r-flextable

# R flextable ## Overview **flextable creates publication-quality tables that render consistently across Word, PowerPoint, HTML, and PDF.** Core principle: Separate data from display. Build from a data.frame, then layer formatting declaratively using selectors. ## References Read `references/API.md` before writing code. - `references/API.md` - Complete function reference - `references/overview.md` - Core concepts and workflow - `references/formatting.md` - Styling and appearance - `references/layout.md` - Structure and merging - `references/selectors.md` - Targeting cells for formatting - `references/output.md` - Rendering to different formats ## When to Use **Use flextable when:** - Output to Word/PowerPoint required - Need cell merging, conditional formatting, mini charts - Cross-references and auto-numbered captions - Same table across multiple formats **Consider alternatives:** - HTML-only: gt or reactable - LaTeX-heavy: kableExtra - Interactive dashboards: DT ## Quick Reference | Task | Function | |------|----------| | Create table | `flextable(df)` | | Format numbers | `colformat_double()`, `colformat_int()` | | Bold/italic/color | `bold()`, `italic()`, `color()` | | Background color | `bg()` | | Merge cells | `merge_v()`, `merge_h()`, `merge_at()` | | Add header | `add_header_row()` | | Auto-size | `autofit()` | | Apply theme | `theme_vanilla()`, `theme_zebra()` | | Save to Word | `save_as_docx()` | | Save to PowerPoint | `save_as_pptx()` | ## Core Pattern ```r library(flextable) # Create -> format -> output ft <- flextable(head(mtcars, 5)) |> colformat_double(digits = 1) |> # Conditional formatting with formula selectors color(i = ~ mpg > 20, j = "mpg", color = "darkgreen") |> bold(i = ~ mpg > 20, j = "mpg") |> # Spanning header add_header_row( values = c("Performance", "Engine", "Transmission"), colwidths = c(2, 4, 5) ) |> theme_vanilla() |> autofit() save_as_docx(ft, path = "table.docx") ``` ## Selectors (Key Concept) Target cells for formatting: ```r # Row selector (formula) bold(ft, i = ~ cyl == 6) # Column selector bg(ft, j = ~ mpg + hp, bg = "lightgray") # Part selector bold(ft, part = "header") ``` See `references/selectors.md` for details on multi-content cells, mini charts, output-specific notes. ## Common Mistakes | Mistake | Fix | |---------|-----| | Theme doesn't format new header | Apply theme AFTER `add_header_row()` | | `autofit()` overflows margins | Use `set_table_properties(layout = "autofit")` | | `height()` has no effect | Set `hrule(rule = "exact")` first | | Formula selectors fail in header | Use integer indices for header rows | | Images missing in Word | Use `officedown::rdocx_document()` | | PDF ignores padding | Use `ft.tabcolsep` chunk option | | `add_header_row` values wrong | One value per span; colwidths sum to ncol | ## Advanced See `references/` for: - **API.md**: Complete function reference (240+ functions) - **selectors.md**: Multi-content cells, mini charts, output-specific notes - **formatting.md**: All formatting functions and options - **layout.md**: Merging, sizing, headers/footers - **output.md**: Rendering to all formats