Module: Netzke::Core::Composition

Extended by:
ActiveSupport::Concern
Included in:
Base
Defined in:
lib/netzke/core/composition.rb

Overview

Any Netzke component can define child components, which can either be statically nested in the compound layout (e.g. as different regions of the 'border' layout), or dynamically loaded at a request (as is the advanced search panel in Basepack::GridPanel, for example).

Defining a component

You can define a child component by calling the component class method which normally requires a block:

component :users do |c|
  c.klass = GridPanel
  c.model = "User"
  c.title = "Users"
end

If no configuration is required, and the component's class name can be derived from its name, then the block can be omitted, e.g.:

component :user_grid

which is equivalent to:

component :user_grid do |c|
  c.klass = UserGrid
end

Overriding a component

When overriding a component, the `super` method should be called, with the configuration object passed to it as parameter:

component :users do |c|
  super(c)
  c.title = "Modified Title"
end

Referring to components in layouts

A child component can be referred in the layout by using symbols:

component :users do |c|
  c.title = "A Netzke component"
end

def configure(c)
  super
  c.items = [
    { xtype: :panel, title: "Simple Ext panel" },
    :users # a Netzke component
  ]
end

If an extra (layout) configuration should be provided, a component can be referred to by using the component key in the configuration hash (this can be useful when overriding a layout of a child component):

component :tab_one # ...
component :tab_two # ...

def configure(c)
  super
  c.items = [
    {component: :tab_one, title: "One"},
    {component: :tab_two, title: "Two"}
  ]
end

Lazily vs eagerly loaded components

By default, if a component is not used in the layout, it is lazily loaded, which means that the code for this component is not loaded in the browser until the moment the component gets dynamically loaded by the JavaScript method `netzkeLoadComponent` (see Javascript). Referring a component in the layout (the `items` property) automatically makes it eagerly loaded. Sometimes it's desired to eagerly load a component without using it directly in the layout (an example can be a window that we need to render instantly without requesting the server). In this case an option `eager_loading` can be set to true:

component :eagerly_loaded_window do |c|
  c.klass = SomeWindowComponent
  c.eager_loading = true
end

Dynamic component loading

Child components can be dynamically loaded by using client class' netzkeLoadComponent method (see javascript/ext.js for inline documentation):

Excluded components

You can make a child component inavailable for dynamic loading by using the excluded option. When an excluded component is used in the layout, it will be skipped. This can be used for authorization.

Instance Method Summary (collapse)

Instance Method Details

- (Object) component_instance(name, options = {})

Instantiates a child component by its name. params can contain:

[client_config] a config hash passed from the client class
[item_id] overridden item_id (used in case of multi-instance loading)


128
129
130
131
132
133
134
135
136
137
138
# File 'lib/netzke/core/composition.rb', line 128

def component_instance(name, options = {})
  return nil if !respond_to?("#{name}_component")

  cfg = ComponentConfig.new(name, self)
  cfg.client_config = options[:client_config] || {}
  cfg.item_id = options[:item_id]
  cfg.js_id = options[:js_id]
  send("#{name}_component", cfg)
  cfg.set_defaults!
  cfg.klass.new(cfg, self)
end

- (Array<Symbol>) components_in_config



120
121
122
# File 'lib/netzke/core/composition.rb', line 120

def components_in_config
  @components_in_config || (normalize_config || true) && @components_in_config
end

- (Array<Class>) dependency_classes



141
142
143
144
145
146
147
148
149
150
# File 'lib/netzke/core/composition.rb', line 141

def dependency_classes
  res = []

  eagerly_loaded_components.keys.each do |aggr|
    res += component_instance(aggr).dependency_classes
  end

  res += self.class.netzke_ancestors
  res.uniq
end

- (Hash) eagerly_loaded_components



115
116
117
# File 'lib/netzke/core/composition.rb', line 115

def eagerly_loaded_components
  @eagerly_loaded_components ||= components.select{|k,v| components_in_config.include?(k) || v[:eager_loading]}
end

- (Object) extend_item(item)



152
153
154
155
156
# File 'lib/netzke/core/composition.rb', line 152

def extend_item(item)
  item = detect_and_normalize(:component, item)
  @components_in_config << item[:netzke_component] if include_component?(item)
  super item
end