# gfonts

    library(gfonts)

{gfonts} allow you to use a Google font to use it offline in a Shiny application or a R Markdown document. You can download a font via google-webfonts-helper and generate appropriate CSS to use it.

## Setup a font to use in your project

In your project directory, use `setup_font` once to download a font and generate CSS code. For example to use the Roboto font, you can do :

    setup_font(
      id = "roboto",
      output_dir = "www",
      variants = "regular"
    )

In a Shiny application you can use `www/` folder, for R Markdown, create a sub-folder at the same level as your `.Rmd` file.

`setup_font()` will create two sub-folders, containing the following files :

    www
    +-- css
    |   \-- roboto.css
    \-- fonts
        +-- roboto-v20-latin-regular.eot
        +-- roboto-v20-latin-regular.svg
        +-- roboto-v20-latin-regular.ttf
        +-- roboto-v20-latin-regular.woff
        \-- roboto-v20-latin-regular.woff2

To know all fonts and their ids, you can use `get_all_fonts()` :

    head(get_all_fonts())
    #>                 id           family
    #> 1           roboto           Roboto
    #> 2        open-sans        Open Sans
    #> 3     noto-sans-jp     Noto Sans JP
    #> 4             lato             Lato
    #> 5       montserrat       Montserrat
    #> 6 roboto-condensed Roboto Condensed
    #>                                                                                                                                          variants
    #> 1                                                 100, 100italic, 300, 300italic, regular, italic, 500, 500italic, 700, 700italic, 900, 900italic
    #> 2                                                                 300, 300italic, regular, italic, 600, 600italic, 700, 700italic, 800, 800italic
    #> 3                                                                                                                100, 300, regular, 500, 700, 900
    #> 4                                                                 100, 100italic, 300, 300italic, regular, italic, 700, 700italic, 900, 900italic
    #> 5 100, 100italic, 200, 200italic, 300, 300italic, regular, italic, 500, 500italic, 600, 600italic, 700, 700italic, 800, 800italic, 900, 900italic
    #> 6                                                                                                 300, 300italic, regular, italic, 700, 700italic
    #>                                                                  subsets
    #> 1 cyrillic, cyrillic-ext, greek, greek-ext, latin, latin-ext, vietnamese
    #> 2 cyrillic, cyrillic-ext, greek, greek-ext, latin, latin-ext, vietnamese
    #> 3                                                        japanese, latin
    #> 4                                                       latin, latin-ext
    #> 5                   cyrillic, cyrillic-ext, latin, latin-ext, vietnamese
    #> 6 cyrillic, cyrillic-ext, greek, greek-ext, latin, latin-ext, vietnamese
    #>     category version lastModified popularity defSubset defVariant
    #> 1 sans-serif     v20   2019-07-24          1     latin    regular
    #> 2 sans-serif     v18   2020-09-15          2     latin    regular
    #> 3 sans-serif     v28   2020-11-12          3     latin    regular
    #> 4 sans-serif     v17   2020-09-15          4     latin    regular
    #> 5 sans-serif     v15   2020-09-15          5     latin    regular
    #> 6 sans-serif     v19   2020-09-15          6     latin    regular

## Use a font

To use a downloaded font, you can use in your UI or in a chunk :

    use_font("roboto", "www/css/roboto.css")

First argument is the id of font downloaded, second is path to CSS file generated.

An other solution in Shiny application is to import the CSS file in a link tag and add a style tag:

    fluidPage(

      tags$link(rel = "stylesheet", type = "text/css", href = "css/roboto.css"),
      tags$style("body {font-family: 'Roboto', sans-serif;}")

    )

In Markdown, import CSS file in yaml header, and add a CSS chunk :

    ---
    output:
      html_document:
        css: assets/css/roboto.css
    ---

    ```css
    body {font-family: 'Roboto', sans-serif;}
    ```

## Download a font

If you only want to download a font, you can use:

    download_font(
      id = "roboto",
      output_dir = "azerty",
      variants = c("regular", "300italic", "700")
    )

## Generate CSS

To download CSS code to import a font in HTML, you can use:

    generate_css("roboto", "regular", font_dir = "path/to/font")

    #> @font-face {
    #>   font-family: 'Roboto';
    #>   font-style: normal;
    #>   font-weight: 400;
    #>   src: url('path/to/roboto-v20-latin-regular.eot'); /* IE9 Compat Modes */
    #>   src: local(''), local(''),
    #>        url('path/to/roboto-v20-latin-regular.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
    #>        url('path/to/roboto-v20-latin-regular.woff2') format('woff2'), /* Super Modern Browsers */
    #>        url('path/to/roboto-v20-latin-regular.woff') format('woff'), /* Modern Browsers */
    #>        url('path/to/roboto-v20-latin-regular.ttf') format('truetype'), /* Safari, Android, iOS */
    #>        url('path/to/roboto-v20-latin-regular.svg#\1') format('svg'); /* Legacy iOS */
    #> }

The path must be relative to the one were this code is saved.