Provided by: libjifty-dbi-perl_0.77-1_all 
NAME
Jifty::DBI::Schema - Use a simple syntax to describe a Jifty table.
SYNOPSIS
package MyApp::Model::Page;
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
# ... your columns here ...
};
DESCRIPTION
Each Jifty Application::Model::Class module describes a record class for a Jifty
application. Each "column" statement sets out the name and attributes used to describe
the column in a backend database, in user interfaces, and other contexts. For example:
column content =>
type is 'text',
label is 'Content',
render as 'textarea';
defines a column called "content" that is of type "text". It will be rendered with the
label "Content" (note the capital) and as a "textarea" in a HTML form.
Jifty::DBI::Schema builds a Jifty::DBI::Column. That class defines other attributes for
database structure that are not exposed directly here. One example of this is the
"refers_to" method used to create associations between classes.
It re-exports "defer" and "lazy" from Scalar::Defer, for setting parameter fields that
must be recomputed at request-time:
column name =>
default is defer { Jifty->web->current_user->name };
See Scalar::Defer for more information about "defer".
filter_die
FUNCTIONS
All these functions are exported. However, if you use the "schema" helper function, they
will be unimported at the end of the block passed to "schema".
schema
Takes a block with schema declarations. Unimports all helper functions after executing
the code block. Usually used at "BEGIN" time via this idiom:
use Jifty::DBI::Record schema { ... };
If your application subclasses "::Record", then write this instead:
use MyApp::Record schema { ... };
column
DEPRECATED. This method of defining columns will not work anymore. Please use the
"schema {}" method documented above.
merge_params HASHREF HASHREF
Takes two hashrefs. Merges them together and returns the merged hashref.
- Empty fields in subclasses don't override nonempty fields in superclass anymore.
- Arrays don't merge; e.g. if parent class's valid_values is [1,2,3,4], and
subclass's valid_values() is [1,2], they don't somehow become [1,2,3,4,1,2].
BUG: This should either be a private routine or factored out into Jifty::Util
register_types
references
Indicates that the column references an object or a collection of objects in another
class. You may refer to either a class that inherits from Jifty::Record by a primary key
in that class or to a class that inherits from Jifty::Collection.
referencing a record
Correct usage is "references Application::Model::OtherClass by 'column_name'", where
Application::Model::OtherClass is a valid Jifty model, subclass of Jifty::Record, and
'column_name' is a distinct column of OtherClass. You can omit "by 'column_name'" and the
column name 'id' will be used.
At this moment you must specify type of the column your self to match type of the column
you refer to.
You can name a column as combination of 'name' and 'by', for example:
column user_name => references App::Model::User by 'name', type is 'varchar(64)';
Then user, user_name and respective setters will be generated. user method will return
object, user_name will return actual value. Note that if you're using some magic on load
for user records then to get real name of loaded record you should use
"$record->user->name" instead.
In the above case name of the column in the DB will be 'user_name'. If you don't like
suffixes like '_id', '_name' and other in the DB then you can name column without suffix,
for example:
column user => references App::Model::User by 'name', type is 'varchar(64)';
In this case name of the column in the DB will be 'user', accessors will be the same as in
above example.
referencing a collection
Correct usage is "references Application::Model::OtherCollection by 'column_name'", where
Application::Model::OtherCollection is a valid Jifty model, subclass of Jifty::Collection,
and 'column_name' is a column of records in OtherCollection. In this case "by
'column_name'" is not optional.
Columns that refers to a collection are virtual and can be changed. So such columns in a
model doesn't create real columns in the DB, but instead it's way to name collection of
records that refer to this records.
example
Simple model with users and multiple phone records per user:
package TestApp::Model::User;
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
column name => type is 'varchar(18)';
...
column phones => references TestApp::Model::PhoneCollection by 'user';
};
package TestApp::Model::Phone;
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
column user => references TestApp::Model::User by 'id',
is mandatory;
column type => ...;
column value => ...;
};
From a user record you get his phones and do something:
my $phones = $user->phones;
while ( my $phone = $phones->next ) {
...
}
From a phone record you can get its owner or change it:
my $user_object = $phone->user;
my $user_id = $phone->user_id;
$phone->set_user( $new_owner_object );
$phone->set_user( 123 ); # using id
$phone->set_user_id( 123 ); # the same, but only using id
refers_to
Synonym for "references".
by
Helper for "references". Used to specify what column name should be used in the
referenced model. See the documentation for "references".
type
type passed to our database abstraction layer, which should resolve it to a database-
specific type. Correct usage is "type is 'text'".
Currently type is passed directly to the database. There is no intermediary mapping from
abstract type names to database specific types.
The impact of this is that not all column types are portable between databases. For
example blobs have different names between mysql and postgres.
default
Give a default value for the column. Correct usage is "default is 'foo'".
literal
Used for default values, to connote that they should not be quoted before being supplied
as the default value for the column. Correct usage is "default is literal 'now()'".
validator
Defines a subroutine which returns a true value only for valid values this column can
have. Correct usage is "validator is \&foo".
immutable
States that this column is not writable. This is useful for properties that are set at
creation time but not modifiable thereafter, like 'created by'. Correct usage is "is
immutable".
unreadable
States that this column is not directly readable by the application using
"$record->column"; this is useful for password columns and the like. The data is still
accessible via "$record->_value('')". Correct usage is "is unreadable".
max_length
Sets a maximum max_length to store in the database; values longer than this are truncated
before being inserted into the database, using Jifty::DBI::Filter::Truncate. Note that
this is in bytes, not characters. Correct usage is "max_length is 42".
mandatory
Mark as a required column. May be used for generating user interfaces. Correct usage is
"is mandatory".
not_null
Same as "mandatory". This is deprecated. Correct usage would be "is not_null".
autocompleted
Mark as an autocompleted column. May be used for generating user interfaces. Correct
usage is "is autocompleted".
distinct
Declares that a column should only have distinct values. This currently is implemented
via database queries prior to updates and creates instead of constraints on the database
columns themselves. This is because there is no support for distinct columns implemented
in DBIx::DBSchema at this time. Correct usage is "is distinct".
virtual
Used to declare that a column references a collection, which hides it from many parts of
Jifty. You probably do not want to set this manually, use "references" instead.
computed
Declares that a column is not backed by an actual column in the database, but is instead
computed on-the-fly using a method written by the application author. Such columns cannot
(yet) be used in searching, sorting, and so on, only inspected on an individual record.
sort_order
Declares an integer sort value for this column. By default, Jifty will sort columns in the
order they are defined.
order
Alias for "sort_order".
input_filters
Sets a list of input filters on the data. Correct usage is "input_filters are
'Jifty::DBI::Filter::DateTime'". See Jifty::DBI::Filter.
output_filters
Sets a list of output filters on the data. Correct usage is "output_filters are
'Jifty::DBI::Filter::DateTime'". See Jifty::DBI::Filter. You usually don't need to set
this, as the output filters default to the input filters in reverse order.
filters
Sets a list of filters on the data. These are applied when reading and writing to the
database. Correct usage is "filters are 'Jifty::DBI::Filter::DateTime'". See
Jifty::DBI::Filter. In actuality, this is the exact same as "input_filters", since output
filters default to the input filters, reversed.
since
What application version this column was last changed. Correct usage is "since '0.1.5'".
till
The version after this column was supported. The column is not available in the version
named, but would have been in the version immediately prior.
Correct usage is "till '0.2.5'". This indicates that the column is not available in
version 0.2.5, but was available in 0.2.4. The value specified for "since" must be less
than this version.
valid_values
A list of valid values for this column. Jifty will use this to automatically construct a
validator for you. This list may also be used to generate the user interface. Correct
usage is "valid_values are qw/foo bar baz/".
If you want to display different values than are stored in the DB you can pass a list of
hashrefs, each containing two keys, display and value.
valid_values are
{ display => 'Blue', value => 'blue' },
{ display => 'Red', value => 'red' }
valid
Alias for "valid_values".
label
Designates a human-readable label for the column, for use in user interfaces. Correct
usage is "label is 'Your foo value'".
hints
A sentence or two to display in long-form user interfaces about what might go in this
column. Correct usage is "hints is 'Used by the frobnicator to do strange things'".
display_length
The displayed length of form fields. Though you may be able to fit 500 characters in the
field, you would not want to display an HTML form with a size 500 input box.
render_as
Used in user interface generation to know how to render the column.
The values for this attribute are the same as the names of the modules under
Jifty::Web::Form::Field, i.e.
• Button
• Checkbox
• Combobox
• Date
• Hidden
• InlineButton
• Password
• Radio
• Select
• Textarea
• Upload
• Unrendered
You may also use the same names with the initial character in lowercase.
The "Unrendered" may seem counter-intuitive, but is there to allow for internal fields
that should not actually be displayed.
If these don't meet your needs, you can write your own subclass of
Jifty::Web::Form::Field. See the documentation for that module.
render
Alias for "render_as".
indexed
An index will be built on this column Correct usage is "is indexed"
EXAMPLE
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COPYRIGHT & LICENSE
This program is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.