dot-canvas-designer

name	dot-canvas-designer
description	Design Dot. Canvas API windowData layouts - JSON element trees, layout, styles, list rendering, conditions, and display formatting.

Dot Canvas Designer

Use this skill when the user wants to design or revise a Dot. Canvas API card, dashboard, status panel, or windowData layout.

Do not use this skill merely to send an existing payload to a device. For device operations, use dot-device-openapi.

Output Boundary

Produce a Canvas payload or a windowData object. Do not handle API keys, device IDs, or device sending here.

When the user asks to design and send a Canvas card:

1. Use this skill to build the Canvas payload.
2. Use dot-device-openapi to send it.

Composition Model

Build windowData as JSON, not JSX, JavaScript, raw HTML, external CSS, or an image.

Root shape:

{
  "default": [
    {
      "type": "div",
      "props": {
        "tw": "flex flex-col flex-1 bg-white text-black",
        "children": "Hello Dot."
      }
    }
  ]
}

Element shape:

• type: div, span, or img
• props: render props
• props.tw: Tailwind-like utility classes
• props.style: explicit inline style object
• props.children: a string, one element object, or an array of element objects

Dynamic values should read Canvas data through simple get expressions such as {{get inputData "title" default="-"}}.

Supported Template Logic

Use stable display-layer helpers only:

• $for / $empty: list structures
• $ifAny / $then / $else: structural conditions
• if / else: short content branches based on whether a value has content
• compare: short text branches
• formatDate: date display
• formatCompactNumber: number display
• get: read JSON paths

Avoid internal cleaning or transformation helpers such as imageSrc, stripHtml, math, or regexMatch in public Canvas payloads. Do data cleanup and heavy computation before building the JSON payload.

Layout Guidance

• Prefer one bounded root container with flex, w-full, h-full, and explicit background/text colors.
• Use min-w-0, min-h-0, fixed heights, overflow-hidden, lineClamp, textOverflow, and whiteSpace when text could overflow.
• The outermost Canvas element usually should not add padding; device layout spacing comes from layoutFull.
• Use layoutFull.tw or layoutFull.style for full-bleed rendering, background, or padding overrides.
• Keep element count and nesting low. Compose clear sections instead of deeply nested decoration.

References

• references/windowdata.md
• references/examples.md