Theme basics

With the 1.5 themes we can build great Moodle learning environments - our learners will appreciate it. I'm looking forward to see those many good useable and different and attractive looking Moodle learning sites. I know learning with fun is better learning ;-)

Urs Hunkler 12:36, 1 Aug 2005 (Westeuropäische Sommerzeit)

What is inside the themes folder?

The themes folder contains the following:

pix/
config.php
favicon.ico
footer.html
header.html
styles.php
styles_color.css
styles_fonts.css
styles_layout.css
styles_moz.css

The pix folder

This contains all pictures and icons used in the theme. The 1.5 themes come with pictures for the tabs and eventually for the gradients. (All Moodle 1.5 themes use the pix folder.)

The favicon.ico

This is the small icon shown in the browsers in front of the URL (as for 1.4).

header.html and footer.html

These contain your logo, the login, the jumpto menu, the breadcrumb navigation, the moodle logo etc. Within these files you can give Moodle your individual look at the top and the bottom of all pages (as for 1.4).

These are the main variables available for use in these files:

$CFG  (object with all system variables)
$THEME (object with all current theme variables from config.php)
$course (current course object)
$meta (all the meta tags, including stylesheets)
$home (boolean)
$title (page title)
$heading (heading for the page)
$navigation (the raw navigation "breadcrumbs")
$navmenulist  (xhtml )
$menu (the popup menu or button)

Header only:

$direction (ltr or rtl)
$bodytags (tags that need to be added to the body)

Footer only:

$homelink (link back to "home" - current course page or site page)
$loggedinas (string with name of user as link)
$performanceinfo (string with performance information)

Finally, the header and footer can contain any Moodle PHP code, so all sorts of other data can be extracted from the database or environment as necessary.

styles.php

This has the same name as in 1.4 but takes another task in 1.5. It is called from header.html and builds the bridge to the CSS files. You don't need to edit anything.

config.php

This also has the same name as in 1.4 and another task in 1.5. In this file you configure how the CSS files work together. You can build your theme onto the standard or onto any parent theme and can include or exclude several CSS files.

The stylesheets

With Moodle 1.5 started the work to clearly separate content from presentation for better flexibility, accessibility and for more flexible page design. To give you the chance to work relatively easy for few changes of color and fonts the CSS is separated into three files:

styles_layout.css
styles_fonts.css
styles_color.css

In addition, styles_moz.css contains Firefox and Mozilla specific formatting, especially the rounded corners.

Additional files in the themes folder

Last but not least theme designers can provide information about the theme and a picture preview. The picture preview is shown as preview on the theme configuration page, the info in the README file after the theme has been selected.

README.html
screenshot.jpg

Separating content from presentation

The content layer of the page is represented via XHTML, the presentation layer via CSS. To connect the belonging information in both layers XHTML tags and named hooks within page are used. You need quite a lot of them to style complex web applications like Moodle.

Cascading CSS

Moodle themes use style sheets to describe the Moodle "look" by controlling the layout, fonts and colors. These are constructed by a PHP script called "styles.php" in each theme directory, and controlled by a file called "config.php" in the same place.

Moodle has a "standard" theme which is very plain and provides a basic layout for other themes to build on. Each theme may also have a "parent" theme, which will be included before the current theme.

So, depending on your settings, you may have up to three stylesheets for a theme:

1. "standard" theme - theme/standard/styles.php
2. "parent" theme - theme/parenttheme/styles.php
3. "main" theme - theme/yourtheme/styles.php

Due to the cascading character of CSS the definitions in later files can overwrite the definitions in the earlier CSS files. Moodle makes extensive use of the cascading character of CSS and gives the theme designer many opportunities. They range from easy development of themes based on the existing ones with few changes up to the design of a completely individual Moodle appearance with new CSS files.

Theme designers can define and add any CSS stylesheets and name them any way as needed for this theme.

The standard theme

Figure 1: The theme "standard" with the CSS files "styles_layout.css", "styles_fonts.css", "styles_color.css" and "styles_moz.css".

Small changes

If you just want to make small changes to a theme like using different colors or adding a logo then your new theme will include the "standard" theme and you define a few extra CSS styles in a new CSS file.

As an example, see the "standardwhite" theme.

It uses the file "config.php" to set the appropriate options. The first entry $THEME->sheets = array('gradients'); defines the CSS file "gradients.css" as the file with additional CSS definitions. It also specifies $THEME->standardsheets = true; which says to include all the styles from the standard theme too.

Instead of basing the theme on "standard", you could base it on another theme by specifying $THEME->parent = 'cooltheme';

Figure 2: The theme "standardwhite" with all CSS files from the theme "standard" plus "gradients.css" from the selected theme.

Mixed CSS - standard layout plus you own fonts and colours

The theme "formal_white" mixes the page layout from the theme "standard" with its own layout, fonts and colours. This way all layout changes in the standard Moodle layout are kept. This is done by setting $THEME->sheets = array('fw_layout','fw_color','fw_fonts'); and $THEME->standardsheets = array('styles_layout'); in the config file.

Figure 3: The theme "formal_white" with the CSS file "styles_layout.css" from the theme "standard" and the individual files "fw_layout.css", "fw_fonts.css", "fw_color.css".

A theme using a parent theme (faked)

An advanced feature is to set any existing theme as the "parent" theme and offer variant themes to this. Two possible uses can be to design one "parent" theme with all CSS definitions. Then offer "child" themes with color variants to be chosen by the users according to their color preferences. These "child" themes need only one CSS file holding the different color definitions. Or create "child" themes which only vary in the logo/banner placed in the "header.html". These "child" themes do not need their own CSS files.

The configuration for the "child" themes could look like $THEME->sheets = array('my_layout');, $THEME->parent = 'formal_white'; and $THEME->parentsheets = array('fw_layout','fw_color','fw_fonts');

Figure 4: The faked theme "formal_white_plus" with the additional CSS file "my_layout.css".

A theme without standard dependencies (faked)

This theme would use its own CSS. The settings $THEME->sheets = array('styles_layout', 'styles_fonts', 'styles_color'); and $THEME->standardsheets = false; deactivate all other Moodle CSS and make a completely independent theme. All changes in the standard Moodle theme do not change this theme at all.

Figure 5: The theme with it's own CSS files "styles_layout.css", "styles_fonts.css" and "styles_color.css".

Some more basic CSS files

In addition to theme CSS files, Moodle features a basic CSS file for every module, block and for every language. Developers can provide basic CSS properties for their modules and blocks to get the page or block layout right, if they need formatting for special functionality. The look and feel of Moodle is not changed by these layout basics.

These files are only loaded when the "standard" CSS is activated. They are loaded first before all theme CSS files.

Figure 6: The CSS file loading order of all Moodle CSS and theme CSS files.

Last but not least

Very good information about the Moodle CSS you can get from the final stylesheets that reach your browser. Moodle integrates some helpful documentation. For example you can read the CSS with the Firefox web developer extension.

External links

• Moodle Demo Course - this course enables you see how the different CSS files form the look of the page. On the top right you see four links on a green bar. With the buttons you can switch stylesheets off (font-style italic) and on (font-style normal). When you switch all stylesheets off you see the content level of Moodle.
• Moodle Theme Gallery
• Firefox Web Developer Extension