jsFind - generate index for full text search engine in JavaScript
use jsFind; my $t = new jsFind(B => 4); my $f = 1; foreach my $k (qw{minima ut dolorem sapiente voluptatem}) { $t->B_search(Key => $k, Data => { "path" => { t => "word $k", f => $f }, }, Insert => 1, Append => 1, ); }
This module can be used to create index files for jsFind, powerful tool for adding a search engine to a CDROM archive or catalog without requiring the user to install anything.
Main difference between this module and scripts delivered with jsFind are:
You don't need to use swish-e to create index
you can programatically (and incrementaly) create index for jsFind
you can create more than one index and search them using same search.html page
search.html
You can also examine examples which come as tests with this module, for example t/04words.t or t/10homer.t.
t/04words.t
t/10homer.t
jsFind search engine was written by Shawn Garbett from eLucid Software. The search engine itself is a small piece of JavaScript (1.2 with level 2 DOM). It is easily customizable to fit into a current set of HTML. This JavaScript searches an XML index dataset for the appropriate links, and can filter and sort the results.
JavaScript code distributed with this module is based on version 0.0.3 which was current when this module development started. Various changes where done on JavaScript code to fix bugs, add features and remove warnings. For complete list see Changes file which comes with distribution.
Changes
This module has been tested using html/test.html with following browsers:
html/test.html
using DOM 2 document.implementation.createDocument
document.implementation.createDocument
using ActiveX Microsoft.XMLDOM or MSXML2.DOMDocument
Microsoft.XMLDOM
MSXML2.DOMDocument
using experimental iframe implementation which is much slower than other methods.
If searching doesn't work for your combination of operating system and browser, please open html/test.html file and wait a while. It will search sample file included with distribution and report results. Reports with included test debugging are welcomed.
jsFind is mode implementing methods which you, the user, are going to use to create indexes.
jsFind
Create new tree. Arguments are B which is maximum numbers of keys in each node and optional Root node. Each root node may have child nodes.
B
Root
All nodes are objects from jsFind::Node.
jsFind::Node
my $t = new jsFind(B => 4);
Search, insert, append or replace data in B-Tree
$t->B_search( Key => 'key value', Data => { "path" => { "t" => "title of document", "f" => 99, }, }, Insert => 1, Append => 1, );
Semantics:
If key not found, insert it iff Insert argument is present.
Insert
If key is found, replace existing data iff Replace argument is present or add new datum to existing iff Append argument is present.
Replace
Append
Return B (maximum number of keys)
my $max_size = $t->B;
Returns root node
my $root = $t->root;
Returns if node is overfull
if ($node->node_overfull) { something }
Returns your tree as formatted string.
my $text = $root->to_string;
Mostly usefull for debugging as output leaves much to be desired.
Create Graphviz graph of your tree
my $dot_graph = $root->to_dot;
Create xml index files for jsFind. This should be called after your B-Tree has been filled with data.
$root->to_jsfind( dir => '/full/path/to/index/dir/', data_codepage => 'ISO-8859-2', index_codepage => 'UTF-8', output_filter => sub { my $t = shift || return; $t =~ s/è/e/; } );
All options except dir are optional.
dir
Returns number of nodes in created tree.
Options:
Full path to directory for index (which will be created if needed).
If your imput data isn't in ISO-8859-1 encoding, you will have to specify this option.
ISO-8859-1
If your index encoding is not UTF-8 use this option.
UTF-8
If you are not using supplied JavaScript search code, or your browser is terribly broken and thinks that index shouldn't be in UTF-8 encoding, use this option to specify encoding for created XML index.
this is just draft of documentation for option which is not implemented!
Code ref to sub which can do modifications on resulting XML file for node. Encoding of this data will be in index_codepage and you have to take care not to break XML structure. Calling xmllint on your result index (like t/90xmllint.t does in this distribution) is a good idea after using this option.
t/90xmllint.t
This option is also right place to plug in unaccenting function using Text::Unaccent.
This is internal function to recode charset.
It will also try to decode entities in data using HTML::Entities.
Each node has k key-data pairs, with B <= k <= 2B, and each has k+1 subnodes, which might be null.
k
2B
k+1
The node is a blessed reference to a list with three elements:
($keylist, $datalist, $subnodelist)
each is a reference to a list list.
The null node is represented by a blessed reference to an empty list.
Create New node
my $node = new jsFind::Node ($keylist, $datalist, $subnodelist);
You can also mit argument list to create empty node.
my $empty_node = new jsFind::Node;
Locate key in node using linear search. This should probably be replaced by binary search for better performance.
my ($found, $index) = $node->locate_key($key, $cmp_coderef);
Argument $cmp_coderef is optional reference to custom comparison operator.
$cmp_coderef
Returns (1, $index) if $key[$index] eq $key.
Returns (0, $index) if key could be found in $subnode[$index].
In scalar context, just returns 1 or 0.
Creates new empty node
$node = $root->emptynode; $new_node = $node->emptynode;
Test if node is empty
if ($node->is_empty) { something }
Return $ith key from node
$i
my $key = $node->key($i);
Return $ith data from node
my $data = $node->data($i);
Set key data pair for $ith element in node
$node->kdp_replace($i, "key value" => { "data key 1" => "data value 1", "data key 2" => "data value 2", };
Insert key/data pair in tree
$node->kdp_insert("key value" => "data value");
No return value.
Adds new data keys and values to $ith element in node
$node->kdp_append($i, "key value" => { "added data key" => "added data value", };
Set new or return existing subnode
# return 4th subnode my $my_node = $node->subnode(4); # create new subnode 5 from $my_node $node->subnode(5, $my_node);
Test if node is leaf
if ($node->is_leaf) { something }
Return number of keys in the node
my $nr = $node->size;
Split node into two halves so that keys 0 .. $n-1 are in one node and keys $n+1 ... $size are in the other.
0 .. $n-1
$n+1 ... $size
my ($left_node, $right_node, $kdp) = $node->halves($n);
Dumps tree as string
my $str = $root->to_string;
Recursivly walk nodes of tree
Escape <, >, & and ", and to produce valid XML
Convert number to base x (used for jsFind index filenames).
my $n = $tree->base_x(50);
Create jsFind xml files
my $nr=$tree->to_jsfind('/path/to/index','0');
Returns number of elements created
jsFind web site http://www.elucidsoft.net/projects/jsfind/
B-Trees in perl web site http://perl.plover.com/BTree/
This module web site http://www.rot13.org/~dpavlin/jsFind.html
Mark-Jonson Dominus <mjd@pobox.com> wrote BTree.pm which was base for this module
BTree.pm
Shawn P. Garbett <shawn@elucidsoft.net> wrote jsFind
Dobrica Pavlinusic <dpavlin@rot13.org> wrote this module
Copyright (C) 2004 by Dobrica Pavlinusic
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. 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 the GNU General Public License for more details.
To install jsFind, copy and paste the appropriate command in to your terminal.
cpanm
cpanm jsFind
CPAN shell
perl -MCPAN -e shell install jsFind
For more information on module installation, please visit the detailed CPAN module installation guide.