CGI::Widget::DBI::Search - Database search widget


NAME

CGI::Widget::DBI::Search - Database search widget


SYNOPSIS

  use CGI;
  use CGI::Widget::DBI::Search;
  my $q = CGI->new;
  my $ws = CGI::Widget::DBI::Search->new(q => $q);
  # database connection info
  $ws->{-dbi_connect_dsn} = 'DBI:Pg:dbname=my_pg_database;host=localhost';
  $ws->{-dbi_user} = 'pguser';
  $ws->{-dbi_pass} = 'pgpass';
  # what table to use in the SQL query FROM clause
  $ws->{-sql_table} = 'table1 t1 inner join table2 t2 using (key_col)';
  # optional WHERE clause
  $ws->{-where_clause} = 'WHERE t1.filter = ? OR t2.filter != ?';
  # bind params needed for WHERE clause
  $ws->{-bind_params} = [ $filter, $inverse_filter ];
  # what columns to retrieve from query
  $ws->{-sql_retrieve_columns} =
    [ qw/t1.id t1.name t2.long_description/, '(t1.price + t2.price) AS total_price'];
  # what columns to display in search results (with header name)
  $ws->{-display_columns} =
    { id => "ID", name => "Name", long_description => "Description", total_price => "Price" };
  $ws->{-numeric_columns} = { id => 1 };
  $ws->{-currency_columns} = { total_price => 1 };
  $ws->{-show_total_numresults} = 1;
  # execute database search
  $ws->search();
  # output search results to browser
  print $q->header;
  print $q->start_html;
  # show search results as HTML
  print $ws->display_results();
  print $q->end_html;


DESCRIPTION

Encapsulates a DBI search in a Perl class, including all SQL statements required for performing the search, query results, HTML display methods, and multi-column, sortable result set displayed page-by-page (using HTML navigation links).


CONSTRUCTOR

new(@config_options)

Creates and initializes a new CGI::Widget::DBI::Search object. Possible configuration options:

Database connection options
  -dbi_connect_dsn      => DBI data source name (full connection string)
  -dbi_user             => database username
  -dbi_pass             => database password
  -dbi_host             => host to connect to database (overridden by -dbi_connect_dsn)
  -sql_database         => database to connect to (overridden by -dbi_connect_dsn)
Database retrieval options
  -sql_table            => Database table(s) to query,
  -sql_table_columns    => [ARRAY] List of all columns in sql_table,
  -sql_retrieve_columns => [ARRAY] List of columns for retrieval,
  -opt_precols_sql      => Optional SQL code to insert between 'SELECT' and
                           columns to retrieve (-sql_retrieve_columns).
                           This is commonly something like 'DISTINCT',
  -where_clause         => Literal SQL WHERE clause to use in SELECT state-
                           ment sent to database (may contain placeholders),
  -bind_params          => [ARRAY] If -where_clause used placeholders ("?"),
                           this must be the ordered values to use for them,
  -fetchrow_closure     => (CODE) A code ref to execute upon retrieving a
                           single row of data from database.  First arg to
                           closure will be calling object; subsequent args
                           will be the values of the retrieved row of data.
                           The closure's return value will be push()d onto the
                           object's results array, which is unique to a search.
                           It should be a hash reference with a key for each
                           column returned in the search, and values with the
                           search field values.
Search result display options
  -display_table_padding  => Size of HTML display table cellpadding attribute,
  -display_columns        => {HASH} Associative array holding column names as
                             keys, and labels for display table as values,
  -numeric_columns        => {HASH} Columns of numeric type should have a
                             true value in this hash,
  -currency_columns       => {HASH} Columns of monetary value should have a
                             true value in this hash,
  -unsortable_columns     => {HASH} Columns which the user should not be able
                             to sort should have a true value in this hash,
  -pre_nondb_columns      => [ARRAY] Columns to show left of database columns
                             in display table,
  -post_nondb_columns     => [ARRAY] Columns to show right of database columns
                             in display table,
     (Note: Since no data from the database will be present for
      -{pre,post}_nondb_columns columns, you should define
      -columndata_closures for each column you list)
  -optional_header        => Optional HTML header to display just above search
                             result display table,
  -optional_footer        => Optional HTML footer to display just below search
                             result display table,
  -href_extra_vars        => Extra CGI params to append to column sorting and
                             navigation links in search result display table.
                             May be either a HASHREF or a literal string
                             containing key/values to append.  If a key in the
                             HASHREF has an undef value, will take the value
                             from an existing CGI param on request named the
                             same as key.
  -action_uri             => HTTP URI of script this is running under
                             (default: SCRIPT_NAME environment variable),
  -max_results_per_page   => Maximum number of database records to display on a
                             single page of search result display table
                             (default: 20)
  -show_total_numresults  => Show total number of records found by most recent
                             search, with First/Last page navigation links
                             (default: true)
  -columndata_closures    => {HASH} of (CODE): Reference to a hash containing a
                             code reference for each column which should be
                             passed through before displaying in result table.
                             Each closure will be passed 3 arguments:
                              $searchobj (this CGI::Widget::DBI::Search object),
                              $row (the current row from the result set)
                              $color (the current background color of this row)
                             and is (currently) expected to return an HTML table
                             cell (e.g. "<td>blah</td>")
Universal options
  -no_persistent_object   => Inform object that we are not running under a
                             persistent object framework (eg. Apache::Session):
                             disable all features which enhance performance
                             under a persistence framework, and enable features
                             necessary for smooth operation without persistence
                             (default: true)


PRIVATE METHODS

_set_defaults()

Sets necessary object variables from defaults in package constants, if not already set. Called from search() method.

_set_display_defaults()

Sets object variables for displaying search results. Called from display_results() method.


METHODS

default_fetchrow_closure()

This is the default -fetchrow_closure that will be called for each row returned by a search. It can be called by an overridden -fetchrow_closure to selectively modify desired fields.

search([ $where_clause, $bind_params, $clobber ])

Perform the search: runs the database query, and stores the matched results in an object variable: 'results'.

Optional parameters $where_clause and $bind_params will override object variables -where_clause and -bind_params. If $clobber is true, search results from a previous execution will be deleted before running new search.

get_num_results()

Executes a SELECT COUNT() query with the current search parameters and stores result in object variable: 'numresults'. Has no effect unless -show_total_numresults object variable is true. Th is used for displaying total number of results found, and is necessary to provide a last-page link to skip to the end of the search results.

pagesort_results($col, $reverse)

Sorts a single page of results by column $col. Reorders object variable 'results' based on sort column $col and boolean $reverse parameters.

(note: method currently unused)

display_results([ $disp_cols ])

Displays an HTML table of data values stored in object variable 'results' (retrieved from the most recent call to search() method). Optional variable $disp_cols overrides object variable -display_columns.

generate_nav_links()

Returns four URIs for navigating through search results: $prevlink, $nextlink, $firstlink, $lastlink

display_pager_links($startat, $pagetotal, $maxpagesize, $searchtotal, $prevlink, $nextlink, $firstlink, $lastlink, $showtotal)

Returns an HTML table containing navigation links for first, previous, next, and last pages of result set. This method is called from display_results() and should be treated as a protected method.

parameters: $startat page of results on which to start $pagetotal number of items on *this* page $maxpagesize size of page: maximum number of items to show per page $searchtotal total number of items returned by search $prevlink HTML href link to previous page of results $nextlink HTML href link to next page of results $firstlink HTML href link to first page of results $lastlink HTML href link to last page of results $showtotal boolean to toggle whether to show total number of results along with range on current page


AUTHOR

Adi Fairbank <adi@adiraj.org>


COPYRIGHT

Copyright (c) 2004-2008 - Adi Fairbank

This software, the CGI::Widget::DBI::Search Perl module, is copyright Adi Fairbank.


COPYLEFT (LICENSE)

This module is free software; you can redistribute it and/or modify it under the terms of either:

  a) the GNU General Public License as published by the Free Software
     Foundation; either version 1, or (at your option) any later version,
  or
  b) the "Artistic License" which comes with this module.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the Artistic License for more details.

You should have received a copy of the Artistic License with this module, in the file ARTISTIC; if not, the following URL references a copy of it (as of June 8, 2003):

  http://www.perl.com/language/misc/Artistic.html

You should have received a copy of the GNU General Public License along with this program, in the file GPL; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA; or try the following URL which references a copy of it (as of June 8, 2003):

  http://www.fsf.org/licenses/gpl.html


LAST MODIFIED

Jan 31, 2008