NAME

DBIx::HTMLView::Fld - Base class for field and relation classes

SYNOPSIS

$fld=$post->fld('testf');
print $fld->view_html;

DESCRIPTION

These objects are used to represent the fields and relations of a table inside the and the DBIx::HTMLView::Table object as well as the data contained in those fields and relations in the DBIx::HTMLView::Post objects.

This is the base class of all field classes such as DBIx::HTMLView::Text DBIx::HTMLView::Str and DBIx::HTMLView::Int as well as the relations such as DBIx::HTMLView::N2N.

METHODS

$fld=DBIx::HTMLView::Fld->($name, $data) =head2 $fld=DBIx::HTMLView::Fld->new($name, $val, $tab)

The only time you create this kind of objects is when you create the DBIx::HTMLView::Table objects of the top level description of the databse (se DBIx::HTMLView::DB). And in that case it is the first version of the constructor you use preferable through the shortcuts in DBIx::HTMLView. $name is a string naming the relation or field while $data is a hashref with parameters specific to the field or relation kind used. There are a few parameters that are common though:

sql_size - The size to be used to store this in the database, eg the value 100 in the sql type definition CHAR(100). sql_type - Allows you to overide the database specific default type to use for a fld. If this is defined it will be used as sql type for this fld. fmt - A string specifying how this Fld should be viewed by default. It is the fmt string that will be used by view_fmt if no other are specified, or if the one specified does not excist. The format of this string depends on the type of Fld se the docs to the view_fmt methods of the diffrent Fld subclasses for info on it. fmt_* - You can give each Fld any number of custom fmts used to view this fld in diffrent contexts. There are a few special one: fmt_view_html, fmt_edit_html, fmt_view_text that are tied to the method calls view_html, edit_html, view_text respectivly (eg the method call view_html is the same as view_fmt('view_html'))

The second version of the constructor is used by the DBIx::HTMLView::Table class when it creates copies of its flds, gives them their data $val and places them in a post. $tab is the DBIx::HTMLView::Table object the fld belongs to.

For fields data ($val) is specified as a string or as the first item of an array referenced to by $val. Relations are represented as a reference to an array of the id's of the posts being related to.

$fld->name

Returns the name of the fld.

$fld->data($key)

Returns the value of $key set from the $data hashref in the new method. It dies if the data was not set.

$fld->got_data($key)

Returns true if the value of $key was set in the $data hashref in the new method.

$fld->set_tab($tab)

Used by DBIx::HTMLView::Table to inform the fld of which table it belongs to. All fld belongs to either a Table or a Post.

$fld->set_post($post)

Used by DBIx::HTMLView::Post to inform the fld pf which post it belongs to. All fld belongs to either a Table or a Post.

$fld->tab

Return the DBIx::HTMLView::Table object this fld belongs to.

$fld->db

Return the DBIx::HTMLView::Db object this fld belongs to.

$fld->post

Returns the DBIx::HTMLView::Post object this fld belongs to.

VIRTUAL METHODS

Those methods are not defined in this class, but are suposed to be defined in all fld subclasses.

$fld->view_fmt($fmt_name,$fmt)

Returns a string used to display the contents (value) of the fld. Usually this is just the value of the fld, but for more complex Fld, like relations, $fmt_name can be used to specify which fmt that should be used (the diffrent fmts are defined in the constructor, se the $fld->new method). If the $fmt param is defined it will be used as the fmt string insteda of looking up a default one.

$fld->view_html

Returns a html string used to display the contents (value) of the fld.

$fld->edit_html

Returns a string that can be placed inside an html <form> section used to edit this field or relation. It will be some sort of input tag with the same name as the fld.

$fld->sql_data($sel)

Called if this fld is used in the selection string in a DBIx::HTMLView::Selection object $sel. It is supposed to add apropriate data to the object using $sel->add_fld and $sel->add_tab (se the DBIx::HTMLView::Selection manpage for details) and return the string to represent it in the where clause (it will usualy be the name of the field itself).

$fld->view_text

Returns a text string used to view the contents (value) of the fld (this method is not yet implemented for all fld classes).

$fld->del($id)

Is called when a post with id $id is deleted. This is to allow the relations of this post to clean out the data that is placed in other tabels. The actual post will be removed from the table after all fld object del methods has been called.

$fld->field_name

The name of the sql field in the main table representing this fld. For a N2N relation it will be undefined as it is represented in a separate table and not in the main one. For fields it will ofcourse be the name of the field.

$fld->name_vals

This medthod is called whenever the data of a post are updated in the actual database or a new post is added. It returns an array of hashes containing the two keys name and val. Where the value of the name keys are the names of database fields that are supposed to be set to the values of the val keys. e.g. return ( {'name' => 'Color', 'value' => 'Red'}, {'name' => 'Size', 'value' => 'XXL'} );

This is the method where relations are supposed to update all secondary tabels (eg the tables used to represent the actuall relations).

$fld->sql_create

Will send the nesesery SQL commands to create this fld in database and return the sql type (if any) of this field to be included in the CREATE clause for the main table. That is normal fields will only return their type while relations will create it's link table.

$fld->fmt($kind)

Returns the "fmt_$kind" param as passed to the constructor (se new method for info). If that one does not excist the default one "fmt" is used. If thatone isn't specified either the default fmt '$val' is returned.

To allow subclasses to provide more decent defaults the default_fmt($kind) method is called if "fmt_$kind" is not defined. If it returns undef this method carries on as described above, otherwise the return value of default_fmt is returned. Then default_fmt is called again if there was no "fmt" param speciefied, but this time with $kind undefined.

The default implementation here is ofcourse to always return undef, that will give the behaviour described in the first paragraph here.

A replacment default_fmt should never return undef but instead execute it's supreclass version of it and return it's value if it dosn't want to override the specified kind.

$fld->default_fmt($kind)

Used to allow subclasses to provide there own default fmts, se $fld->fmt($kind).

$fld->view_text =head2 $fld->view_html =head2 $fld->edit_text

For backwards compatibility those are linked to view_fmt('view_text'), view_fmt('view_html'), view_fmt('edit:html'), respectivly.