Spreadlinks 0.4.1
A Django app for serving libraries of links from spreadsheets.

Spreadlinks - publish links from a spreadsheet
==============================================

Given a spreadsheet of links to resources on the web, this Djang app displays
the links with a simple navigation system using tags to narrow the list down
to resources with matching tags.

There are examples on [spreadsite.org][].

  [spreadsite.org]: https://spreadsite.org/


How it Works
------------

A 'resource library' is a collection of links to resources on web sites (either
the same as this site or external sites). A library is defined by a directory
containing, at minimum, a spreadsheet with data about the links in it. Other,
optional, files may add more metadata to flesh out the definition.

Libraries are named after the directory. Libraries all live in a 'root
directory'. For the sample app, the root is `resource-libraries` and the Fan
films library is in `resource-libraries/fanfilms`.

The standard Drupal URLconf in `spreadlinks/urls.py` has these lines:

    urlpatterns = [
        url(r'^$', spreadlinks.views.library_list,
            {'root_dir': settings.SPREADLINKS_DIR}, 'library_list'),
        url(r'^(?P<library_name>[^/]*)/$', spreadlinks.views.library_detail,
            {'root_dir': settings.SPREADLINKS_DIR}, 'library_detail'),
        url(r'^(?P<library_name>[^/]*)/page(?P<page>[0-9]+)$', spreadlinks.views.library_detail,
            {'root_dir': settings.SPREADLINKS_DIR}, 'library_detail'),
        url(r'^(?P<library_name>[^/]*)/tags/(?P<urlencoded_keywords>[a-z_0-9+:-]+)$', spreadlinks.views.library_detail,
            {'root_dir': settings.SPREADLINKS_DIR}, 'library_detail'),
        url(r'^(?P<library_name>[^/]*)/tags/(?P<urlencoded_keywords>[a-z_0-9+:-]+)/page(?P<page>[0-9]+)$', spreadlinks.views.library_detail, {'root_dir': settings.SPREADLINKS_DIR}, 'library_detail'),
    ]

Each view takes an argument that is the root directory; in this case it is in
turn acquired from the web site settings. The library name will match one of its
subdirectories. I recommend using short names consisting only of lowercase
letters and numbers; it keeps the URLs tidy.

Data Format
-----------

At present the spreadsheet must be in comma-separated values form; this is just
because I have not bothered adding support for one of the Excel-parsing libraries
available for Python. The first row MUST be column headings. Each of the
subsequent rows specifies an entry in the library.

The meaning of the columns is inferred from the column heading. Column headings
are normalized to lower case and spaces replaced with underscores before
interpreting them. The following columns are significant:

- `title`: The title of the link. Should be one line long and will be unique.
- `description`: A paragraph or two describing the link. Markdown format.
- `url`: The location of the item.
- `image-url`: A picture to illustrate the item.
- `href` or `url`: The address of the resource being linked to.
- `keywords` or `main_keywords`: Keywords in the Main facet (see below)
- `FACET_keywords`: Keywords in an additional facet (where FACET is
  replaced with the name of that facet).

At present other columns are ignored. (Probably they should be displayed as part
of the link description or something.)

Keywords are used to build a browseable drill-down navigation thingummy.
The navigator automatically hides keywords that would lead to no matches.

A _facet_ is a collection of keywords that describe the resource in the same
way. You might use a secondary facet to
describe the resource type, or the intended audience, say. The navigator allows
the user to select keywords from separate facets independently.

The value of the keywords cells may contain multiple keywords. By default,
keywords are required to go one per line within the cell; this allows for
keywords to be normal phrases with spaces and punctuation.

Metadata
--------

Additional information about the library may be specified with a separate file
`METADATA.txt`. This contains one or more headings following the RFC-2822 format
of heading:value, followed by a blank line and then the description of the
library. The description uses Markdown format.

The following headers are understood:

- `Title`: A title for the library as a whole.
- `Keyword-Separator`: A character to use instead of newlines to separate
keywords in the data file.

If there is no `METADATA.txt`, or no title is specified, then it uses library name
(the same as the directory name).