview
Class.timetable
```

--------------------------------

### dv.tryQuery(source, [file, settings])

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Executes a Dataview query asynchronously and returns the results. Throws a JavaScript exception if the query execution fails.

```APIDOC
## ⌛ `dv.tryQuery(source, [file, settings])`

### Description
Exactly the same as `dv.query`, but more convenient in short scripts as execution failures will be raised as JavaScript exceptions instead of a result type.

### Parameters
* `source` (string): The Dataview query string.
* `file` (string, optional): The file path to resolve the query from (e.g., for `this`). Defaults to the current file.
* `settings` (object, optional): Execution settings for running the query. Advanced use case.

### Usage Example
```javascript
try {
  await dv.tryQuery("LIST FROM #tag");
} catch (e) {
  console.error("Query failed:", e);
}
```
```

--------------------------------

### Dataview JavaScript (JS) for Grouped Lists

Source: https://blacksmithgu.github.io/obsidian-dataview/queries/dql-js-inline

Use `dataviewjs` codeblocks for advanced data manipulation and custom views with JavaScript. This example filters pages by tag and rating, then groups and lists them by genre.

```javascript
```dataviewjs
let pages = dv.pages("#books and -#books/finished").where(b => b.rating >= 7);
for (let group of pages.groupBy(b => b.genre)) {
   dv.header(3, group.key);
   dv.list(group.rows.file.name);
}
```
```

--------------------------------

### List Files by Date in Title

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/examples

List files that have a date in their title (format: YYYY-MM-DD), sorted by date in descending order. It filters for files where 'file.day' is present.

```dataview
LIST file.day WHERE file.day
SORT file.day DESC
```

--------------------------------

### Styling Dataview Tables with CSS Snippets

Source: https://blacksmithgu.github.io/obsidian-dataview/resources/faq

Apply custom CSS to Dataview tables by defining CSS classes in your Obsidian settings and referencing them in your CSS snippets. This example targets tables with the class 'myTable'.

```css
.myTable dataview.table {
    background-color: green
}
```

--------------------------------

### dv.view(path, input)

Source: https://blacksmithgu.github.io/obsidian-dataview/api/code-reference

Loads and executes a custom DataviewJS view script from a specified path, passing it input data. This is an asynchronous function.

```APIDOC
## `dv.view(path, input)`

### Description
Complex function which allows for custom views. Will attempt to load a JavaScript file at the given path, passing it `dv` and `input` and allowing it to execute. This allows for you to re-use custom view code across multiple pages. Note that this is an asynchronous function since it involves file I/O - make sure to `await` the result!

### Method
`await dv.view(path, input)`

### Parameters
#### Parameters
- **path** (string) - Required - The path to the custom view script (relative to the vault root).
- **input** (any) - Optional - Data to be passed to the view script.

### Examples
```dataviewjs
// Example with data argument
await dv.view("views/custom", { arg1: ..., arg2: ... });

// Example with custom CSS file in the same folder
// views/custom
//  -> view.js
//  -> view.css
await dv.view("views/custom", { arg1: 'a', arg2: 'b' });
```

### Notes
- View scripts have access to the `dv` object (the API object), and an `input` object which is exactly whatever the second argument of `dv.view()` was.
- `dv.view()` cannot read from directories starting with a dot, like `.views`.
- Directory paths always originate from the vault root.
```

--------------------------------

### Create Empty Object

Source: https://blacksmithgu.github.io/obsidian-dataview/reference/functions

Creates an empty object. Useful for initializing data structures.

```dataview
object()
```