Fixes #21634 - Allows modification of output fields

doc/commands_modification.md

@@ -0,0 +1,74 @@
+Modify an existing command
+-------------------------
+
+### Modification of output fields
+
+Each command (as well as each field) might have its own
+output definition. You can modify the output definition of existing
+command or a specific field of that command by following output
+definition interface:
+
+```ruby
+# Appends fields to the end.
+# Where:
+#   fields is one or more existing fields
+#   block is block of code with new fields
+append(fields) do
+  label
+  field
+  collection
+end
+# Inserts one or more fields.
+# Where:
+#   :mode is one of [:before, :after, :replace]
+#   :id is field's id or key. Field's label can be used if field does not
+# have id
+#   fields is one or more existing fields
+#   block is block of code with new fields
+insert(:mode, :id, fields) do
+  label
+  field
+  collection
+end
+# Returns output definition of the command or field specified with path.
+# Where:
+#   path = Array of :key or/and :id or/and 'label']
+at(path)
+# Returns field from current output definition.
+find_field(:id)
+# Deletes all fields from current output definition.
+clear
+```
+#### Examples
+```ruby
+# Append some fields to the end
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .at('Collection Field Label')
+                                   .append do
+                                     field :value3, _('Value 3')
+                                   end
+# Change field's label
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .at(:path)
+                                   .find_field(:id).label = _('New label')
+# Expand a field with new definition
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .at(['some', :path])
+                                   .insert(:replace, :not_container_field_id) do
+                                     field nil, _('Label with new fields'), Fields::Label, id: :now_container_field_id do
+                                       field :new_field1, _('New field 1')
+                                       field :new_field2, _('New field 2')
+                                     end
+                                   end
+# Insert a new field after specific field
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .at(['some', :path])
+                                   .insert(:after, :other_field_id, [Fields::Field.new(label: _('My field'), id: :my_field_id)])
+# Insert a new field before specific field
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .insert(:before, :other_field_id,
+                                   Fields::Field.new(label: _('My field'), id: :my_field_id))
+# Remove field
+HammerCLIForeman::Host::InfoCommand.output_definition
+                                   .insert(:replace, :field_id) do; end
+```

doc/developer_docs.md

@@ -8,6 +8,7 @@ before creating hammer specific plugins.
 Contents:
  - [Writing a plugin](writing_a_plugin.md#writing-your-own-hammer-plugin)
  - [Creating commands](creating_commands.md#create-your-first-command)
+ - [Commands modification](commands_modification.md#modify-an-existing-command)
  - [Option builders](option_builders.md#option-builders)
  - [Creating ApiPie commands](creating_apipie_commands.md#creating-commands-for-restful-api-with-apipie)
  - [Development tips](development_tips.md#development-tips)

lib/hammer_cli/output/definition.rb

@@ -1,21 +1,68 @@
 module HammerCLI::Output
-
   class Definition
-
     attr_accessor :fields
 
     def initialize
       @fields = []
     end
 
-    def append(fields)
+    def append(fields = nil, &block)
+      fields = [fields].compact unless fields.is_a?(Array)
       @fields += fields
+      return @fields unless block_given?
+      dsl = Dsl.new
+      dsl.build(&block)
+      @fields += dsl.fields
+    end
+
+    def find_field(field_id)
+      @fields[field_index(field_id)]
+    end
+
+    def insert(mode, field_id, fields = nil, &block)
+      index = field_index(field_id)
+      index += 1 if mode == :after
+      definition = self.class.new
+      definition.append(fields, &block)
+      insert_fields(index, definition.fields, with_remove: mode == :replace)
+    end
+
+    def at(path = [])
+      path = [path] unless path.is_a? Array
+      return self if path.empty?
+
+      field = find_field(path[0])
+
+      unless field.respond_to?(:output_definition)
+        raise ArgumentError, "Field #{path[0]} doesn't have nested output definition"
+      end
+
+      field.output_definition.at(path[1..-1])
+    end
+
+    def clear
+      @fields = []
     end
 
     def empty?
       @fields.empty?
     end
 
-  end
+    private
 
+    def field_index(field_id)
+      index = @fields.find_index do |f|
+        f.id == field_id
+      end
+      raise ArgumentError, "Field #{field_id} not found" if index.nil?
+      index
+    end
+
+    def insert_fields(index, fields, with_remove: false)
+      @fields.delete_at(index) if with_remove
+      fields.each_with_index do |f, i|
+        @fields.insert(index + i, f)
+      end
+    end
+  end
 end

lib/hammer_cli/output/fields.rb

@@ -3,9 +3,8 @@
 module Fields
 
   class Field
-
-    attr_reader :label
     attr_reader :path
+    attr_accessor :label
 
     def initialize(options={})
       @hide_blank = options[:hide_blank].nil? ? false : options[:hide_blank]
@@ -15,6 +14,10 @@ def initialize(options={})
       @options = options
     end
 
+    def id
+      @options[:id] || @options[:key] || @label
+    end
+
     def hide_blank?
       @hide_blank
     end