lib/datashift/column_packer.rb in datashift-0.15.0 vs lib/datashift/column_packer.rb in datashift-0.16.0

@@ -3,62 +3,126 @@
 # Date ::     Dec 2012
 # License::   MIT
 #
 # Details::   Helper for creating consistent import/export format
 #             of model's attributes/associations
-# 
 #
-require 'exporter_base'
-require 'csv'
-
 module DataShift
 
   module ColumnPacker
 
-    
-    def text_delim
-      @text_delim ||= "\'"
-    end
+    include Delimiters
 
-    def text_delim=(x)
-      @text_delim = x
-    end
-    
     # Return opposite of text delim - "hello, 'barry'" => '"hello, "barry""'
     def escape_text_delim
       return '"' if text_delim == "\'"
       "\'"
     end
-    
- 
+
+
+    # Ensure a value is written to CSV correctly
+    # TODO - better ways ?? - see transcoding and String#encode
+
+    def escape_for_csv(value)
+      text = value.to_s.gsub(text_delim, escape_text_delim()).gsub("\n", "\\n")
+
+      text = "#{text_delim}#{text}#{text_delim}" if(text.include?(Delimiters::csv_delim))
+      text
+    end
+
+
+    def to_headers( records, associations = nil, options = {} )
+      return if( !records.first.is_a?(ActiveRecord::Base) || records.empty?)
+
+      only = *options[:only] ? [*options[:only]] : nil
+
+      headers =[]
+
+      if associations
+        details_mgr = DataShift::MethodDictionary.method_details_mgrs[records.first.class]
+
+        [*associations].each do |a|
+
+          details_mgr.get_list(a).each do  |md|
+
+            next if(only && !only.include?( md.name.to_sym ) )
+
+            headers << "#{md.operator}"
+
+          end
+        end if(details_mgr)
+
+      else
+
+        headers = records.first.class.columns.collect( &:name )
+      end
+
+      headers
+    end
+
+
     # Convert an AR instance to a single column
-  
-    def record_to_column(record, attribute_delim = Delimiters::csv_delim) 
-    
-      csv_data = []
-      record.serializable_hash.each do |name, value|
-        value = 'nil' if value.nil?
-        text = value.to_s.gsub(@text_delim, escape_text_delim())
-        csv_data << "#{name.to_sym} => #{text}"
+    #    e.g User  :  ":name = > 'tom', :role => 'developer'"
+    #
+    # OPTIONS
+    #     with_only  Specify (as symbols) columns for association types to export
+    #     json:         Export association data in single column in JSON format
+    #
+    def record_to_column(record, options = {})
+
+      return "" if(record.nil? || (record.respond_to?(:each) && record.empty?) )
+
+      with_only = *options[:with_only] ? [*options[:with_only]] : nil
+
+      return record.to_json if(options[:json] && !with_only) # packs associations into single column
+
+      if( record.respond_to?(:each) )
+
+        return "" if(record.empty?)
+
+        data = []
+
+        record.each { |r| data << record_to_column(r, options); }
+
+        if(options[:json])
+          return data.to_json
+        else
+          return "#{data.join(Delimiters::multi_assoc_delim)}"
+        end
+
+      else
+
+        data = options[:json] ? {} : []
+
+        record.serializable_hash.each do |name, value|
+          next if(with_only && !with_only.include?( name.to_sym ) )
+
+          if(options[:json])
+            data[name] = value
+          else
+            data << "#{name.to_sym} #{Delimiters::key_value_sep} #{value.to_s.gsub(text_delim, escape_text_delim)}"
+          end
+        end
+
+        if(options[:json])#
+          return data.to_json
+        else
+          "#{Delimiters::attribute_list_start}#{data.join(Delimiters::multi_value_delim)}#{Delimiters::attribute_list_end}"
+        end
+
       end
-      "#{csv_data.join(attribute_delim)}"
+
     end
-    
-    
+
+
     # Convert an AR instance to a set of CSV columns
     def record_to_csv(record, options = {})
       csv_data = record.serializable_hash.values.collect { |value| escape_for_csv(value) }
 
       [*options[:methods]].each { |x| csv_data << escape_for_csv(record.send(x)) if(record.respond_to?(x)) } if(options[:methods])
-      
+
       csv_data.join( Delimiters::csv_delim )
     end
-    
-    def escape_for_csv(value)
-      text = value.to_s.gsub(@text_delim, escape_text_delim())
-      
-      text = "#{@text_delim}#{text}#{@text_delim}" if(text.include?(Delimiters::csv_delim)) 
-      text
-    end
-    
+
+
   end
 end