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Man Pages


Manual Reference Pages  -  JIFTY::DBI::SCHEMA (3)

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NAME

Jifty::DBI::Schema - Use a simple syntax to describe a Jifty table.

CONTENTS

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 dont override nonempty fields in superclass anymore.
    - Arrays dont merge; e.g. if parent classs valid_values is [1,2,3,4], and
      subclasss valid_values() is [1,2], they dont 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 <B>bytesB>, not <B>charactersB>. 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 <B>andB> 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.
o Button
o Checkbox
o Combobox
o Date
o Hidden
o InlineButton
o Password
o Radio
o Select
o Textarea
o Upload
o 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.
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perl v5.20.3 JIFTY::DBI::SCHEMA (3) 2014-05-29

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