Modular Layout in ZOPESilva

1
Modular Layout in ZOPE/Silva

• Problem How can one redefine only a part (e.g.
  regions A,B,C in the picture) of the web page
  layout in a subfolder without duplicating any
  reused (e.g. regions H, N, F in the picture)
  layout parts?
• Solution The ZOPE macro-slot filling mechanism
  is not powerful enough as it does not allow to
  that only a few slots (defined in content.html)
  are overridden in a subfolder. Hence, we split
  the layout_macro.html into several
  filesmain.html contains the layout of regions
  A, B, C and layout_macro.html contains the layout
  of regions H, N, F.
• Now, main.html (which actually defines the
  contents of a table cell in layout_macro.html)
  can be overriden (thanks to ZOPEs acquisition)
  in subfolders and the rest of the layout can be
  reused. The inclusion of main.html into
  layout_macro.html happens through macro
  expansion. On the following pages, a possible
  implementation is shown and main.html is even
  split into further files (region B and C get
  their own layout files) for full flexibility.In
  order to use some default fallback files for
  non-existing layout-files, we use a small python
  script to generate the path to each layout file.

H
B
A
F
2
Reusable and modular Content/Layout Templates
Fill-slot meta Fill-slot nav Fill-slot
footer
define-macro ethlife
content_macro_ ethlife.html
define-macro fav_links
content_macro_ fav_links.html
content.html
main.html
defines macro-slots for Header Navigation
and Footer
define-macro main
layout_macro.html
content_macro_ main.html
3
Reusable and modular Content/Layout Templates
lthtml metaluse-macro /layout gt ltsilva
metalfill-slot meta gt
lthtml metaldefine-macro layout gt ltmetal
block define-slotmeta gt ltTABLE
metaluse-macro here/main.html/ macros/maingt
lt/TABLEgt
ltTABLE metaldefine-macro main gt ltspan
talomit-tag taldefinemacropath
pythonpath( here.getContentPath( ethlife))gt
ltspan metaluse-macro macropathgt
lt/spangt lt/spangt ltspangt fav_links
lt/spangt lt/TABLEgt
ltspan metal define-macro ethlife gtlt/spangt
content_macro_ ethlife.html
ltspan metal define-macro fav_links gtlt/span
gt
content.html
defines macro-slots for Header Navigation
and Footer
content_macro_ fav_links.html
layout_macro.html
main.html
4
Python script for path generation

• getContentPath(macroname)
• Returns a list of paths that lead to content
  macros
• (c) 4.12.2002, Thomas Duebendorfer, GNU GPL
• The returned list of ""-separated paths make
  ZOPE do the following
• 1. Use override Mechanism (no traversal)
• Use macro ltmacronamegt in override_ltcontent_m
  acrogt if it exists at the request path location
  (no traversal).
• If file exists but has not the searched
  macro in it, then call macro "bad_override" in
  file ltcontent_macros_filegt.
• 2. Find macro ltmacronamegt by traversing the
  hierachy
• Look at the first file named
  ltcontent_macrogt starting at request path location
  and call macro ltmacronamegt in it.
• On error Look for a file
  ltcontent_macros_filegt and call macro ltmacronamegt
  in it.
• On error Call macro "no_contents" in file
  ltcontent_macros_filegt.
• Note The default filename for a macro with
  name ltmacronamegt is ltcontent_macro_prefixgt
  ltmacronamegt '.html'
• override_prefix 'override_'
• content_macro_prefix 'content_macro_'
• content_macros_file 'content_macros.html'
• nocontentsmacro content_macros_file
  '/macros/no_contents'