Skip to content

csv-header-detection.md

Latest commit

 

History

History
100 lines (74 loc) · 3.21 KB

csv-header-detection.md

File metadata and controls

100 lines (74 loc) · 3.21 KB

CSV Header Row Detection

Overview

Automatic detection of header rows in CSV/TSV files with heuristic-based analysis and manual override capability. Headers are styled distinctly and rendered with proper column alignment.

Key Files

  • src/markdown/csv_viewer.rs - Header detection logic, table rendering, state management
  • src/app.rs - Status bar header toggle UI

Implementation Details

Header Detection Heuristics

The detect_header_row() function uses multi-factor scoring to determine if the first row is likely a header:

Heuristic Points Description
No numeric values +30 Headers typically don't contain numbers
Mostly text +15 First row has few numeric values (<30%)
Data is more numeric +25 Data rows have more numbers than first row
Common keywords +10 each (max 30) Detects: id, name, date, email, price, etc.
Unique values +10 All values in first row are distinct

Score threshold: >33 points = treat as header row.

Numeric Value Detection

The is_numeric_value() helper handles various formats:

  • Integers: 123, -456
  • Floats: 123.45, -0.5
  • Currency: $100, €50.00, £25, ¥1000
  • Percentages: 50%
  • Thousands: 1,234, 1,234.56

State Management

pub struct CsvViewerState {
    // ... existing fields
    
    /// Auto-detected header status (None = not yet detected)
    detected_has_header: Option<bool>,
    /// Manual override for header row (None = use auto-detected)
    header_override: Option<bool>,
}

Key methods:

  • has_headers() - Returns effective header status (override or detected)
  • toggle_header() - Toggles the current header state
  • set_header_override(bool) - Sets manual override
  • clear_header_override() - Returns to auto-detect mode

Table Rendering

The table uses ui.add_sized() for proper column alignment:

// Each cell takes exact calculated width
let response = ui.add_sized(
    Vec2::new(cell_width, row_height),
    egui::Label::new(text).sense(Sense::hover()),
);

Column widths are calculated from content and clamped between MIN_COLUMN_WIDTH (50px) and MAX_COLUMN_WIDTH (300px).

Status Bar Toggle

Located next to the delimiter picker, shows:

  • Headers: ✓ - Header row enabled
  • Headers: ✗ - Header row disabled
  • ✓ suffix indicates manual override

Popup menu options:

  1. Auto-detect (default)
  2. First row is header
  3. No header row

Usage

  1. Open any CSV/TSV file in Ferrite
  2. Header detection runs automatically on first render
  3. Click "Headers: ✓/✗" in status bar to toggle or override
  4. Select "Auto-detect" to return to automatic behavior

Test Coverage

Test Description
test_detect_header_row_clear_headers Text headers with numeric data
test_detect_header_row_numeric_first_row All-numeric first row
test_detect_header_row_keyword_headers Common header keywords
test_detect_header_row_single_row Single row defaults
test_detect_header_row_empty Empty data defaults
test_detect_header_row_mixed_content Mixed first row
test_is_numeric_value Numeric detection patterns
test_csv_viewer_state_header State management