Early Feedback Requested: CAP Excel Library (Not Released Yet)

[Fab2295]

Overview

I’m currently building a new library focused on generating Excel files in a structured, performant, and developer-friendly way. Especially for SAP CAP (Cloud Application Programming Model) projects.

This library is still under development and has not been released yet.
The repository is currently private, and I’m looking for early feedback before making it public.

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What Makes This Different?

Instead of manually defining columns, headers, and mappings, the library is designed to leverage CAP metadata directly.

Core idea:
Use your CDS model as the single source of truth and generate Excel from it.

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Key Features (Already Implemented)

1. CAP Entity → Excel (Core Feature)

sheet.addEntity(Books, {
  rows,
  labels: true,
  i18n: true,
  autoFormat: true
})

Automatically generates:

• Columns from CDS
• Labels from annotations
• Correct data types
• Column order

Supports:

• Arrays
• Objects
• CAP Queries (cds.Query, cds.ql)
• Real runtime data

Extra controls:

sheet.getEntity().setAutoFormat(config)
sheet.getEntity().addRows(rows)

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2. Data Validation

sheet.addValidation('B2:B10', {
  type: 'list',
  values: ['Open', 'Closed', 'Blocked']
})

• List validation
• Numeric validation
• Date validation
• Focus on template generation

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3. Logging Strategy

• Uses cds.log('excel') when in CAP
• Fallback to console.*
• No external dependencies
• No logging in hot paths

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4. Excel Generation

The library already generates:

• Structured tables
• Typed data (dates, numbers, etc.)
• Clean layout ready for real usage

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Real Output (Test)

Below is a real Excel file generated by the library during testing:

Result:

This is not mocked or manually created — it is a direct output from the current implementation.

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Design Principles

• Zero external dependencies
• CAP-first (but not CAP-only)
• Short and predictable API
• Performance-aware
• Safe by default
• Extensible

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What I’m Looking For

• API design feedback
• Missing features
• Naming improvements
• CAP integration validation
• Developer experience

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Important Notes

• Not released yet
• Private repository
• API may change

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If you were to use this in a CAP or Node.js project:

• What would you expect?
• What would be a dealbreaker?
• What would make you adopt it?