Ubuntu Manpage: CGI::Test::Form - Querying interface to CGI form widgets

Provided by: libcgi-test-perl_1.111-2_all

NAME

       CGI::Test::Form - Querying interface to CGI form widgets

SYNOPSIS

        my $form = $page->forms->[0];       # first form in CGI::Test::Page

        #
        # Querying interface, to access form widgets
        #

        my @buttons = $form->button_list;   # ->buttons would give list ref
        my $radio_listref = $form->radios;  # ->radios_list would give list

        my $passwd_widget = $form->input_by_name("password");
        my ($login, $passwd) = $form->input_by_name(qw(login password));

        my @menus = $form->widgets_matching(sub { $_[0]->is_menu });
        my @menus = $form->menu_list;       # same as line above

        my $rg = $form->radio_groups;       # a CGI::Test::Form::Group or undef

        #
        # <FORM> attributes, as defined by HTML 4.0
        #

        my $encoding = $form->enctype;
        my $action = $form->action;
        my $method = $form->method;
        my $name = $form->name;
        my $accept = $form->accept;
        my $accept_charset = $form->accept_charset;

        #
        # Miscellaneous
        #

        # Low-level, direct calls normally not needed
        $form->reset;
        my $new_page = $form->submit;

        # Very low-level access
        my $html_tree = $form->tree;        # HTML::Element form tree
        my $page = $form->page;             # Page containing this form

        #
        # Garbage collection -- needed to break circular references
        #

        $form->delete;

DESCRIPTION

       The "CGI::Test::Form" class provides an interface to the content of the CGI forms.  Instances are
       automatically created by "CGI::Test" when it analyzes an HTML output from a GET/POST request and
       encounters such beasts.

       This class is really the basis of the "CGI::Test" testing abilities: it provides the necessary routines
       to query the CGI widgets present in the form: buttons, input areas, menus, etc...  Queries can be made by
       type, and by name.  There is also an interface to specifically access groupped widgets like checkboxes
       and radio buttons.

       All widgets returned by the queries are polymorphic objects, heirs of "CGI::Test::Form::Widget".  If the
       querying interface can be compared to the human eye, enabling you to locate a particular graphical item
       on the browser screen, the widget interface can be compared to the mouse and keyboard, allowing you to
       interact with the located graphical components.  Please refer to CGI::Test::Form::Widget for interaction
       details.

       Apart from the widget querying interface, this class also offers a few services to other "CGI::Test"
       components, like handling of reset and submit actions, which need not be used directly in practice.

       Finally, it provides inspection of the <FORM> tag attributes (encoding type, action, etc...) and, if you
       really need it, to the HTML tree of the all <FORM> content.  This interface is based on the
       "HTML::Element" class, which represents a tree node.  The tree is shared with other "CGI::Test"
       components, it is not a private copy.  See HTML::Element if you are not already familiar with it.

       If memory is a problem, you must be aware that circular references are used almost everywhere within
       "CGI::Test".  Because Perl's garbage collector cannot reclaim objects that are part of such a reference
       loop, you must explicitely call the delete method on "CGI::Test::Form".  Simply forgetting about the
       reference to that object is not enough.  Don't bother with it if your regression test scripts die
       quickly.

INTERFACE

The interface is mostly a querying interface. Most of the routines return widget objects, via lists or
list references. See CGI::Test::Form::Widget for details about the interface provided by widget objects,
and the classification.

The order of the widgets returned lists is the same as the order the widgets appear in the HTML
representation.

Type Querying Interface
There are two groups or routines: one group returns expanded lists, the other returns list references.
They are listed in the table below.

The Item Polymorphic Type column refers to the polymorphic dynamic type of items held within the list:
each item is guaranteed to at least be of that type, but can be a descendant. Types are listed in the
abridged form, and you have to prepend the string "CGI::Test::Form::" in front of them to get the real
type.

Expanded List List Reference Item Polymorphic Type
------------- -------------- ----------------------
button_list buttons Widget::Button
checkbox_list checkboxes Widget::Box::Check
hidden_list hidden Widget::Hidden
input_list inputs Widget::Input
menu_list menus Widget::Menu
radio_list radios Widget::Box::Radio
submit_list submits Widget::Button::Submit
widget_list widgets Widget

For instance:

my @widgets = @{$form->widgets}; # heavy style
my @widgets = $form->widget_list; # light style

A given widget may appear in several lists, i.e.the above do not form a partition over the widget set.
For instance, a submit button would appear in the "widget_list" (which lists all widgets), in the
"button_list" and in the "submit_list".

Name Querying Interface
Those routine take a name or a list of names, and return the widgets whose parameter name is exactly the
given name (string comparison). You may query all widgets, or a particular class, like all buttons, or
all input fields.

There are two groups of routines:

• One group allows for multiple name queries, and returns a list of widgets, one entry for each listed
name. Some widgets like radio buttons may have multiple instances bearing the same name, and in that
case only one is returned. When querying for one name, you are allowed to use scalar context:

my @hidden = $form->hidden_by_name("foo", "bar");
my ($context) = $form->hidden_by_name("context");
my $context = $form->hidden_by_name("context");

When no widget (of that particular type) bearing the requested name is found, "undef" is returned for
that particular slot, so don't blindly make method calls on each returned value.

We shall call that group of query routines the by-name group.

• The other group allows for a single name query, but returns a list of all the widgets (of some
particular type when not querying the whole widget list) bearing that name.

my @hidden = $form->hidden_named("foo");

Don't assume that only radios and checkboxes can have multiple instances bearing the same name.

We shall call that group of query routines the all-named group.

The available routines are listed in the table below. Note that by-name queries are singular, because
there is at most one returned widget per name asked, whereas all-named queries are plural, where
possible.

The Item Polymorphic Type column refers to the polymorphic dynamic type of items held within the list:
each defined item is guaranteed to at least be of that type, but can be a descendant. Types are listed
in the abridged form, and you have to prepend the string "CGI::Test::Form::" in front of them to get the
real type.

By-Name Queries All-Named Queries Item Polymorphic Type
---------------- ----------------- ----------------------
button_by_name buttons_named Widget::Button
checkbox_by_name checkboxes_named Widget::Box::Check
hidden_by_name hidden_named Widget::Hidden
input_by_name inputs_named Widget::Input
menu_by_name menus_named Widget::Menu
radio_by_name radios_named Widget::Box::Radio
submit_by_name submits_named Widget::Button::Submit
widget_by_name widgets_named Widget

Match Querying Interface
This is a general interface, which invokes a matching callback on each widget of a particular category.
The signature of the matching routines is:

my @matching = $form->widgets_matching(sub {code}, $arg);

and the callback is invoked as:

callback($widget, $arg);

A widget is kept if, and only if, the callback returns true. Be sure to write your callback so that is
only uses calls that apply to the particular widget. When you know you're matching on menu widgets, you
can call menu-specific features, but should you use that same callback for buttons, you would get a
runtime error.

Each matching routine returns a list of matching widgets. Using the $arg parameter is optional, and
should be avoided unless you have no other choice, so as to be as stateless as possible.

The following table lists the available matching routines, along with the polymorphic widget type to be
expected in the callback. As usual, you must prepend the string "CGI::Test::Form::" to get the real
type.

Matching Routine Item Polymorphic Type
------------------- ---------------------
buttons_matching Widget::Button
checkboxes_matching Widget::Box::Check
hidden_matching Widget::Hidden
inputs_matching Widget::Input
menus_matching Widget::Menu
radios_matching Widget::Box::Radio
submits_matching Widget::Button::Submit
widgets_matching Widget

For instance:

my @menus = $form->widgets_matching(sub { $_[0]->is_menu });
my @color = $form->widgets_matching(
sub { $_[0]->is_menu && $_[0]->name eq "color" }
);

is an inefficient way of saying:

my @menus = $form->menu_list;
my @color = $form->menus_matching(sub { $_[0]->name eq "color" });

and the latter can further be rewritten as:

my @color = $form->menus_named("color");

Form Interface
This provides an interface to get at the attributes of the <FORM> tag. For instance:

my $enctype = $form->enctype;

to get at the encoding type of that particular form. The following attributes are available:

accept
accept_charset
action
enctype
method
name

as defined by HTML 4.0.

Group Querying Interface
There are two kinds of widgets that are architecturally groupped, meaning more that one instance of that
widget can bear the same name: radio buttons and checkboxes (although you may have a single standalone
checkbox).

All radio buttons and checkboxes defined in a form are automatically inserted into a group of their own,
which is an instance of the "CGI::Test::Form::Group" class. This class contains all the defined groups
for a particular kind. The routines:

checkbox_groups
radio_groups

give you access to the "CGI::Test::Form::Group" container. Both routines may return "undef" when there
is no checkbox or radio button in the form. See CGI::Test::Form::Group for its querying interface.

Memory Cleanup
You must call the delete method to break the circular references if you wish to dispose of the object.

Internal Interface
The following routines are available internally:

reset
Reset the form state, restoring all the controls to the value they had upon entry.

submit
Submit the form, returning a "CGI::Test::Page" reply.

AUTHORS

       The original author is Raphael Manfredi.

       Steven Hilton was long time maintainer of this module.

       Current maintainer is Alexander Tokarev <tokarev@cpan.org>.

NAME

SYNOPSIS

DESCRIPTION

INTERFACE

AUTHORS

SEE ALSO