Portable Text Serialization

Portable Text Serialization

Render Portable Text content across frameworks using the @portabletext/* library family. Each library follows the same component-mapping pattern: you provide a components object that maps PT node types to framework-specific renderers.

Portable Text Structure (Quick Reference)

PT is an array of blocks. Each block has _type, optional style, children (spans), markDefs, listItem, and level.

Root array
├── block (_type: "block")
│   ├── style: "normal" | "h1" | "h2" | "blockquote" | ...
│   ├── children: [span, span, ...]
│   │   └── span: { _type: "span", text: "...", marks: ["strong", "<markDefKey>"] }
│   ├── markDefs: [{ _key, _type: "link", href: "..." }, ...]
│   ├── listItem: "bullet" | "number" (optional)
│   └── level: 1, 2, 3... (optional, for nested lists)
├── custom block (_type: "image" | "code" | any custom type)
└── ...more blocks

Marks come in two forms:

• Decorators: string values in marks[] like "strong", "em", "underline", "code"

• Annotations: keys in marks[] referencing entries in markDefs[] (e.g., links, internal references)

Component Mapping Pattern (All Frameworks)

Every @portabletext/* library accepts a components object with these keys:

Framework-Specific Rules

Read the rule file matching your framework:

• React / Next.js: rules/react.md — @portabletext/react or next-sanity

• Svelte / SvelteKit: rules/svelte.md — @portabletext/svelte

• Vue / Nuxt: rules/vue.md — @portabletext/vue

• Astro: rules/astro.md — astro-portabletext

• HTML (server-side): rules/html.md — @portabletext/to-html

• Markdown: rules/markdown.md — @portabletext/markdown

• Plain text extraction: rules/plain-text.md — @portabletext/toolkit

Additional Community Serializers

These are listed on portabletext.org but don't have dedicated rule files:

Common Patterns (All Frameworks)

Custom Types Need Explicit Components

PT renderers only handle standard blocks by default. Custom types (image, code, callToAction, etc.) require explicit component mappings — they won't render otherwise.

Keep Components Object Stable

In React/Vue, define components outside the render function or memoize it. Recreating on every render causes unnecessary re-renders.

Handle Missing Components Gracefully

All libraries accept onMissingComponent to control behavior when encountering unknown types:

• false — suppress warnings

• Custom function — log or report

Querying PT with GROQ

Always expand references inside custom blocks:

body[]{
  ...,
  _type == "image" => {
    ...,
    asset->
  },
  markDefs[]{
    ...,
    _type == "internalLink" => {
      ...,
      "slug": @.reference->slug.current
    }
  }
}