AutoSuggest

AutoSuggest

Get an autocompleting dialog underneath basic search boxes.

If activated, the dialog appears in both the JavaScript OPAC and the Template
Toolkit OPAC.

Mike Rylander and Bill Erickson largely designed and spec'ed out this
feature, especially at the database level.  Lebbeous Fogle-Weekley and
Mike Rylander did the programming.

How it works, for site administrators
-------------------------------------

Once the code is installed, including database stored procedures,
(re)ingesting your bibliographic records will populate two new tables
needed by AutoSuggest: metabib.browse_entry and metabib.browse_entry_def_map.

Yes, for now this means that the size of your database in per-record terms
will be greater.  The browse_entry data we generate is extremely similar to
facet data, so it's possible that in the future we can blend them into the
same thing at the database level, and save some space.

To control what gets indexed in the metabib.browse_* tables, set the
boolean 'browse_field' column for each row in config.metabib_field as desired
Numbers 15 (keyword|keyword) and 16 (subject|complete) should generally be set
to false.

The config.metabib_class  table has a new 'bouyant'
column.  Setting this to true means that when a user is typing in the OPAC
search box with a search class selector set to, say, 'Subject', and the cmc row
for 'Subject' has 'bouyant' set to true, the top suggestions will definitely
come from the Subject fields of MARC records (if any).  'restrict' is like
'bouyant', only stronger.  In that case suggestions /only/ come from the
selected class.

This is the idea behind the 'restrict' column (in both the
config.metabib_class table and the config.metabib_field table):
For any given class or field, if restrict is true AND the user at the OPAC
has selected that same class or field from the search class dropdown, then
autosuggestions will only come from that class or field in the record.

You never want this column to be true for keyword, because we don't index
keywords for browse/autosuggest purposes (we would get giant blobs of
information as autosuggestions, and you don't want that (really)).

You don't really want it to be true for most classes and fields.
If the user sets the dropdown to "subject" and start typing "harry potter",
the user really wants matches from the "title" class too (although other
things being equal, matches from the "subject" class will rise to the top).

If you have a speciality index, you *may* want to set restrict to true
for that particular field.  For a song title index, for example.  To take
advantage of this, you would also have to customize your OPAC to have an
entry in the search class dropdown for 'title|songtitle' (or whatever's
appropriate for your specialty index).  This is easy to do and should be
covered somewhere in documentation for both the JSPAC and the TPAC.

The order of suggestions otherwise has mostly to do with how well what users
have typed matches what's in your bib records, and the value of the weight
column of the relevant config.metabib_field row.  Examine the code if you're
curious to know more or want to make adjustments.

The master on/off switch for AutoSuggest is a new row in in config.global_flag
named 'opac.use_autosuggest'.  Set its 'enabled' column to false to turn
off AutoSuggest.  If you don't want your suggestions to be limited to whatever's
OPAC visible at the search org, set the 'value' column to anything that
does not contain the string 'opac_visible'.  This could be a good idea
if AutoSuggest seems slow on a large site.

Turning this on means introducing Dojo in your TPAC.  I tried to
keep it minimal, for load time's sake.  There's no fieldmapper or IDL stuff
play.  For now, turning this feature off will avoid loading Dojo in your
TPAC.

Managing the little stuff
-------------------------
CSS classes that affect the look of suggestions are in this file for the TPAC:
    Open-ILS/web/css/skin/default/opac/style.css

and in this file for the JSPAC:
    Open-ILS/web/opac/skin/default/css/layout.css

At bottom, autosuggest is shaped by PostgreSQL's Full Text Search features.
Some of the arguments that are passed to TS_RANK_CD() and TS_HEADLINE() are
expoposed via options to the openils.widget.AutoSuggest and
openils.AutoSuggestStore modules, which have comments.  You can customize your
OPAC files to invoke these with your desired options without touching much
actual code.

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>