# MDAST Schema ``` https://ns.adobe.com/helix/pipeline/mdast ``` A node in the Markdown AST | Abstract | Extensible | Status | Identifiable | Custom Properties | Additional Properties | Defined In | | ------------------- | ---------- | ------ | ------------ | ----------------- | --------------------- | -------------------------------------- | | Can be instantiated | No | Stable | No | Forbidden | Forbidden | [mdast.schema.json](mdast.schema.json) | ## Schema Hierarchy - MDAST `https://ns.adobe.com/helix/pipeline/mdast` - [Position](position.schema.md) `https://ns.adobe.com/helix/pipeline/position` - [Meta](meta.schema.md) `https://ns.adobe.com/helix/pipeline/meta` # MDAST Properties | Property | Type | Required | Nullable | Defined by | | ------------------------------- | ---------- | -------- | -------- | ------------------- | | [align](#align) | `enum[]` | Optional | No | MDAST (this schema) | | [alt](#alt) | `string` | Optional | Yes | MDAST (this schema) | | [checked](#checked) | `boolean` | Optional | Yes | MDAST (this schema) | | [children](#children) | `array` | Optional | No | MDAST (this schema) | | [data](#data) | `object` | Optional | No | MDAST (this schema) | | [depth](#depth) | `integer` | Optional | No | MDAST (this schema) | | [identifier](#identifier) | `string` | Optional | No | MDAST (this schema) | | [image](#image) | `string` | Optional | Yes | MDAST (this schema) | | [intro](#intro) | `string` | Optional | Yes | MDAST (this schema) | | [label](#label) | `string` | Optional | No | MDAST (this schema) | | [lang](#lang) | `string` | Optional | Yes | MDAST (this schema) | | [meta](#meta) | `object` | Optional | Yes | MDAST (this schema) | | [ordered](#ordered) | `boolean` | Optional | No | MDAST (this schema) | | [payload](#payload) | `object` | Optional | No | MDAST (this schema) | | [position](#position) | Position | Optional | No | MDAST (this schema) | | [referenceType](#referencetype) | `enum` | Optional | No | MDAST (this schema) | | [spread](#spread) | `boolean` | Optional | Yes | MDAST (this schema) | | [start](#start) | `integer` | Optional | Yes | MDAST (this schema) | | [title](#title) | `string` | Optional | Yes | MDAST (this schema) | | [type](#type) | `enum` | Optional | No | MDAST (this schema) | | [types](#types) | `string[]` | Optional | No | MDAST (this schema) | | [url](#url) | `string` | Optional | No | MDAST (this schema) | | [value](#value) | `string` | Optional | No | MDAST (this schema) | ## align For tables, an align field can be present. If present, it must be a list of alignTypes. It represents how cells in columns are aligned. `align` - is optional - type: `enum[]` - defined in this schema ### align Type Array type: `enum[]` All items must be of the type: Unknown type `null,string`. ```json { "description": "For tables, an align field can be present. If present, it must be a list of alignTypes. It represents how cells in columns are aligned.", "type": "array", "items": { "type": ["null", "string"], "enum": ["left", "right", "center", null], "simpletype": "`enum`", "meta:enum": { "left": "", "right": "", "center": "", "null": "" } }, "simpletype": "`enum[]`" } ``` ## alt An alt field should be present. It represents equivalent content for environments that cannot represent the node as intended. `alt` - is optional - type: `string` - defined in this schema ### alt Type `string`, nullable ## checked A checked field can be present. It represents whether the item is done (when true), not done (when false), or indeterminate or not applicable (when null or not present). `checked` - is optional - type: `boolean` - defined in this schema ### checked Type `boolean` , nullable ## children `children` - is optional - type: `array` - defined in this schema ### children Type Array type: `array` All items must be of the type: **One** of the following _conditions_ need to be fulfilled. #### Condition 1 - []() – `https://ns.adobe.com/helix/pipeline/mdast` #### Condition 2 - []() – `https://ns.adobe.com/helix/pipeline/section#/definitions/section` ## data data is guaranteed to never be specified by unist or specifications implementing unist. Free data space. `data` - is optional - type: `object` - defined in this schema ### data Type `object` with following properties: | Property | Type | Required | | -------- | ---- | -------- | ## depth The heading level `depth` - is optional - type: `integer` - defined in this schema ### depth Type `integer` - minimum value: `1` - maximum value: `6` ## identifier For associations, an identifier field must be present. It can match an identifier field on another node. `identifier` - is optional - type: `string` - defined in this schema ### identifier Type `string` ## image Path (can be relative) to the first image in the document `image` - is optional - type: `string` - defined in this schema ### image Type `string`, nullable - format: `uri-reference` – URI Reference (according to [RFC3986](https://tools.ietf.org/html/rfc3986)) ## intro Extracted first paragraph of the document `intro` - is optional - type: `string` - defined in this schema ### intro Type `string`, nullable ## label For associations, a label field can be present. It represents the original value of the normalised identifier field. `label` - is optional - type: `string` - defined in this schema ### label Type `string` ## lang For code, a lang field can be present. It represents the language of computer code being marked up. `lang` - is optional - type: `string` - defined in this schema ### lang Type `string`, nullable ## meta `meta` - is optional - type: `object` - defined in this schema ### meta Type `object`, nullable, with following properties: | Property | Type | Required | | --------- | ------ | -------- | | `class` | string | Optional | | `image` | string | Optional | | `intro` | string | Optional | | `tagname` | string | Optional | | `title` | string | Optional | | `types` | array | Optional | #### class The CSS class to use for the section instead of the default `hlx-section` one `class` - is optional - type: `string` ##### class Type `string` #### image Path (can be relative) to the first image in the document `image` - is optional - type: `string` ##### image Type `string` - format: `uri-reference` – URI Reference (according to [RFC3986](https://tools.ietf.org/html/rfc3986)) #### intro Extracted first paragraph of the document `intro` - is optional - type: `string` ##### intro Type `string` #### tagname The element tag name to use for the section instead of the default `div` one (i.e. `section`, `main`, `aside`) `tagname` - is optional - type: `string` ##### tagname Type `string` #### title Extracted title of the document `title` - is optional - type: `string` ##### title Type `string` #### types The inferred class names for the section `types` - is optional - type: `string[]` ##### types Type Array type: `string[]` All items must be of the type: `string` ## ordered Is the list ordered `ordered` - is optional - type: `boolean` - defined in this schema ### ordered Type `boolean` ## payload The payload of a frontmatter/yaml block `payload` - is optional - type: `object` - defined in this schema ### payload Type `object` with following properties: | Property | Type | Required | | -------- | ---- | -------- | ## position `position` - is optional - type: Position - defined in this schema ### position Type - [Position](position.schema.md) – `https://ns.adobe.com/helix/pipeline/position` ## referenceType Represents the explicitness of a reference. `referenceType` - is optional - type: `enum` - defined in this schema The value of this property **must** be equal to one of the [known values below](#referencetype-known-values). ### referenceType Known Values | Value | Description | | ----------- | ------------------------------------------------------------------- | | `shortcut` | the reference is implicit, its identifier inferred from its content | | `collapsed` | the reference is explicit, its identifier inferred from its content | | `full` | the reference is explicit, its identifier explicitly set | ## spread A spread field can be present. It represents that any of its items is separated by a blank line from its siblings or contains two or more children (when true), or not (when false or not present). `spread` - is optional - type: `boolean` - defined in this schema ### spread Type `boolean` , nullable ## start Starting item of the list `start` - is optional - type: `integer` - defined in this schema ### start Type `integer`, nullable ## title Extracted title of the document `title` - is optional - type: `string` - defined in this schema ### title Type `string`, nullable ## type The node type of the MDAST node `type` - is optional - type: `enum` - defined in this schema The value of this property **must** be equal to one of the [known values below](#type-known-values). ### type Known Values | Value | Description | | -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `root` | The root node, representing a document or section | | `paragraph` | A paragraph. Note: standalone `image` blocks are often wrapped in a `paragraph` | | `text` | Plain text | | `heading` | A heading with heading level | | `thematicBreak` | A section break | | `blockquote` | A blockquote | | `list` | An ordered or unordered list | | `table` | A table | | `tableRow` | A row in a table | | `tableCell` | A cell in a table | | `html` | Raw HTML embedded in Markdown. Disabled by default. | | `code` | A code block | | `yaml` | A metadata block. If the block is not at the top of the document, it will start a new section. | | `definition` | A definition that can be referenced | | `footnoteDefinition` | A footnote | | `emphasis` | emphasis (often in italics) | | `strong` | strong (often in bold type) | | `delete` | deleted content | | `inlineCode` | inline code | | `break` | A line break | | `link` | A hyperlink | | `image` | An image | | `linkReference` | A pointer to a link | | `imageReference` | A pointer to an image | | `footnote` | A footnote | | `footnoteReference` | A reference to a footnote | | `embed` | Content embedded from another page, identified by the `url` attribute. | | `section` | A section within the document. Sections serve as a high-level structure of a single markdown document and can have their own section-specific front matter metadata. | | `listItem` | | ## types The inferred class names for the section `types` - is optional - type: `string[]` - defined in this schema ### types Type Array type: `string[]` All items must be of the type: `string` ## url For resources, an url field must be present. It represents a URL to the referenced resource. `url` - is optional - type: `string` - defined in this schema ### url Type `string` - format: `uri-reference` – URI Reference (according to [RFC3986](https://tools.ietf.org/html/rfc3986)) ## value The string value of the node, if it is a terminal node. `value` - is optional - type: `string` - defined in this schema ### value Type `string`