NAME
CGI::Application::Search - Base class for CGI::App Swish-e site engines
SYNOPSIS
package My::Search;
use base 'CGI::Application::Search';
sub cgiapp_init {
my $self = shift;
$self->param(
'SWISHE_INDEX' => 'my-swishe.index',
'TEMPLATE' => 'search_results.tmpl',
);
}
sub cgiapp_prerun {
my $self = shift;
my $query = $self->query;
# let the user turn context highlighting off
$self->param('HIGHLIGHT' => 0) if $query->param('highlight_off');
# let the user change which property is used in the sort
my $sort_by = $query->param('sort_by');
$self->param('SORT_BY' => $sort_by) if $sort_by;
}
1;
DESCRIPTION
A CGI::Application based control module that uses Swish-e API in perl
(<http://swish-e.org>) to to perform searches on a swish-e index of
documents.
Features
* Sub-Classable. Unlike the Perl examples that come with swish-e, this
is not a script, and can be customized without modifiying the original
so that several sites may share the same underlying code.
* Uses CGI::Application::Plugin::AnyTemplate to allow flexibility in
template engine choice (HTML::Template, Template-Toolkit or Petal).
* Built-in templates to use out of box or as examples for your own
templates
* HiLighted search results
* HiLighted pages linked from search results
* AJAX results sent to page without need of a page reload
* AJAX powered 'auto-suggest' to give the user list of choices available
for search
TUTORIAL
If this is your first time using Swish-e (or you think you need a
refresher) or if you want step-by-step instructions on how to use the
AJAX capabilities of this module, then please see the "Tutorial".
RUN_MODES
The start_mode is show_search.
show_search()
This method will load the template pointed to by the TEMPLATE param
(falling back to a default internal template if none is specified) and
display it to the user. It will 'associate' this template with $self so
that any parameters in $self->param() are also accessible to the
template. It will also use HTML::FillInForm to fill in the search form
with the previously selected parameters (unless it's a
'non-page-refresh' AJAX search).
perform_search()
This is where the meat of the searching is performed. We create a
SWISH::API object on the SWISHE_INDEX and create the query for the
search based on the value of the *keywords* parameter in CGI and any
other EXTRA_PROPERTIES. The search is executed and if HIGHLIGHT is true
we will use Search::Tools::HiLiter to highlight it and then format the
results, only showing PER_PAGE number of elements A paging list is also
shown for navigating through the results. Then we will return to the
show_search() method for displaying everything.
highlight_remote_page
This run mode will fetch a remote page (with either a relative, or
absolute URL using the "url" Query param) and highlight the keywords
used in the search on that page (the "keywords" Query param) using the
HIGHLIGHT_TAG, HIGHLIGHT_CLASS or HIGHLIGHT_COLORS options. This run
mode is best used in the links of the search results listing.
<a href="?rm=highlight_remote_page;url=http%3A%2F%2Fexample.com%2Fabout_us%2Findex.html;keywords=Us">about us</a>
highlight_local_page
This run mode will fetch a local page (only allowing relative files
based in the DOCUMENT_ROOT config var and the path using the "path"
Query param) and highlight the keywords used in the search on that page
(the "keywords" Query param) using the HIGHLIGHT_TAG, HIGHLIGHT_CLASS or
HIGHLIGHT_COLORS options. This run mode is best used in the links of the
search results listing.
<a href="?rm=highlight_local_page;path=%2Fabout_us%2Findex.html;keywords=Us">about us</a>
suggestions
This run mode will return an AJAX listing of words that should be
suggested to the user for the words that they have typed so far. It uses
the "suggested_words()" method to actually choose which words to send
back.
OTHER METHODS
Most of the time you will not need to call the methods that are
implemented in this module. But in some cases customizing the templates
is not enought. If so, it might be prudent to override or extend these
methods in your derived class.
new()
We simply override and extend the CGI::Application new() to setup our
defaults.
setup()
Here's were we setup our run modes. If you override this method, make
sure you also call it in your base class
sub setup {
my $self = shift;
# do your thing
...
$self->SUPER::setup();
}
generate_search_query($keywords)
This method is used to generate the query for swish-e from the $keywords
(by default the 'keywords' CGI parameter), as well as any
EXTRA_PROPERTIES that are present.
If you wish to generate your own search query then you should override
this method. This is common if you need to have access/authorization
control that will need to be taken into account for your search. (eg,
anything under /protected can't be seen by someone not logged in).
Please see the swish-e documentation on the exact syntax for the query.
suggested_words($word)
This object method is used by the AUTO_SUGGEST flag to return the words
that should be suggested to the user after they have typed a $word. It
returns an array reference of those words.
By default it will just look for words in the AUTO_SUGGEST_FILE that
begin with $word. If you need more performance or flexibility (eg,
storing your words in a database and querying for them) you are
encouraged to override this method.
CONFIGURATION
There are several configuration parameters that you can set at any time
(using "param()" in your cgiapp_init, or PARAMS hash in new()) before
the run mode is called that will affect the search and display of the
results. They are:
SWISHE_INDEX
This is the swishe index used for the searches. The default is
'data/swish-e.index'. You will probably set this every time.
AJAX
This is a boolean indicating whether or not a non-page-refresh AJAX
search will be permitted.
Please see the "Tutorial" for more information on how to use the AJAX
capabilities of this module.
TEMPLATE
The name of the search interface template. Default templates are
included with this distribution and will be used if you don't specify
one. Which default template is used depends on which TEMPLATE_TYPE you
are using (*HTMLTemplate* or *TemplateToolkit*) and whether or not the
AJAX flag is true.
These sample templates are installed with the module, or you can view
them by looking under the templates/ directory of the source
distribution (*.tar.gz*).
Please see "TEMPLATE USAGE" for more information on which variables are
passed into your template.
TEMPLATE_TYPE
This module uses CGI::Application::Plugin::AnyTemplate to allow
flexibility in choosing which templating system to use for your search.
This works especially well when you are trying to integrate the Search
into an existing app with an existing templating structure.
This value is passed to the "$self->template->config()" method as the
"default_type". By default it is 'HTMLTemplate'. Please see
CGI::Application::Plugin::AnyTemplate for more options.
If you want more control of configuration for the template the it would
probably best be done by subclassing CGI::Application::Search and
passing your desired params to "$self->template->config".
PER_PAGE
How many search result items to display per page. The default is 10.
HIGHLIGHT
Boolean indicating whether or not we should highlight the description
given to the templates. The default is true.
HIGHLIGHT_TAG
The HTML tag used to surround the highlighted context. The default is
"strong".
HIGHLIGHT_CLASS
The class attribute of the HIGHLIGHT_TAG HTML tag. This is useful when
you want to dictacte the style through a CSS style sheet. If given, this
value will override that of HIGHLIGHT_COLORS. It has no value by
default.
HIGHLIGHT_COLORS
This is an array ref of acceptable HTML colors. If provided, it will
highlight each matching word/phrase in an alternating style. For
instance, if given 2 colors, every other highlighted phrase would be a
different color. By default it is an empty array.
EXTRA_PROPERTIES
This is an array ref of extra properties used in the search. By default,
the module will only use the value of the 'keywords' parameter coming in
the CGI query. If anything is provided as an extra property then it will
be added to the query used in the search.
An example: You have some of you pages designated into categories. You
want the user to have the option of narrowing his results by category.
You add the word 'category' to the 'EXTRA_PROPERTIES' list and then you
add a 'category' form element that the user has the option of giving a
value to your search form. If the user gives that element a value, then
it will be seen and applied to the search. This will also only work if
you have the 'category' element defined for your documents (see *SWISH-E
Configuration* and 'MetaNames' in the swish-e.org SWISH-CONF
documentation).
By default, this list is empty.
EXTRA_RANGE_PROPERTIES
This is almost exactly like the "EXTRA_PROPERTIES" above except that
instead of searching for the given properties as simple strings, we will
use a range. Since ranges need to values, if you're searching for the
"foo" property, then you need to have a "foo_start" and a "foo_end"
value coming from the query. So if "foo" is in your
"EXTRA_RANGE_PROPERTIES" and you have a CGI query string like this:
?foo_start=123&foo_end=234
Then we will a generate a Swish-E query that looks something like this:
-L foo 123 234
DESCRIPTION_LENGTH
This is the maximum length for the context (in chars) that is displayed
for each search result. The default is 250 characters.
DESCRIPTION_CONTEXT
This is the number of words on either side of the searched for words and
phrases (keywords) that will be displayed as part of the description. If
this is 0, then the entire description will be displayed. The default is
0.
NOTE: This directive will cause Search to use Text::Context, which can
be slow and CPU intensive at times. These computations may prove to be
too much for some servers (eg, a shared hosting environment).
AUTO_SUGGEST
If true, then this will allow the broswer to give suggestions to the
user as they type. To use this, you must either use the
AUTO_SUGGEST_FILE configuration option, or override the
"suggested_words()" method.
You template must also have the appropriate JavaScript code. Please see
the "Tutorial" for more details.
AUTO_SUGGEST_FILE
The name of the file where the suggested words are stored. These words
should be in alphabetical order with one word per line.
AUTO_SUGGEST_CACHE
A boolean indicating whether or not the results of the AUTO_SUGGEST_FILE
should be cached in memory or not. This will save repeated file accesses
when used in a persistant environment.
AUTO_SUGGEST_LIMIT
An integer count of the most suggestions to show the user at a time.
This is useful when you don't want to overwhelm the end user and take
over their screen with all of your helpful suggestions.
DOCUMENT_ROOT
This is the root directory to use when looking for files when using the
"highlight_local_page" run mode.
SORT_BY
This is a string used by Swish-e to sort the results. The string is a
space separated list of valid document properties. Each property may
contain a qualifier (either "asc" or "desc") that sets the direction of
the sort. Leave it alone and Swish-e will sort by "swishrank" in
descending order. But say you wanted to reverse that for some reason.
You could specify a "SORT_BY" of
swishrank asc
FIF_DEFAULTS
A hash reference of extra parameters that are passed to HTML::FillInForm
when it does it's business with the forms. This is useful to telling
HTML::FillInForm to skip certain forms or form elements.
TEMPLATE USAGE
Sample templates are included with this distribution. These sample
templates are installed with the module, or you can view them by looking
under the templates/ directory of the source distribution (*.tar.gz*).
Please feel free to copy and change them in what ever way you see fit.
To help give you more information to display (or not display, depending
on your preference) the following variables are available for your
templates:
Global Tmpl Vars
These variables are available throughout the templates and contain
information related to the search as a whole:
* ajax A boolean indicating whether or not this search is an AJAX
search or not. You can use this flag to exclude everything but
your search results in your template.
* url The URL of this application. This is useful if you want to use
the same templates in multiple applications, especially if you
are using the AJAX capabilities since they require the URL to
submit to.
* searched
A boolean indicating whether or not a search was performed.
* keywords
The exact string that was recieved by the server from the input
named 'keywords'
* elapsed_time
A string representing the number of seconds that the search
took. This will be a floating point number with a precision of
3.
* hits This is an array of hashs (TMPL_LOOP in H::T) that contains one
entry for each result returned (for the current page). Each
entry contains the following keys:
reccount
The "swishreccount" property of the results as indexed
by SWISH-E
rank The rank to the result as given by SWISH-E (the
"swishrank" property)
title The "swishtitle" property of the results as indexed by
SWISH-E
path The "swishdocpath" property of the results as indexed by
SWISH-E
last_modified
The "swishlastmodified" property of the results as
indexed by SWISH-E and then formatted using
Time::Piece's "strftime()" method with a format string
of "%B %d, %Y".
size The "swishdocsize" property of the results as indexed by
SWISH-E and then formatted with Number::Format's
"format_bytes()" method.
description
The "swishdescription" property of the results as
indexed by SWISH-E. If HIGHLIGHT is true, then this
description will also have search terms highlighted and
will only be, at most, DESCRIPTION_LENGTH characters
long.
* pages This is an array of hashes (TMPL_LOOP in H::T) that contains
paging information for the results. It contains the following
keys:
current A boolean indicating whether or not this iteration is
the current page or not.
page_num
The integer number of the page.
* first_page
This is a boolean indicating whether or not this page of the
results is the first or not.
* last_page
This is a boolean indicating whether or not this page of the
results is the last or not.
* prev_page
The integer number of the previous page. Will be 0 if there is
no previous page.
* next_page
The integer number of the next page. Will be 0 if there is no
next page.
* start_num
This is the number of the first result on the current page
* stop_num
This is the number of the last result on the current page
* total_entries
The total number of results in their search, not the total
number shown on the page.
OTHER NOTES
* If at any time prior to the execution of the 'perform_search' run
mode you set the "$self->param('results')" parameter, a search will
not be performed. Instead those results are returned. This is
helpful when you decide in the "cgiapp_init" stage that this user
does not have permissions to perform the desired search.
* You must use the *StoreDescription* setting in your Swish-e
configuration file. If you don't you'll get an error when
C::A::Search tries to retrieve a description for each hit.
AUTHOR
Michael Peters <mpeters@plusthree.com>
Thanks to Plus Three, LP (http://www.plusthree.com) for sponsoring my
work on this module.
CONTRIBUTORS
Sam Tregar <sam@tregar.com>
Mark Stosberg <mark@summersault.com>
Eric Folley <efolley@plusthree.com>