1Padre::DB::Plugin(3) User Contributed Perl Documentation Padre::DB::Plugin(3)
2
6 Padre::DB::Plugin - Padre::DB class for the plugin table
7
9 TO BE COMPLETED
10
12 base
13 # Returns 'Padre::DB'
14 my $namespace = Padre::DB::Plugin->base;
15 Normally you will only need to work directly with a table class, and
17 only with one ORLite package.
18 However, if for some reason you need to work with multiple ORLite
20 packages at the same time without hardcoding the root namespace all the
21 time, you can determine the root namespace from an object or table
22 class with the "base" method.
23 table
25 # Returns 'plugin'
26 print Padre::DB::Plugin->table;
27 While you should not need the name of table for any simple operations,
29 from time to time you may need it programatically. If you do need it,
30 you can use the "table" method to get the table name.
31 load
33 my $object = Padre::DB::Plugin->load( $name );
34 If your table has single column primary key, a "load" method will be
36 generated in the class. If there is no primary key, the method is not
37 created.
38 The "load" method provides a shortcut mechanism for fetching a single
40 object based on the value of the primary key. However it should only be
41 used for cases where your code trusts the record to already exists.
42 It returns a "Padre::DB::Plugin" object, or throws an exception if the
44 object does not exist.
45 select
47 # Get all objects in list context
48 my @list = Padre::DB::Plugin->select;
49 # Get a subset of objects in scalar context
51 my $array_ref = Padre::DB::Plugin->select(
52 'where name > ? order by name',
53 1000,
54 );
55 The "select" method executes a typical SQL "SELECT" query on the plugin
57 table.
58 It takes an optional argument of a SQL phrase to be added after the
60 "FROM plugin" section of the query, followed by variables to be bound
61 to the placeholders in the SQL phrase. Any SQL that is compatible with
62 SQLite can be used in the parameter.
63 Returns a list of Padre::DB::Plugin objects when called in list
65 context, or a reference to an "ARRAY" of Padre::DB::Plugin objects when
66 called in scalar context.
67 Throws an exception on error, typically directly from the DBI layer.
69 iterate
71 Padre::DB::Plugin->iterate( sub {
72 print $_->name . "\n";
73 } );
74 The "iterate" method enables the processing of large tables one record
76 at a time without loading having to them all into memory in advance.
77 This plays well to the strength of SQLite, allowing it to do the work
79 of loading arbitrarily large stream of records from disk while
80 retaining the full power of Perl when processing the records.
81 The last argument to "iterate" must be a subroutine reference that will
83 be called for each element in the list, with the object provided in the
84 topic variable $_.
85 This makes the "iterate" code fragment above functionally equivalent to
87 the following, except with an O(1) memory cost instead of O(n).
88 foreach ( Padre::DB::Plugin->select ) {
90 print $_->name . "\n";
91 }
92 You can filter the list via SQL in the same way you can with "select".
94 Padre::DB::Plugin->iterate(
96 'order by ?', 'name',
97 sub {
98 print $_->name . "\n";
99 }
100 );
101 You can also use it in raw form from the root namespace for better
103 control. Using this form also allows for the use of arbitrarily
104 complex queries, including joins. Instead of being objects, rows are
105 provided as "ARRAY" references when used in this form.
106 Padre::DB->iterate(
108 'select name from plugin order by name',
109 sub {
110 print $_->[0] . "\n";
111 }
112 );
113 count
115 # How many objects are in the table
116 my $rows = Padre::DB::Plugin->count;
117 # How many objects
119 my $small = Padre::DB::Plugin->count(
120 'where name > ?',
121 1000,
122 );
123 The "count" method executes a "SELECT COUNT(*)" query on the plugin
125 table.
126 It takes an optional argument of a SQL phrase to be added after the
128 "FROM plugin" section of the query, followed by variables to be bound
129 to the placeholders in the SQL phrase. Any SQL that is compatible with
130 SQLite can be used in the parameter.
131 Returns the number of objects that match the condition.
133 Throws an exception on error, typically directly from the DBI layer.
135 new
137 TO BE COMPLETED
138 The "new" constructor is used to create a new abstract object that is
140 not (yet) written to the database.
141 Returns a new Padre::DB::Plugin object.
143 create
145 my $object = Padre::DB::Plugin->create(
146 name => 'value',
148 version => 'value',
150 enabled => 'value',
152 config => 'value',
154 );
156 The "create" constructor is a one-step combination of "new" and
158 "insert" that takes the column parameters, creates a new
159 Padre::DB::Plugin object, inserts the appropriate row into the plugin
160 table, and then returns the object.
161 If the primary key column "name" is not provided to the constructor (or
163 it is false) the object returned will have "name" set to the new unique
164 identifier.
165 Returns a new plugin object, or throws an exception on error, typically
167 from the DBI layer.
168 insert
170 $object->insert;
171 The "insert" method commits a new object (created with the "new"
173 method) into the database.
174 If a the primary key column "name" is not provided to the constructor
176 (or it is false) the object returned will have "name" set to the new
177 unique identifier.
178 Returns the object itself as a convenience, or throws an exception on
180 error, typically from the DBI layer.
181 delete
183 # Delete a single instantiated object
184 $object->delete;
185 # Delete multiple rows from the plugin table
187 Padre::DB::Plugin->delete('where name > ?', 1000);
188 The "delete" method can be used in a class form and an instance form.
190 When used on an existing Padre::DB::Plugin instance, the "delete"
192 method removes that specific instance from the "plugin", leaving the
193 object intact for you to deal with post-delete actions as you wish.
194 When used as a class method, it takes a compulsory argument of a SQL
196 phrase to be added after the "DELETE FROM plugin" section of the query,
197 followed by variables to be bound to the placeholders in the SQL
198 phrase. Any SQL that is compatible with SQLite can be used in the
199 parameter.
200 Returns true on success or throws an exception on error, or if you
202 attempt to call delete without a SQL condition phrase.
203 truncate
205 # Delete all records in the plugin table
206 Padre::DB::Plugin->truncate;
207 To prevent the common and extremely dangerous error case where deletion
209 is called accidentally without providing a condition, the use of the
210 "delete" method without a specific condition is forbidden.
211 Instead, the distinct method "truncate" is provided to delete all
213 records in a table with specific intent.
214 Returns true, or throws an exception on error.
216
218 name
219 if ( $object->name ) {
220 print "Object has been inserted\n";
221 } else {
222 print "Object has not been inserted\n";
223 }
224 Returns true, or throws an exception on error.
226 REMAINING ACCESSORS TO BE COMPLETED
228
230 The plugin table was originally created with the following SQL command.
231 CREATE TABLE plugin (
233 name VARCHAR(255) PRIMARY KEY,
234 version VARCHAR(255),
235 enabled BOOLEAN,
236 config TEXT
237 )
238
240 Padre::DB::Plugin is part of the Padre::DB API.
241 See the documentation for Padre::DB for more information.
243
245 Adam Kennedy <adamk@cpan.org>
246
248 Copyright 2008-2011 The Padre development team as listed in Padre.pm.
249 This program is free software; you can redistribute it and/or modify it
251 under the same terms as Perl itself.
252 The full text of the license can be found in the LICENSE file included
254 with this module.
255perl v5.28.1 2011-08-16 Padre::DB::Plugin(3)