# Styling HTML output

 Tip Summary Clone the metanorma-generic gem Edit the html_generic_titlepage.html and html_generic_intro.html pages to match your organization’s branding. Leave the Liquid Template instructions alone ({{…​}}, {%…​%}) unless you know what you’re doing with them: they are how the pages are populated with metadata. Edit the default_fonts() and googlefonts methods in your IsoDoc::…​::HtmlConvert class, to match your desired fonts. Edit the default_file_locations() method in your IsoDoc::…​::HtmlConvert class, to match your desired stylesheets and HTML templates. Edit the htmlstyle.css stylesheet to match your organization’s branding. The classes already in place there are used to style existing blocks of text; refer to the sample documents included in the gem (spec/examples) for their use.

Styling of output is intended to be configurable:

• HTML stylesheets are expressed in SCSS, with their fonts populated through the default_fonts() method in the IsoDoc::…​::HtmlConvert class.

• Frontispiece content is templated, populated from the metadata parsed in the IsoDoc::…​::Metadata class, via Liquid templates.

• The default stylesheets and HTML templates themselves are nominated in the default_file_locations() method in the IsoDoc::…​::HtmlConvert class.

That means you can change the styling of output documents readily, so long as you are aware of the functionality of the stylesheet.

• Styling information is stored in the …​/lib/isodoc/html folder of the gem, and applies to both Word and HTML content. For HTML content, the relevant files are html_…​titlepage.html (title page HTML template), html…​_intro.html (introductory HTML template, typically restricted to Table of Contents), scripts.html (Javascript scripts), and htmlstyle.css (the HTML stylesheet).

• The styling files to be loaded in are set in the default_file_locations() method of IsoDoc::…​::HtmlConvert. The files can be overridden through document variables in the AsciiDoc document.

• Additional files (e.g. logos) can be loaded in the initialize() method of IsoDoc::…​::HtmlConvert; for them to be access during document generation, they need to be copied to the working directory. (They can be removed subsequently by adding them to the @files_to_delete array. All image files are copied into an _html subdirectory.)

• The HTML templates are populated through Liquid Templates: variables in {{…​}} correspond to the hash keys for metadata extracted in IsoDoc::…​::Metadata, and its superclass IsoDoc::Metadata in the isodoc gem. See Metadata and Predefined text for more information.

• The SCSS stylesheets treat fonts as variables. Those variables are set in default_fonts(), which generates variable assignments for SCSS. Stylesheets normally recognize three fonts: $bodyfont for body text, $headerfont for headers and captions (which may be the same font as $bodyfont), and $monospacefont for monospace text. Note that default_fonts() takes the options passed to initialise HtmlConvert as a parameter; the document language and script can be used to make different font choices for different document scripts. (The existing gems refer to Latn, Latin script, and Hans, Simplified Chinese script.)

• Usually for HTML the fonts used are Web fonts. The HTML specifying the Web fonts used is set in googlefonts.

• Javascript scripts are populated in scripts.html; the scripts already in place in any gem you modify are in live use, and you should work out what they do before removing them. The AnchorJS script, for example, is used to generate navigable anchors in the document. (PDF is generated from HTML in Metanorma, but a distinct PDF-specific set of Javascript scripts can be specified as scripts-pdf.html.)

• The Javascript defining which headings to include in the HTML Table of Contents is defined in toclevel.

• Additional scripts and fonts may be loaded in the document head through the html_head() method of IsoDoc::…​::HtmlConvert. The existing gems use the document head to load jQuery, the Table of Contents generation script, any web fonts, and Font Awesome.

• The classes in the SCSS stylesheet correspond to static HTML content in the HTML templates, and dynamic HTML content in the IsoDoc::…​::HtmlConvert class, and its superclasses IsoDoc::HtmlConvert and IsoDoc::Common in the isodoc gem.

An HTML document is populated as follows:

• HTML Head wrapper (in IsoDoc::HtmlConvert)

• html_head() content

• @htmlstylesheet CSS stylesheet (expected to be in SCSS, generated from SCSS in the generate_css() method of Isodoc::HtmlConvert).

• HTML Body

• @htmlcoverpage HTML template (optional, corresponds to html_…​_titlepage.html)

• @htmlintropage HTML template (optional, corresponds to html_…​_intro.html)

• Document proper (converted from Metanorma XML)

• MathJax script, for rendering MathML and AsciiMath,

and Google Code Prettify, for highlighting sourcecode.

• @scripts Javascript Scripts (optional, corresponds to scripts.html)