Reaction::UI::ViewPort - Page layout building block


  # Create a new ViewPort:
  # $stack isa Reaction::UI::FocusStack object
  my $vp = $stack->push_viewport('Reaction::UI::ViewPort', layout => 'xhtml');

  # Fetch ViewPort higher up the stack (further out)
  my $outer = $vp->outer();

  # Fetch ViewPort lower down (further in)
  my $inner = $vp->inner();

  # Create a named tangent stack for this ViewPort
  my $substack = $vp->create_tangent('name');

  # Retrieve a tangent stack for this ViewPort
  my $substack = $vp->forcus_tangent('name');

  # Get the names of all the tangent stacks for this ViewPort
  my @names = $vp->focus_tangents();

  # Fetch all the tangent stacks for this ViewPort
  # This is called by apply_events
  my $stacks = $vp->child_event_sinks();

  ### The following methods are all called automatically when using
  ### Reaction::UI::Controller(s)
  # Resolve current events with this ViewPort
  $vp->apply_events($ctx, $param_hash);

  # Apply current events to all tangent stacks
  # This is called by apply_events
  $vp->apply_child_events($ctx, $params_hash);

  # Apply current events to this ViewPort
  # This is called by apply_events
  $vp->apply_our_events($ctx, $params_hash);


A ViewPort describes part of a page, it can be a field, a form or an entire page. ViewPorts are created on a Reaction::UI::FocusStack, usually belonging to a controller or another ViewPort. Each ViewPort knows it's own position in the stack it is in, as well as the stack containing it.

Each ViewPort has a specific location in the heirarchy of viewports making up a page. The hierarchy is determined as follows: The first ViewPort in a stack is labeled 0, the second is 1 and so on. If a ViewPort is in a named tangent, it's location will contain the name of the tangent in it's location.

For example, the first ViewPort in the 'left' tangent of the main ViewPort has location 0.left.0.

Several ViewPort attributes are set by "push_viewport" in Reaction::UI::FocusStack when new ViewPorts are created, these are as follows:


The outer attribute is set to the previous ViewPort in the stack when creating a ViewPort, if the ViewPort is the first in the stack, it will be undef.


The inner attribute is set to the next ViewPort down in the stack when it is created, if this is the last ViewPort in the stack, it will be undef.


The focus_stack attribute is set to the Reaction::UI::FocusStack object that created the ViewPort.


The ctx attribute will be passed automatically when using "push_viewport" in Reaction::UI::Controller to create a ViewPort in the base stack of a controller. When creating tangent stacks, you may have to pass it in yourself.


The layout attribute can either be specifically passed when calling push_viewport, or it will be determined using the last part of the ViewPorts classname.


This read-only hashref attribute will pass all it's keys as variables to the layout at render time. They should be accessible from both the layout templates and the widget, if applicable, through the %_ hash.

    $controller->push_viewport(VPName, layout => 'foo', layout_args => { bar => 'bar'});
    $_{bar} #in widget
    [% bar %] in template

This is generally used by more specialised ViewPorts such as the ListView or Action. It can be either a space separated list of column names, or an arrayref of column names.



Arguments: none

Fetch the ViewPort outside this one in the page hierarchy.


Arguments: none

Fetch the ViewPort inside this one in the page hierarchy.


Arguments: $tangent_name

Create a new named Reaction::UI::FocusStack inside this ViewPort. The created FocusStack is returned.


Arguments: $tangent_name

Fetch a named FocusStack from this ViewPort.


Arguments: none

Returns a list of names of all the known tangents in this ViewPort.


Return the Reaction::UI::FocusStack object that this ViewPort is in.


Arguments: $ctx, $params_hashref

This method is called by the FocusStack object to resolve all events for the ViewPort.


Arguments: $ctx, $params_hashref

Resolve the given events for all the tangents of this ViewPort. Called by apply_events.


Arguments: $ctx, $events

Resolve the given events that match the location of this ViewPort. Called by apply_events.


Arguments: $events

Actually call the event handlers for this ViewPort. Called by apply_our_events. By default this will do nothing, subclass ViewPort and implement accept_events.


Arguments: none

Implement this method in a subclass and return a list of events that your ViewPort is accepting.


Arguments: $name

Create an id for the given event name and this ViewPort. Generally returns the location and the name, joined with a colon.


Arguments: $spec, $items

Sorts the given list of items such that the ones that also appear in the spec are at the beginning. This is called by Reaction::UI::ViewPort::Action and Reaction::UI::ViewPort::ListView, and gets passed column_order as the spec argument.


See Reaction::Class for authors.


See Reaction::Class for the license.