This quick guide is intended to walk you through the process of setting up your first Manakin theme. The first part will take you from the process for creating a blank new theme, configuring that theme, and finally installing it to apply to specific DSpace pages in order to set the stage for further development. The second part will cover some useful debugging and development methods as well as some common "gochasgotchas".
Part 1: Creating a new theme
Before you begin work on CSS or XSL changes, the newly created theme should also be installed. A theme is installed by adding an entry for it in the xmlui.xconf file, found in your DSpace config directory. Locate the <themes> block inside the xmlui.xconf and add an entry to your own theme there. The theme's location is specified by the path attribute while the set of DSpace pages it applies to can be specified in thee three different ways:
- With regex pattern:
<theme name=" Theme's name" regex="community-list" path=" YourThemeDir /"/>
- Directly with a handle:
<theme name=" Theme's name" handle="123456789/42" path=" YourThemeDir /"/>
- Or both:
<theme name=" Theme's name" regex="browse-title^" handle="123456789/42" path=" YourThemeDir /"/>
<map:transform type="IncludePageMeta"> <map:parameter name="stylesheet.screen#1" value="style.css"/> <map:parameter name="stylesheet.screen#3" value="style-ie6.css"/> <map:parameter name="stylesheet.screen#2" value="style-ie.css"/> ... </map:transform>
The syntax of the paramer parameter statement is as follows. The format for a parameter name must follow the form:
A very simple gocha gotcha that is bound to get any developer working with XML at least once is the single restriction XML places on its comments. In XML (and therefore XSL) syntax, comments as designated by the pair <!-- comments -->. The character sequence – (dash dash) cannot appear inside the XML comment section and its inclusion will throw an error. Some processors do not explicitly report the exact line where the offending character sequence occurs, instead pointing the developer to the beginning or the end of the entire comment block. In general, if you are getting a malformed XML error somewhere in the comment block, a simple string search for a double dash should fix the problem.
One of the more common entities used in HTML is the non-breaking white space, used to offset text and pad empty elements. While it is defined in XHTML as
→ etc.), the XSL processor will throw an error if those entities are used in the XSL code. The reason for this is that only the following five entities are explicitly defined in XML, mostly because the symbols are part of the syntax structure:
In order to insert other symbols into the HTML, use the ISO 8859-1 codes for those entities, i.e.
U+00A0 instead of
U+00A9 instead of
©. A full list of entities and their corresponding codes can be found in section 24 of the W3C Recommendation for HTML4: http://www.w3.org/TR/html401/sgml/entities.html
Since the question of what constitutes a complex vs. a simple match is processor-specific, the safest way to ensure desired behaviour is through explicit priorities. Thus, for empty lists in our example, all three templates might match a given element, but the one designed to match the specific case wins because it is explicitly given a higher priority. If you look through the templates in the
dri2xhtml.xsl file itself, you will notice many templates bearing a priority attribute to disambigute disambiguate cases where their match sets intersect.
A problem may arise, however, when these templates are imported into another stylesheet, as is the case in all themes overriding templates from the
dri2xhtml base library. Because templates belonging to the importing stylesheet have higher priority than those that are being imported (which is what allows the original templates to be overridden in the first place), this can produce unintended consequences when overriding only the simple and low-priority templates. Using our example above, we cannot just override the template than matches all lists if we also wish to preserve the original behaviorbehaviour, because it will always override the more specific ones simply by the virtue of having higher import priority. For this reason, when overriding simple templates for a particular element, always make sure that the templates dealing with the more esoteric conditions for that element are imported as well, even if you do not intend to change them.
The last thing to point out here is the use of the "mode" attribute on templates. These are used to differentiate templates that apply to the exact same elements, usually to process the same element under different conditions. In order to match, a template's mode must correspond to the mode of the template call, so a call of the form
<xsl:apply-template select="dri:list" mode="nested"/> will only match templates that have the same mode attribute, i.e.
<xsl:template match="dri:list" mode="nested">. This pairing overrides all other templates, regardless of priority and import precedence, so it is generally advisable to preserve the modes in imported templates. If the modes are kept consisentconsistent, however, those templates are subject to the same disambiguation rules as templates with modes.