UI.CodeBlock
luastra/uiUI.CodeBlock(input: Input): Node
Renders multiline literal source in a scrollable, selectable code region without interpreting markup. It preserves line breaks and supports long examples within bounded page width.
Mental model
This is a declarative node: app.render describes it again from current state, while the host matches its stable id to the existing view.
Before you use it
Add luastra/ui to this module's dependencies in luastra.json, then import it with require("luastra/ui"). The project must declare the ui.render capability. app.render must return one UI.Screen root; place this node inside that tree rather than invoking it for a hidden side effect.
How it fits
The constructor validates its fields immediately and returns a UI.Node. After app.render returns, the host reconciles that node by stable id with the current semantic DOM-based interface. Current desktop and mobile hosts package the same web artifact; native adapters are used at capability boundaries.
When to use it
Use UI.CodeBlock for complete snippets, terminal sessions, JSON, or other preformatted material. Keep prose and very short identifiers in UI.Text or UI.Code.
Shared parameter groups
Parameters
| Parameter | Type / values | Description |
|---|---|---|
| id | lowercase path, required | Unique ID. |
| code | string ≤ 4096 bytes, required | Multiline source text rendered without interpretation. |
| language | safe language name? | Optional source-language label. |
| textStyle | UI.TextStyle? | Local packaged font and bounded size, weight, lineHeight and fallback. Requires the 0.3 source SDK; omitted fields retain defaults. |
| gap | none | xs | sm | md | lg | xl | Space between children. Group: Layout and surfaces. |
| padding | none | xs | sm | md | lg | xl | responsive | All-side inner spacing; responsive is supported only by padding. Group: Layout and surfaces. |
| margin | none | xs | sm | md | lg | xl | All-side outer spacing. Group: Layout and surfaces. |
| paddingX / paddingY | none | xs | sm | md | lg | xl | Axis-specific inner spacing. Group: Layout and surfaces. |
| paddingTop / paddingBottom / paddingStart / paddingEnd | none | xs | sm | md | lg | xl | Logical side-specific inner spacing. Group: Layout and surfaces. |
| marginX / marginY | none | xs | sm | md | lg | xl | Axis-specific outer spacing. Group: Layout and surfaces. |
| marginTop / marginBottom / marginStart / marginEnd | none | xs | sm | md | lg | xl | Logical side-specific outer spacing. Group: Layout and surfaces. |
| surface | plain | card | elevated | accent | Background, border, and elevation. Group: Layout and surfaces. |
| width | full | content | wide | Available width, 720 px maximum, or 1180 px maximum. Group: Layout and surfaces. |
| align | start | center | end | stretch | between | Cross-axis alignment. Group: Layout and surfaces. |
| justify | start | center | end | between | Main-axis alignment. Group: Layout and surfaces. |
| flow | wrap | nowrap | Flex wrapping. Group: Layout and surfaces. |
| responsive | boolean | Narrow-screen adaptation. Group: Layout and surfaces. |
| className | safe string ≤ 256 bytes | Additional admitted class tokens. Group: Layout and surfaces. |
| role | alert | group | status | Supported ARIA role. Group: State and semantics. |
| label | string | Accessible name. Group: State and semantics. |
| hidden | boolean | Visibility state. Group: State and semantics. |
| textColor | token | #RRGGBB | Local or inherited foreground. Group: Text and local colors. |
| backgroundColor | token | #RRGGBB | Component-box background. Group: Text and local colors. |
| Color tokens | accent | danger | muted | surface | success | text | transparent | warning | Current Screen theme colors. Group: Text and local colors. |
Children and layout
This component does not accept arbitrary child nodes; named parameters provide its content.
Accessibility and keyboard
A stable id, logical render-tree order, and visible labels preserve predictable keyboard and screen-reader navigation.
Common mistakes
- Using a duplicate id or an uppercase path segment.
- Passing a shared-group parameter that is not listed on this component page.
Returns
Node — a validated declarative UI node that becomes part of the next host-neutral render tree.
What happens next
A validated declarative node appears after it is returned as part of the current render tree.
Failures and fixes
Invalid fields, duplicate IDs, unsupported child combinations, or a missing ui.render capability fail during check, render-tree validation, or host startup.
Availability
Source API in 0.5.0-alpha; the public installer targets 0.5.0-alpha. Verify host-specific behavior against the selected SDK.
Focused example
UI.CodeBlock { id = "docs/example", code = "local UI = require(\"luastra/ui\")", language = "Luau" }