Maypole::Model::CDBI::UserrContributed Perl DocMaypole::Model::CDBI::AsForm(3)NAME
Maypole::Model:CDBI::AsForm - Produce HTML form elements for database
columns
SYNOPSIS
package Music::CD;
use Maypole::Model::CDBI::AsForm;
use base 'Class::DBI';
use CGI;
...
sub create_or_edit {
my $self = shift;
my %cgi_field = $self->to_cgi;
return start_form,
(map { "<b>$_</b>: ". $cgi_field{$_}->as_HTML." <br>" }
$class->Columns),
end_form;
}
. . .
# Somewhere else in a Maypole application about beer...
$beer->to_field('brewery', 'textfield', {
name => 'brewery_id', value => $beer->brewery,
# however, no need to set value since $beer is object
});
# Rate a beer
$beer->to_field(rating => select => {
items => [1 , 2, 3, 4, 5],
});
# Select a Brewery to visit in the UK
Brewery->to_field(brewery_id => {
items => [ Brewery->search_like(location => 'UK') ],
});
# Make a select for a boolean field
$Pub->to_field('open' , { items => [ {'Open' => 1, 'Closed' => 0 } ] });
$beer->to_field('brewery', {
selected => $beer->brewery, # again not necessary since caller is obj.
});
$beer->to_field('brewery', 'link_hidden', {r => $r, uri => 'www.maypole.perl.org/brewery/view/'.$beer->brewery});
# an html link that is also a hidden input to the object. R is required to
# make the uri unless you pass a uri
#####################################################
# Templates Usage
<form ..>
...
<label>
<span class="field"> [% classmetadata.colnames.$col %] : </span>
[% object.to_field(col).as_XML %]
</label>
. . .
<label>
<span class="field"> Brewery : </span>
[% object.to_field('brewery', { selected => 23} ).as_XML %]
</label>
. . .
</form>
#####################################################
# Advanced Usage
# has_many select
package Job;
__PACKAGE__->has_a('job_employer' => 'Employer');
__PACKAGE__->has_a('contact' => 'Contact')
package Contact;
__PACKAGE__->has_a('cont_employer' => 'Employer');
__PACKAGE__->has_many('jobs' => 'Job',
{ join => { job_employer => 'cont_employer' },
constraint => { 'finshed' => 0 },
order_by => "created ASC",
}
);
package Employer;
__PACKAGE__->has_many('jobs' => 'Job',);
__PACKAGE__->has_many('contacts' => 'Contact',
order_by => 'name DESC',
);
# Choose some jobs to add to a contact (has multiple attribute).
my $job_sel = Contact->to_field('jobs'); # Uses constraint and order by
# Choose a job from $contact->jobs
my $job_sel = $contact->to_field('jobs');
1;
DESCRIPTION
This module helps to generate HTML forms for creating new database rows
or editing existing rows. It maps column names in a database table to
HTML form elements which fit the schema. Large text fields are turned
into textareas, and fields with a has-a relationship to other
"Class::DBI" tables are turned into select drop-downs populated with
objects from the joined class.
ARGUMENTS HASH
This provides a convenient way to tweak AsForm's behavior in
exceptional or not so exceptional instances. Below describes the
arguments hash and example usages.
$beer->to_field($col, $how, $args);
$beer->to_field($col, $args);
Not all _to_* methods pay attention to all arguments. For example,
'_to_textfield' does not look in $args->{'items'} at all.
name -- the name the element will have , this trumps the derived name.
$beer->to_field('brewery', 'readonly', {
name => 'brewery_id'
});
value -- the initial value the element will have, trumps derived value
$beer->to_field('brewery', 'textfield', {
name => 'brewery_id', value => $beer->brewery,
# however, no need to set value since $beer is object
});
items -- array of items generally used to make select box options
Can be array of objects, hashes, arrays, or strings, or just a
hash.
# Rate a beer
$beer->to_field(rating => select => {
items => [1 , 2, 3, 4, 5],
});
# Select a Brewery to visit in the UK
Brewery->to_field(brewery_id => {
items => [ Brewery->search_like(location => 'UK') ],
});
# Make a select for a boolean field
$Pub->to_field('open' , { items => [ {'Open' => 1, 'Closed' => 0 } ] });
selected -- something representing which item is selected in a select
box
$beer->to_field('brewery', {
selected => $beer->brewery, # again not necessary since caller is obj.
});
Can be an simple scalar id, an object, or an array of either
class -- the class for which the input being made for field pertains
to.
This in almost always derived in cases where it may be difficult to
derive, --
# Select beers to serve on handpump
Pub->to_field(handpumps => select => { class =>
'Beer', order_by => 'name ASC', multiple => 1, });
column_type -- a string representing column type
$pub->to_field('open', 'bool_select', {
column_type => "bool('Closed', 'Open'),
});
column_nullable -- flag saying if column is nullable or not
Generally this can be set to get or not get a null/empty option
added to a select box. AsForm attempts to call
"$class->column_nullable" to set this and it defaults to true if
there is no shuch method.
$beer->to_field('brewery', { column_nullable => 1 });
r or request -- the Mapyole request object
uri -- uri for a link , used in methods such as _to_link_hidden
$beer->to_field('brewery', 'link_hidden',
{r => $r, uri => 'www.maypole.perl.org/brewery/view/'.$beer->brewery});
# an html link that is also a hidden input to the object. R is required to
# make the uri unless you pass a uri
order_by, constraint, join
These are used in making select boxes. order_by is a simple order
by clause and constraint and join are hashes used to limit the rows
selected. The difference is that join uses methods of the object
and constraint uses static values. You can also specify these in
the relationship definitions. See the relationships documentation
of how to set arbitrayr meta info.
BeerDB::LondonBeer->has_a('brewery', 'BeerDB::Brewery',
order_by => 'brewery_name ASC',
constraint => {location => 'London'},
'join' => {'brewery_tablecolumn => 'beer_obj_column'},
);
no_hidden_constraints --
Tell AsForm not to make hidden inputs for relationship constraints.
It does this sometimes when making foreign inputs. However, i
think it should not do this and that the FromCGI 's _create_related
method should do it.
to_cgi
$self->to_cgi([@columns, $args]);
This returns a hash mapping all the column names to HTML::Element
objects representing form widgets. It takes two opitonal arguments --
a list of columns and a hashref of hashes of arguments for each column.
If called with an object like for editing, the inputs will have the
object's values.
$self->to_cgi(); # uses $self->columns; # most used
$self->to_cgi(qw/brewery style rating/); # sometimes
# and on rare occassions this is desireable if you have a lot of fields
# and dont want to call to_field a bunch of times just to tweak one or
# two of them.
$self->to_cgi(@cols, {brewery => {
how => 'textfield' # too big for select
},
style => {
column_nullable => 0,
how => 'select',
items => ['Ale', 'Lager']
}
});
to_field($field [, $how][, $args])
This maps an individual column to a form element. The "how" argument
can be used to force the field type into any you want. All that you
need is a method named "_to_$how" in your class. Your class inherits
many from AsForm already.
If "how" is specified but the class cannot call the method it maps to,
then AsForm will issue a warning and the default input will be made.
You can write your own "_to_$how" methods and AsForm comes with many.
See "HOW Methods". You can also pass this argument in $args->{how}.
search_inputs
my $cgi = $class->search_inputs ([$args]); # optional $args
Returns hash or hashref of search inputs elements for a class making
sure the inputs are empty of any initial values. You can specify what
columns you want inputs for in $args->{columns} or by the method
"search_columns". The default is "display_columns". If you want to te
search on columns in related classes you can do that by specifying a
one element hashref in place of the column name where the key is the
related "column" (has_a or has_many method for example) and the value
is a list ref of columns to search on in the related class.
Example:
sub BeerDB::Beer::search_columns { return ( 'name' , 'rating',
{ brewery => [ 'name', 'location'] } );
}
# Now foreign inputs are made for Brewery name and location and the
# there will be no name clashing and processing can be automated.
unselect_element
unselect any selected elements in a HTML::Element select list widget
_field_from_how($field, $how,$args)
Returns an input element based the "how" parameter or nothing at all.
Override at will.
_field_from_relationship($field, $args)
Returns an input based on the relationship associated with the field or
nothing. Override at will.
For has_a it will give select box
_field_from_column($field, $args)
Returns an input based on the column's characteristics, namely type, or
nothing. Override at will.
recognized arguments
selected => $object|$id,
name => $name,
value => $value,
where => SQL 'WHERE' clause,
order_by => SQL 'ORDER BY' clause,
constraint => hash of constraints to search
limit => SQL 'LIMIT' clause,
items => [ @items_of_same_type_to_select_from ],
class => $class_we_are_selecting_from
stringify => $stringify_coderef|$method_name
1. a select box out of a has_a or has_many related class. # For has_a the
default behavior is to make a select box of every element in # related
class and you choose one. #Or explicitly you can create one and pass
options like where and order BeerDB::Beer->to_field('brewery','select',
{where => "location = 'Germany'");
# For has_many the default is to get a multiple select box with all objects.
# If called as an object method, the objects existing ones will be selected.
Brewery::BeerDB->to_field('beers','select', {where => "rating > 5"});
2. a select box for objects of arbitrary class -- say BeerDB::Beer for fun.
# general BeerDB::Beer->to_field('', 'select', $options)
BeerDB::Beer->to_field('', 'select'); # Select box of all the rows in class
# with PK as ID, $Class->to_field() same.
BeerDB::Beer->to_field('','select',{ where => "rating > 3 AND class like 'Ale'", order_by => 'rating DESC, beer_id ASC' , limit => 10});
# specify exact where clause
3. If you already have a list of objects to select from --
BeerDB:;Beer->to_field($col, 'select' , {items => $objects});
# 3. a select box for arbitrary set of objects
# Pass array ref of objects as first arg rather than field
$any_class_or_obj->to_field([BeerDB::Beer->search(favorite => 1)],
'select',);
_to_enum_select
Returns a select box for the an enum column type.
_to_bool_select
Returns a "No/Yes" select box for a boolean column type.
_to_hidden($field, $args)
This makes a hidden html element input. It uses the "name" and "value"
arguments. If one or both are not there, it will look for an object in
"items->[0]" or the caller. Then it will use $field or the primary key
for name and the value of the column by the derived name.
_to_link_hidden($col, $args)
Makes a link with a hidden input with the id of $obj as the value and
name. Name defaults to the objects primary key. The object defaults to
self.
_to_foreign_inputs
Creates inputs for a foreign class, usually related to the calling
class or object. In names them so they do not clash with other names
and so they can be processed generically. See _rename_foreign_inputs
below and Maypole::Model::CDBI::FromCGI::classify_foreign_inputs.
Arguments this recognizes are :
related_meta -- if you have this, great, othervise it will determine or die
columns -- list of columns to make inputs for
request (r) -- TODO the Maypole request so we can see what action
_hash_selected
*Function* to make sense out of the "selected" argument which has
values of the options that should be selected by default when making a
select box. It can be in a number formats. This method returns a map
of which options to select with the values being the keys in the map (
{val1 => 1, val2 = 1} ).
Currently this method handles the following formats for the "selected"
argument and in the following ways
Object -- uses the id method to get the value
Scalar -- assumes it *is* the value
Array ref of objects -- same as Object
Arrays of data -- uses the 0th element in each
Hashes of data -- uses key named 'id'
_select_guts
Internal api method to make the actual select box form elements. the
data.
Items to make options out of can be
Hash, Array,
Array of CDBI objects.
Array of scalars ,
Array or Array refs with cols from class,
Array of hashes
_options_from_objects ( $objects, $args);
Private method to makes a options out of objects. It attempts to call
each objects stringify method specified in $args->{stringify} as the
content. Otherwise the default stringification prevails.
*Note only single primary keys supported
_to_checkbox
Makes a checkbox element -- TODO
_to_radio
Makes a radio button element -- TODO
_rename_foreign_input
_rename_foreign_input($html_el_or_hash_of_them); # changes made by
reference
Recursively renames the foreign inputs made by _to_foreign_inputs so
they can be processed generically. It uses foreign_input_delimiter.
So if an Employee is a Person who has_many Addresses and you call and
the method 'foreign_input_delimiter' returns '__AF__' then
Employee->to_field("person");
will get inputs for the Person as well as their Address (by default,
override _field_from_relationship to change logic) named like this:
person__AF__address__AF__street
person__AF__address__AF__city
person__AF__address__AF__state
person__AF__address__AF__zip
And the processor would know to create this address, put the address id
in person->{address} data slot, insert the person and put the person id
in the employee->{person} data slot and then insert the employee with
that data.
foreign_input_delimiter
This tells AsForm what to use to delmit forieign input names. This is
important to avoid name clashes as well as automating processing of
forms.
_box($value)
This functions computes the dimensions of a textarea based on the value
or the defaults.
CHANGES
1.0 15-07-2004 -- Initial version =head1 MAINTAINER
Maypole Developers
AUTHORS
Peter Speltz, Aaron Trevena
AUTHORS EMERITUS
Simon Cozens, Tony Bowden
TODO
Testing - lots
checkbox generalization
radio generalization
Make link_hidden use standard make_url stuff when it gets in Maypole
How do you tell AF --" I want a has_many select box for this every time so,
when you call "to_field($this_hasmany)" you get a select box
BUGS and QUERIES
Please direct all correspondence regarding this module to:
Maypole list.
COPYRIGHT AND LICENSE
Copyright 2003-2004 by Simon Cozens / Tony Bowden
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
Class::DBI, Class::DBI::FromCGI, HTML::Element.
perl v5.14.1 2007-05-18 Maypole::Model::CDBI::AsForm(3)
