---
title: "Constructing tables"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Constructing tables}
  %\VignetteEncoding{UTF-8}
  %\VignetteEngine{knitr::rmarkdown}
editor_options: 
  chunk_output_type: console
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r, echo=TRUE, message=FALSE, warning=FALSE}
library(gapminder)
library(dplyr)
library(tidyr)
library(stringr)
library(purrr)
library(gt)
library(mmtable2)
```

## Adding headers

You can add headers using data from a column in your data frame. 

Its placement will depend on your your choice of header_* functions.

Header options include: top, top_left, left, and left_top. 

Here's an example. 
```{r message=FALSE, warning=FALSE, echo = T}
style_list <- list(cell_borders(sides = "top",color = "grey"))
style_list2<- list(cell_borders(sides = "left",color = "grey"))
gm_df <- gapminder_mm %>% filter(var != "Life expectancy")
style_list3 = list(cell_text(align = "left"))

gm_table <- 
 gm_df %>% 
  mmtable(cells = value) +
  header_left(year) +
  header_top(country) +
  header_left_top(var)  +
  header_top_left(continent)  +
  header_format(header = var, scope = "table", style = style_list) +
  header_format(continent,style_list3)

print(gm_table)
```