---
title: "Recipes"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Recipes}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

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

library(linne)
```

## Introduction

This vignette walks the user through some applications of linne.

## Shiny Inputs

Shiny developers often want to customise how shiny inputs look and feel, which can be a bother. Let's say we want to change the label color of the `textInput` shiny input.

```r
shiny::textInput(inputId = "text", "Label") 
```

```{r}
cat(as.character(shiny::textInput(inputId = "text", "Label")))
```

One might be tempted to only use `sel_id('text')`, as demonstrated above, this would not work. We could instead use on of the infix operators select the child tag "label" of the input.

```{r}
Linne$new()$
  rule(
    sel_id("text") %child% sel_tag("label"),
    color = "#f4a717"
  )$show_css()
```

Now, just to demonstrate what is possible with CSS, say we want to change the font size of a specific option in a `selectInput`.

```r
shiny::selectInput("select", "Select one:", choices = letters[1:3]) 
```

```{r}
cat(as.character(shiny::selectInput("select", "Select one:", choices = letters[1:3])))
```

We can again use a combination of selectors to select say, option "b", to a different size.

```{r}
Linne$new()$
  rule(
    sel_id("select") # inputId = "select"
      %child% 
      sel_attr("value", "b"), # value = 'b'
    color = "#f4a717"
  )$show_css()
```

> A good way to conceptualise the `%child%` operator is to think of it like one uses the pipe in the [rvest](https://github.com/tidyverse/rvest) package or how one might use the pipe in [purrr](https://github.com/tidyverse/purrr): to gradually but surely go down the tree until the right node is selected.