Package TWiki::Form::FieldDefinition
Base class of all field definition classes.
Type-specific classes are derived from this class to define specific
per-type behaviours. This class also provides default behaviours for when
a specific type cannot be loaded.
Construct a new
FieldDefinition. Parameters are passed in a hash. See
Form.pm for how it is called. Subclasses should pass
@_ on to this class.
Break circular references.
Is the field type editable? Labels aren't, for example. Subclasses may need
to redefine this.
Is the field type multi-valued (i.e. does it store multiple values)?
Subclasses may need to redefine this.
Is this field type mergeable using a conventional text merge?
Is this field mandatory (required)?
$web
- the web containing the topic being edited
$topic
- the topic being edited
Render the field for editing. Returns two chunks of HTML; the
$col0html
is appended to the HTML for the first column in the
form table, and the
$col1html
is used as the content of the second column.
Construct a list of the CSS classes for the form field. Adds additional
class specifiers related to the attributes of the field e.g mandatory.
Pass it a list of the other classnames you want on the field.
Try and get a sensible default value for the field from the
values stored in the form definition. The result should be
a value string.
Some subclasses may not support the definition of defaults in
the form definition. In that case this method should return
undef
.
Render the form in
$meta
as a set of hidden fields.
Given a CGI
$query
, a
$meta
object, and an array of
$old
field entries,
then populate the $meta with a row for this field definition, taking the
content from the query if it's there, otherwise from $old or failing that,
from the default defined for the type. Refuses to update mandatory fields
that have an empty value.
Return $bValid true if the value in $meta was updated (either from the
query or from a default in the form.
Return $bPresent true if a value was present in the query (even it was undef)
Render the field for display, under the control of $attrs.
The following vars in $format are expanded:
$title - title of the form field
$value - expanded to the
protected value of the form field
The value is protected by TWiki::Render::protectFormFieldValue.