Added option for skipping null attribute values. Closes #26

src/XMLBuilder.coffee

@@ -23,12 +23,14 @@ module.exports = class XMLBuilder
   #
   # `options.headless` whether XML declaration and doctype will be included: true or false
   # `options.allowSurrogateChars` whether surrogates will be allowed: true or false
+  # `options.skipNullAttributes` whether attributes with null values will be ignored: true or false
   # `options.stringify` a set of functions to use for converting values to strings
   constructor: (name, options) ->
     if not name?
       throw new Error "Root element needs a name"
 
     options ?= {}
+    @options = options
     @stringify = new XMLStringifier options
 
     temp = new XMLElement @, 'doc' # temporary node so that we can call element()
@@ -42,7 +44,7 @@ module.exports = class XMLBuilder
       root.declaration options
 
       if options.pubID? or options.sysID?
-        root.doctype options.pubID, options.sysID
+        root.doctype options
 
 
   # Gets the root node

src/XMLElement.coffee

@@ -15,7 +15,7 @@ module.exports = class XMLElement extends XMLNode
   # `attributes` an object containing name/value pairs of attributes
   constructor: (parent, name, attributes) ->
     super parent
-    
+
     if not name?
       throw new Error "Missing element name"
 
@@ -25,8 +25,7 @@ module.exports = class XMLElement extends XMLNode
 
     @attributes = {}
     for own attName, attValue of attributes
-      if attName? and attValue?
-        @attributes[attName] = new XMLAttribute @, attName, attValue
+      @attribute attName, attValue
 
 
   # Clones self
@@ -53,7 +52,7 @@ module.exports = class XMLElement extends XMLNode
         clonedChild = child.clone(deep)
         clonedChild.parent = clonedSelf
         clonedSelf.children.push clonedChild
-        
+
     return clonedSelf
 
 
@@ -63,7 +62,8 @@ module.exports = class XMLElement extends XMLNode
   # `value` attribute value
   attribute: (name, value) ->
     value = value.apply() if _.isFunction value
-    @attributes[name] = new XMLAttribute @, name, value
+    if not @options.skipNullAttributes or value?
+      @attributes[name] = new XMLAttribute @, name, value
     return @
 
 

src/XMLNode.coffee

@@ -8,6 +8,7 @@ module.exports = class XMLNode
   #
   # `parent` the parent node
   constructor: (@parent) ->
+    @options = @parent.options
     @stringify = @parent.stringify
 
 

src/index.coffee

@@ -15,6 +15,7 @@ XMLBuilder = require './XMLBuilder'
 #
 # `options.headless` whether XML declaration and doctype will be included: true or false
 # `options.allowSurrogateChars` whether surrogates will be allowed: true or false
+# `options.skipNullAttributes` whether attributes with null values will be ignored: true or false
 # `options.stringify` a set of functions to use for converting values to strings
 module.exports.create = (name, xmldec, doctype, options) ->
   options = _.extend { }, xmldec, doctype, options

test/attributes.coffee

@@ -0,0 +1,82 @@
+vows = require 'vows'
+assert = require 'assert'
+
+xmlbuilder = require '../src/index.coffee'
+
+vows
+    .describe('Editing')
+    .addBatch
+        'Add attribute':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true })
+                    .ele('node', 'element', {"first":"1", "second":"2"})
+                        .att("third", "3")
+
+            'resulting XML': (doc) ->
+                xml = '<test4><node first="1" second="2" third="3">element</node></test4>'
+                assert.strictEqual doc.end(), xml
+
+        'Remove attribute':
+            topic: () ->
+                root = xmlbuilder.create('test4', { headless: true })
+                ele = root.ele('node', 'element', {"first":"1", "second":"2", "third":"3"})
+                ele.removeAttribute("second")
+                root
+
+            'resulting XML': (doc) ->
+                xml = '<test4><node first="1" third="3">element</node></test4>'
+                assert.strictEqual doc.end(), xml
+
+        'Throw if null attribute (ele)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true })
+
+            'resulting XML': (root) ->
+                assert.throws ->
+                    root.ele('node', 'element', {"first":null, "second":"2"})
+
+        'Throw if null attribute (att)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true })
+
+            'resulting XML': (root) ->
+                assert.throws ->
+                    root.ele('node').att("first")
+
+        'Throw if null attribute (JSON)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true })
+
+            'resulting XML': (root) ->
+                assert.throws ->
+                    root.ele({'@first': null})
+
+        'Skip if null attribute (ele)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true, skipNullAttributes: true })
+                    .ele('node', 'element', {"first":null, 'second': '2'})
+
+            'resulting XML': (doc) ->
+                xml = '<test4><node second="2">element</node></test4>'
+                assert.strictEqual doc.end(), xml
+
+        'Skip if null attribute (att)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true, skipNullAttributes: true })
+                    .ele('node').att("first")
+
+            'resulting XML': (doc) ->
+                xml = '<test4><node/></test4>'
+                assert.strictEqual doc.end(), xml
+
+        'Skip if null attribute (JSON)':
+            topic: () ->
+                xmlbuilder.create('test4', { headless: true, skipNullAttributes: true })
+                    .ele({'@first': null, '@second': '2'})
+
+            'resulting XML': (doc) ->
+                xml = '<test4 second="2"/>'
+                assert.strictEqual doc.end(), xml
+
+    .export(module)
+