# Advanced configuration
❗️ This page works with URL rewriting enabled ❗️

By default, the same style is used for all the pages, //htmgem/css/htmgem.css//, except when a file having the same name as the page but with the extension **.css** exists in the same directory. In such as case, it's used.

When the CSS option is activated in the configuration (see /rewrite// below) other behaviors are possible. **Beware**, it won't work with a Gemini client as HtmGem is only reachable with a web browser.
* &style=**htmgem** : Uses the default style.
* &style=**none** : The page HTML is sent without style.
* &style=**<autre nom>** : The file htmgem/css/<autre nom>.css is used as a style.
* &style=**/<path>** : The provided file (absolute path) is used as a style.
* &style=**source** : The source code of the page is sent to the browser, see below…
* &style=**pre** : The source code of the page is sent to the browser enclosed in //<pre>//, see below…

## URL rewriting to set the style to use

Modifying the web server configuration works but it's rather heavy. It's possible to test a particular style this way:
> https:/​/site.tld/htmgem/index.php?url=/url/page.gmi&style=<…>

It's also possible to make a URL rewriting which incorporate the style:
> rewrite ^(.+\.gmi)$ /htmgem/index.php?rw=1&url=$1;
> rewrite ^(.+\.gmi)\ *\|\ *([\w_]+)$ /htmgem/index.php?rw=1&url=$1&style=$2;

For instance, when it's activated:
=> configuration-en.gmi%20|%20pre Shows the readable source code on the screen, using the markup **<pre>**.
=> configuration-en.gmi%20|%20source configuration-en.gmi | source : Downloads the source code.

### With style already included…

=> configuration-en.gmi%20|%20htmgem Style //HtmGem//, the default style
=> configuration-en.gmi%20|%20none Style //none//
=> configuration-en.gmi%20|%20terminal Style //terminal//
=> configuration-en.gmi%20|%20black_wide Style //black wide//
=> configuration-en.gmi%20|%20simple Style //simple//
=> configuration-en.gmi%20|%20raw Style //raw//
=> configuration-en.gmi%20|%20debug Style //debug//

=> ../css Style selector: the page containing the style allows to test them 😎

## Text decoration

The text decoration, which interprets the **bold** for instance, is not part of GemText definition. The text decoration applies everywhere except on the titles and preformated texts.

### Disable the text decoration

It's possible to:
* disable and enable the text decoration with a line **^^^**,
* add what follows to the URL **rewriting**:
> &textDecoration=0

## BNF / Syntax

HtmGem uses a precise implementation of the GemText BNF. It indicates exactly what text portions are to be used.
=> BNF-en.gmi BNF

=> tutogemtext-en.gmi How to build GemText pages?

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Amongst the distributed files and directories, only the ones below are useful for HtmGem:
* **htmgem/*.php** : These files translate the GemText to HTML.
* **htmgem/css/htmgem.css** : If it's missing, the display will be without style — literally.
* **htmgem/css/…** : Keep the styles you use.
The others can be deleted (included this present file //configuration-en.gmi//) although they are not harmful.