Mockup Viewer

A design-time tool for plugin authors. Drop a .html file into your vault and Mockup Viewer renders it inside an isolated iframe with Obsidian's app.css, the active theme, and your plugin CSS all injected — so it looks like the real thing without the build / reload loop.

Why

Iterating on Obsidian plugin UI is painful:

• Want to try a different modal layout? Write TS, build, reload the plugin, open the modal, see the colour is wrong, change, reload again.
• Plain HTML in Reading mode misses Obsidian's CSS variables, font stack, and host-class selectors. It never looks like the real plugin.
• Want to test mobile UI? Toggling is-phone on Obsidian itself breaks the whole app.
• Got an HTML mockup from a designer or AI? You need to eyeball it side-by-side with your real plugin styles, without running the full plugin.

Mockup Viewer solves this:

• Save HTML into Mockup/foo.html — the preview appears instantly.
• The iframe boundary keeps is-phone / is-keyboard-open / your host classes from leaking onto Obsidian's own chrome.
• Obsidian's app.css + your plugin's styles.css are both injected, so visuals are ~1:1 with the real plugin.
• Edits hot-reload (200 ms debounce). Theme switches re-render too.

Trust model. Mockup Viewer executes whatever <script> you put in a mockup. Only open mockups you trust.

Installation

Community plugins

Mockup Viewer is not yet listed in Obsidian's community plugins. Use BRAT or manual install below.

BRAT (beta)

BRAT is a community plugin that installs beta plugins directly from GitHub and keeps them updated.

1. Install the BRAT plugin from Settings → Community plugins → Browse and enable it
2. Run BRAT: Add a beta plugin for testing from the Command Palette
3. Enter the repository: twrusstw/mockup-viewer
4. Enable Mockup Viewer in Settings → Community plugins

Manual

1. Download main.js, manifest.json, styles.css from the latest release
2. Copy them to <vault>/.obsidian/plugins/mockup-viewer/
3. Enable the plugin in Settings → Community plugins

Desktop only (isDesktopOnly: true).

Getting started

1. Open the panel

Command palette → Mockup Viewer: Open panel.

The first run shows an empty state with the inspector panel auto-opened on the right.

2. Add a stylesheet source

Click Add source. Three kinds:

Multiple sources allowed. Order matters — later sources override earlier ones via cascade.

3. Create a mockup

Create the folder Mockup/ in your vault (configurable in the panel) and drop .html files into it. Minimal example:

<div class="my-card">
  <h2>Hello mockup</h2>
  <p>This text picks up your plugin's .my-card styles.</p>
</div>

Save the file — it shows up in the panel's File dropdown. Select it and the preview renders.

4. Iterate

Edit either the HTML or the source stylesheet — the preview re-renders within 200 ms. No plugin reload needed.

Mockup directives

A .html file can start with a contiguous block of HTML comments to control viewport, shell scaffold (as: modal / settings / etc.), host class, and per-file style sources:

<!-- as: settings -->
<!-- host: my-plugin-settings -->
<!-- viewport: mobile -->
<div class="setting-item">…</div>

Full reference (all directives, shell presets, viewport sizes) → docs/directives.md.

Charts

chart.js + chartjs-plugin-datalabels are bundled into the iframe — wire a canvas with data-chart-config='{...}' or use inline <script>. Details → docs/charts.md.

The panel

Top to bottom:

• File — .html file dropdown + Reload button to rescan the folder
• View source / Back to preview — toggle source view (the mockup HTML + every resolved source side by side)
• Viewport — Desktop / Tablet / Mobile segment
• Body classes — chips for extra classes on iframe body. Type and press Enter; click × to remove
• Stylesheet sources — global sources used when a mockup doesn't have its own styles: directive
• Workspace folder — vault folder scanned for .html files (default Mockup)
• Trust reminder pinned to the bottom

Click » to collapse the panel. A small « appears in the host so you can bring it back.

Settings tab

One toggle:

• Inject Obsidian app.css into iframe (default on)

Turn this off if a future Obsidian version changes its stylesheet loading mechanism and the mockup breaks. With the toggle off, only your configured sources are injected.

License

MIT