Fill in table

src/table-layout.js

@@ -4,11 +4,11 @@ var Cell = require('./cell');
 
 function makeTableLayout(rows){
   var cellRows = generateCells(rows);
-  fillInLayout(cellRows);
+  expandCells(cellRows);
   return cellRows;
 }
 
-function fillInLayout(cellRows){
+function expandCells(cellRows){
   for(var rowIndex = cellRows.length-1; rowIndex >= 0; rowIndex--){
     var cellColumns = cellRows[rowIndex];
     for(var columnIndex = 0; columnIndex < cellColumns.length; columnIndex++){
@@ -28,6 +28,46 @@ function fillInLayout(cellRows){
   }
 }
 
+function fillInTable(rows){
+  var height = rows.length;
+  var width = maxWidth(rows);
+  for(var rowIndex = 0; rowIndex < height; rowIndex++){
+    var row = rows[rowIndex];
+    for(var colIndex = 0; colIndex < width; colIndex++){
+      var cell = row[colIndex];
+      if(!cell){
+        var i = colIndex+1;
+        while(i < width && !row[i]){
+          row[i] = new Cell.NoOpCell();
+          i++;
+        }
+        var j = rowIndex + 1;
+        while(j < height && allBlank(rows[j],colIndex,i)){
+          for(var k = colIndex+1; k < i; k++){
+            rows[j][k] = new Cell.NoOpCell();
+          }
+          j++;
+        }
+        var rowSpan = j - rowIndex;
+        var blankCell = new Cell(
+          {colSpan:i-colIndex,rowSpan: rowSpan}
+        );
+        row[colIndex] = blankCell;
+        for(var n = 1; n < rowSpan; n++){
+          rows[rowIndex+n][colIndex] = new Cell.RowSpanCell(blankCell);
+        }
+      }
+    }
+  }
+}
+
+function allBlank(row,from,to){
+  for(var i = from; i < to; i++){
+    if(row[i]) return false;
+  }
+  return true;
+}
+
 function generateCells(rows){
   return _.map(rows,function(row){
     return _.map(row,function(cell){
@@ -44,5 +84,6 @@ function maxWidth(rows){
 
 module.exports = {
   makeTableLayout:makeTableLayout,
-  maxWidth:maxWidth
+  maxWidth:maxWidth,
+  fillInTable:fillInTable
 };

test/table-layout-test.js

@@ -3,6 +3,7 @@ describe('tableLayout', function () {
   var tableLayout = require('../src/table-layout');
   var makeTableLayout = tableLayout.makeTableLayout;
   var maxWidth = tableLayout.maxWidth;
+  var fillInTable = tableLayout.fillInTable;
   var chai = require('chai');
   var expect = chai.expect;
   var _ = require('lodash');
@@ -100,6 +101,67 @@ describe('tableLayout', function () {
     expect(maxWidth([[1],[1,2],[1,2,3,4,5]])).to.equal(5);
   });
 
+  describe('fillInTable',function(){
+    function mc(opts){
+      return new Cell(opts);
+    }
+
+    it('will blank out individual cells',function(){
+      var cells = [
+        [null, mc('a')],
+        [mc('b'), null]
+      ];
+      fillInTable(cells);
+
+      checkLayout(cells,[
+        ['', 'a'],
+        ['b', '']
+      ]);
+    });
+
+    it('will autospan to the right',function(){
+      var cells = [
+        [null, null],
+        [null, mc('a')]
+      ];
+      fillInTable(cells);
+
+      checkLayout(cells,[
+        [{content:'',colSpan:2}, null],
+        ['', 'a']
+      ]);
+    });
+
+    it('will autospan down',function(){
+      var cells = [
+        [null, mc('a')],
+        [null, null]
+      ];
+      fillInTable(cells);
+
+      checkLayout(cells,[
+        [{content:'',rowSpan:2}, 'a'],
+        [{spannerFor:[0,0]}, '']
+      ]);
+    });
+
+    it('will autospan right and down',function(){
+      var cells = [
+        [null,  null,    mc('a')],
+        [null,  null,    null],
+        [null,  mc('b'), null]
+      ];
+      fillInTable(cells);
+
+      checkLayout(cells,[
+        [{content:'',colSpan:2, rowSpan:2}, null, 'a'],
+        [{spannerFor:[0,0]}, null, {content:'', colSpan:1, rowSpan:2}],
+        ['','b',{spannerFor:[1,2]}]
+      ]);
+    });
+
+  });
+
   /**
    * Provides a shorthand for validating a table of cells.
    * To pass, both arrays must have the same dimensions, and each cell in `actualRows` must