Loom Power BI Report Editor — Fabric-parity spec¶

Captured 2026-05-26 by catalog agent a6112853cd6c023e5.

UI components¶

Embedded Report Canvas¶

Live Power BI report rendering within Fabric workspace
Page navigation tabs at canvas bottom
Real-time visualization updates
Interactive visual selection + modification

Visualizations Pane (right side)¶

Visual type gallery: bar / line / pie / card / table / slicer / map / scatter / waterfall / gauge / KPI / decomposition tree / smart narrative / Q&A (20+ types)
Build visual tab — fields in active visual (drag-drop buckets: Axis, Legend, Values, Tooltips, etc.)
Format visual tab — styling options (paint-brush icon)
Analytics tab — trend lines / reference lines / forecast (magnifying glass icon)

Data (Fields) Pane (rightmost or stacked)¶

Semantic model table listing (full)
Expandable tables → columns + measures
Green checkmarks for fields used in active visual
Drag-drop field assignment to visual buckets
Hierarchies with drill-down arrows
Field-type icons (measure / column / hierarchy)

Filters Pane¶

Three-tier hierarchy:
Filters on all pages (report-level)
Filters on this page (page-level)
Filters on this visual (visual-level)
Shaded filter cards indicating active filters
Filter type config (Basic vs Advanced)
Value selection checkboxes
Numerical range sliders (continuous data)

Page tabs at bottom of canvas
New page via Insert tab or + button
Delete via x icon
Drag-drop reordering
Multi-page report support
Drillthrough page configuration

Ribbon Tabs¶

Home: New Report · Save · Undo · Redo · Share
Insert: New Page · Text box · Shape · Image · Q&A · R/Python script
Modeling: Relationships · Manage relationships · New Column · New Measure · Data Category
View: Reading View · Edit View · Focus Mode · Bookmark panes · Selection pane · Navigator pane
Help: Documentation · Support · Feedback

Format Pane (paint-brush)¶

Visual formatting: colors, fonts, axes
Legend configuration
Data label formatting
Background + border styling
Conditional formatting rules
Title + subtitle config
Tooltip customization

What Loom has¶

Plain Cosmos persistence of "report definition" (state.pages, state.visuals)
C-grade verdict — listing works, embed not present

Gaps for parity¶

No embedded Power BI report — Fabric shows the actual rendered report; Loom shows nothing live
No Visualizations pane with 20+ visual types
No Fields pane showing semantic model
No Filters pane with 3-tier hierarchy
No Pages tabs for multi-page reports
No Format pane
No Q&A natural language query (Insert > Q&A)
No Bookmark / Selection / Navigator panes under View

Backend mapping¶

Power BI embed token flow: /api/embedToken for current user → embed via powerbi-client JS SDK
Report definition JSON read/write via PBI REST /reports/{id} (Fabric stores reports as JSON via .pbip format)
Live data queries flow through the embedded report itself (no Loom proxy)

Required Azure resources / tenant settings¶

Power BI Premium / Fabric capacity for embed
"Service principals can use Power BI APIs" tenant setting ON
"Embed content in apps" tenant setting ON
Workspace assigned to the capacity

Estimated effort¶

3-4 sessions. Phase 1: embed the actual PBI report via embed token (1-2 sessions). Phase 2: surface the right-side panes (Visualizations / Fields / Filters / Format) by re-rendering them around the embedded report iframe (the embedded PBI client exposes events for visual selection, etc).

Notes¶

Loom won't recreate the full PBI editor from scratch — that's prohibitive
Loom EMBEDS the PBI editor inside Loom's chrome; users get the full PBI experience without leaving Loom
This is the same pattern Fabric uses (Fabric IS a chrome around the PBI engine)