Fixes #19135 - Possibility to limit fields that are displayed

lib/hammer_cli/main.rb

@@ -39,6 +39,9 @@ class MainCommand < AbstractCommand
     option ["--interactive"], "INTERACTIVE", _("Explicitly turn interactive mode on/off"),
       :format => HammerCLI::Options::Normalizers::Bool.new,
       :context_target => :interactive
+    option ["--only"], "FIELDS", _("Show selected columns or fields only"),
+      :format => HammerCLI::Options::Normalizers::List.new,
+      :context_target => :only
     option ["--no-headers"], :flag, _("Hide headers from output")
     option ["--csv"], :flag, _("Output as CSV (same as --output=csv)")
     option ["--output"], "ADAPTER", _("Set output format. One of [%s]") %

lib/hammer_cli/output/adapter/tree_structure.rb

@@ -7,9 +7,10 @@ def initialize(context={}, formatters={})
     end
 
     def prepare_collection(fields, collection)
-      collection.map do |element|
+      prepared = collection.map do |element|
         render_fields(fields, element)
       end
+      reduce_collection(prepared)
     end
 
     protected
@@ -75,5 +76,27 @@ def numbered_data(data)
       end
     end
 
+    private
+
+    def reduce_collection(collection)
+      return collection unless @context.key?(:only)
+      reduced = []
+      collection.each do |record|
+        reduced << reduce_record(record, @context[:only])
+      end
+      reduced
+    end
+
+    def reduce_record(record, keys)
+      reduced = {}
+      record.each do |key, value|
+        if keys.include?(key)
+          reduced[key] = value
+        elsif value.is_a? Hash
+          reduced.merge!(reduce_record(value, keys))
+        end
+      end
+      reduced
+    end
   end
 end

lib/hammer_cli/output/output.rb

@@ -17,13 +17,15 @@ def print_error(msg, details=nil, msg_params={})
     end
 
     def print_record(definition, record)
+      adjust_definition(definition)
       adapter.print_record(definition.fields, record)
     end
 
     def print_collection(definition, collection)
       unless collection.class <= HammerCLI::Output::RecordCollection
         collection = HammerCLI::Output::RecordCollection.new([collection].flatten(1))
       end
+      adjust_definition(definition)
       adapter.print_collection(definition.fields, collection)
     end
 
@@ -69,5 +71,11 @@ def init_adapter(adapter_name)
       @adapter ||= self.class.adapters[adapter_name].new(context, self.class.formatters)
     end
 
+    def adjust_definition(definition)
+      return unless @context.key?(:only)
+      return if adapter.class <= HammerCLI::Output::Adapter::TreeStructure
+      labels = @context[:only].map(&:downcase)
+      definition.select_fields!(deep_select: true, labels: labels)
+    end
   end
 end

test/unit/output/adapter/base_test.rb

@@ -220,6 +220,23 @@
 
     end
 
+    context '--only' do
+      let(:selected_fields) { [name.label] }
+      let(:context) { { :only => selected_fields, :adapter => :base } }
+      let(:output) { HammerCLI::Output::Output.new(context) }
+
+      it 'should print selected fields only' do
+        fields = [name, surname, city]
+        output_definition = HammerCLI::Output::Definition.new
+        output_definition.fields = fields
+        expected_output = [
+          'Name: John',
+          "\n"
+        ].join("\n")
+
+        proc { output.print_collection(output_definition, data) }.must_output(expected_output)
+      end
+    end
   end
 
 end

test/unit/output/adapter/csv_test.rb

@@ -227,6 +227,20 @@ def format(data, field_params={})
 
     end
 
+    context '--only' do
+      let(:selected_fields) { [field_name.label] }
+      let(:context) { {:only => selected_fields, :adapter => :csv } }
+      let(:output) { HammerCLI::Output::Output.new(context) }
+
+      it 'should print selected fields only' do
+        fields = [field_name, field_started_at]
+        output_definition = HammerCLI::Output::Definition.new
+        output_definition.fields = fields
+        expected_output = "Name\nJohn Doe\n"
+
+        proc { output.print_collection(output_definition, data) }.must_output(expected_output)
+      end
+    end
   end
 
   context "print message" do

test/unit/output/adapter/json_test.rb

@@ -268,6 +268,18 @@
 
     end
 
+    context '--only' do
+      let(:selected_fields) { [name.label] }
+      let(:context) { {:only => selected_fields } }
+
+      it 'should print selected fields only' do
+        fields = [name, surname, city]
+        hash = [{ 'Name' => 'John' }]
+        expected_output = JSON.pretty_generate(hash) + "\n"
+
+        proc { adapter.print_collection(fields, data) }.must_output(expected_output)
+      end
+    end
   end
 
 end

test/unit/output/adapter/table_test.rb

@@ -380,6 +380,27 @@ def format(data, field_params={})
 
     end
 
+    context '--only' do
+      let(:selected_fields) { [field_firstname.label] }
+      let(:context) { {:only => selected_fields, :adapter => :table } }
+      let(:output) { HammerCLI::Output::Output.new(context) }
+
+      it 'should print selected fields only' do
+        fields = [field_firstname, field_lastname, field_long]
+        output_definition = HammerCLI::Output::Definition.new
+        output_definition.fields = fields
+        expected_output = [
+          "---------",
+          "FIRSTNAME",
+          "---------",
+          "John     ",
+          "---------",
+          ""
+        ].join("\n")
+
+        proc { output.print_collection(output_definition, data) }.must_output(expected_output)
+      end
+    end
   end
 
 end

test/unit/output/adapter/yaml_test.rb

@@ -265,6 +265,18 @@
 
     end
 
+    context '--only' do
+      let(:selected_fields) { [name.label] }
+      let(:context) { { :only => selected_fields } }
+
+      it 'should print selected fields only' do
+        fields = [name, surname, city]
+        hash = [{ 'Name' => 'John' }]
+        expected_output = YAML.dump(hash)
+
+        proc { adapter.print_collection(fields, data) }.must_output(expected_output)
+      end
+    end
   end
 
 end