# Theme for shiny

    library(fresh)

{fresh} allow to customize themes to use with `shiny::fluidPage` or `shiny::navbarPage`. {shiny} use by default the theme from Bootstrap, {shinythemes} allow to use custom themes from Bootswatch. All these themes have default parameters (like colors) that {fresh} allow to edit.

## Create a theme

Use function `create_theme` to create a new theme, first argument is the default template you want to modify, after that you can use functions `bs_vars_*` to edit variables of Bootstrap elements :

    create_theme(
      theme = "default",
      bs_vars_button(
        default_color = "#FFF",
        default_bg = "#112446",
        default_border = "#112446",
        border_radius_base = "15px"
      ),
      bs_vars_wells(
        bg = "#FFF",
        border = "#112446"
      )
    )

Here we modify `shiny::actionButton` appearance with `bs_vars_button` and appearance of `shiny::sidebarPanel` with `bs_vars_wells`.

Result looks like :

## Use a theme

There’s two way to use a newly created theme :

1. inline in the UI (useful to quickly visualize your theme)
2. using a CSS file (recommended)

### Inline

Don’t specify an output file and use rsult of `create_theme()` in `use_theme()` directly in your application :

    navbarPage(
      title = "Custom navbar",
      header = use_theme(
        create_theme(
          theme = "default",
          bs_vars_navbar(
            default_bg = "#75b8d1",
            default_color = "#FFFFFF",
            default_link_color = "#FFFFFF",
            default_link_active_color = "#75b8d1",
            default_link_active_bg = "#FFFFFF",
            default_link_hover_color = "firebrick"
          ),
          output_file = NULL
        )
      ),
      tabPanel("Tab 1"),
      tabPanel("Tab 2")
    )

### File

When you create a theme, you can specify an output file :

    create_theme(
      theme = "default",
      ...,
      output_file = "my-custom-theme.css"
    )

Put the file `my-custom-theme.css` in the `www/` folder of your application, and reference it like that in your UI :

    fluidPage(

      theme = "my-custom-theme.css",

      # ...
    )

    # or if using a navbar page
    navbarPage(

      title = "My application",
      theme = "mytheme.css",

      # ...
    )