added table

lib/gitter/table.rb

@@ -0,0 +1,133 @@
+require 'action_view'
+
+module Gitter
+
+  class TableCell 
+
+    attr_reader :x, :y, :content
+
+    def initialize x, y, content
+      @x, @y, @content = x, y, content
+    end
+
+    def html opts = {}
+      Table.tag :td, content, opts.merge(class: "#{x} #{y}")
+    end
+
+    def header?
+      false
+    end
+  end
+
+  class TableHeaderCell < TableCell
+    attr_reader :content
+
+    def initialize content
+      @content = content
+    end
+
+    def html opts = {}
+      Table.tag :th, content, opts
+    end
+
+    def header?
+      true
+    end
+  end
+
+  class Table
+    extend ActionView::Helpers::TagHelper
+    extend ActionView::Helpers::OutputSafetyHelper
+
+    def self.tag tag, content, opts = {}
+      opts = opts.merge(class: "#{opts[:class]} grid pivot")
+      content_tag tag, raw(content), opts
+    end
+
+    attr_reader :title, :x_axis, :y_axis, :data, :opts
+
+    # axis: responds to each, yielding [key,title] or key 
+    #   # data: hash from [x_key,y_key] to cell_array 
+    def initialize title, x_axis, y_axis, data, opts = {}
+      @title, @x_axis, @y_axis, @data, @opts = title, x_axis, y_axis, data, opts
+      if label = opts[:show_sums]
+        add_sums_to_cells data
+        @x_axis = add_sums_to_axis @x_axis, label
+        @y_axis = add_sums_to_axis @y_axis, label
+      end
+    end
+
+    def rows
+      @rows ||= begin
+        rows = []
+        rows << x_header if x_header
+
+        rows + (y_axis||[nil]).map do |y,y_title|
+           row = (x_axis||[nil]).map do |x,x_title|
+             cell = data[pivot_key(x,y)]
+             cell = yield cell, x, y if block_given?
+             TableCell.new x, y, cell
+	   end
+           row.unshift TableHeaderCell.new(y_title||y) if y_axis
+	   row
+        end
+      end 
+    end
+
+    def html
+      @html ||= begin
+        h = rows.map do |row|
+          Table.tag :tr, (row.map{|cell| cell.html} * "\n")
+        end * "\n"
+	Table.tag :table, h
+      end
+    end
+
+    private
+
+    def x_header
+      @x_header ||= begin 
+        if x_axis
+          h = x_axis.map{|key,title| TableHeaderCell.new(title||key) }
+          h.unshift TableHeaderCell.new('') if y_axis
+          h
+        else
+          nil 
+        end
+      end
+    end
+
+    def pivot_key x, y
+      if x.nil? || y.nil?
+        x.nil? ? y : x
+      else
+        [x,y]
+      end
+    end
+
+    def add_sums_to_cells cells
+      xcells, ycells = {}, {}
+      sum = 0
+      cells.each do |key,value|
+        x, y = *key
+        xcells[y] = (xcells[y]||0) + value
+        ycells[x] = (ycells[x]||0) + value
+        sum += value
+      end
+      xcells.each{|y,sum| cells[pivot_key(:sum,y)] = sum}
+      ycells.each{|x,sum| cells[pivot_key(x,:sum)] = sum}
+      cells[[:sum,:sum]] = sum
+      cells
+    end
+
+    def add_sums_to_axis axis, label = nil
+      label = 'Sum' unless String === label
+      case axis
+      when Array then axis + [[:sum, label]]
+      when Hash  then axis.merge(:sum => label)
+      else nil;
+      end
+    end
+
+  end
+end