diff --git a/dist/react-json-editor.js b/dist/react-json-editor.js
index 545221b..9a42204 100644
--- a/dist/react-json-editor.js
+++ b/dist/react-json-editor.js
@@ -257,6 +257,10 @@ return /******/ (function(modules) { // webpackBootstrap
 	  return typeof x == 'number' && x >= 0 && x % 1 == 0;
 	};
 
+	var isNil = function(x) {
+	  return (typeof x === 'undefined' || x === null);
+	};
+
 	var object = function() {
 	  var args = Array.prototype.slice.call(arguments);
 	  var result = [];
@@ -391,7 +395,8 @@ return /******/ (function(modules) { // webpackBootstrap
 	  prune  : prune,
 	  split  : split,
 	  map    : map,
-	  mapKeys: mapKeys
+	  mapKeys: mapKeys,
+	  isNil  : isNil
 	};
 
 
@@ -848,6 +853,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	'use strict';
 
 	var React = __webpack_require__(2);
+	var ou = __webpack_require__(3);
 	var $ = React.DOM;
 
 	var normalizer = __webpack_require__(12);
@@ -873,10 +879,11 @@ return /******/ (function(modules) { // webpackBootstrap
 	    }
 	  },
 	  render: function() {
+	    var value = ou.isNil(this.props.value)? '' : this.props.value;
 	    return $.input({
 	      type      : "text",
 	      name      : this.props.label,
-	      value     : this.props.value || '',
+	      value     : value,
 	      onKeyPress: this.handleKeyPress,
 	      onChange  : this.handleChange });
 	  }
@@ -922,18 +929,18 @@ return /******/ (function(modules) { // webpackBootstrap
 	'use strict';
 
 	var normalizer = __webpack_require__(12);
-
+	var ou = __webpack_require__(3);
 
 	exports.string = function(text) {
 	  return normalizer.string(text);
 	};
 
 	exports.integer = function(text) {
-	  return text ? parseInt(normalizer.integer(text)) : null;
+	  return ou.isNil(text) ? null : parseInt(normalizer.integer(text));
 	};
 
 	exports.number = function(text) {
-	  return text ? parseFloat(normalizer.number(text)) : null;
+	  return ou.isNil(text) ? null : parseFloat(normalizer.number(text));
 	};
 
 
@@ -1190,7 +1197,6 @@ return /******/ (function(modules) { // webpackBootstrap
 	'use strict';
 
 	var ou = __webpack_require__(3);
-	var alternative = __webpack_require__(8);
 
 	var checkNumber = function(schema, instance) {
 	  var errors = [];
@@ -1343,9 +1349,6 @@ return /******/ (function(modules) { // webpackBootstrap
 	  if (instance == null)
 	    instance = {};
 
-	  var alternativeSchema = alternative.schema(instance, schema, context);
-	  schema = alternativeSchema || schema;
-
 	  if (instance.constructor !== Object)
 	    result.push({ path: [], errors: ['must be a plain object'] });
 	  else {
diff --git a/dist/react-json-editor.min.js b/dist/react-json-editor.min.js
index 7ca8a25..fa8bde6 100644
--- a/dist/react-json-editor.min.js
+++ b/dist/react-json-editor.min.js
@@ -1 +1 @@
-!function(e,t){"object"==typeof exports&&"object"==typeof module?module.exports=t(require("react")):"function"==typeof define&&define.amd?define(["react"],t):"object"==typeof exports?exports["react-json-editor"]=t(require("react")):e["react-json-editor"]=t(e.react)}(this,function(e){return function(e){function t(n){if(r[n])return r[n].exports;var s=r[n]={exports:{},id:n,loaded:!1};return e[n].call(s.exports,s,s.exports,t),s.loaded=!0,s.exports}var r={};return t.m=e,t.c=r,t.p="",t(0)}([function(e,t,r){"use strict";e.exports=r(1)},function(e,t,r){"use strict";function n(e){var t,r,n={};for(t=0;t<e.length;++t)r=e[t],n[s(r.path)]=r.errors;return n}function s(e){return e.join("_")}function i(e){return e.context||e.schema}var a=r(2),o=a.DOM,u=r(3),p=r(4),l=r(17),c=r(18);e.exports=a.createClass({displayName:"Form",getInitialState:function(){var e=this.props.values,t=this.validate(this.props.schema,e,i(this.props));return{values:e,output:e,errors:t}},componentWillReceiveProps:function(e){var t=e.values||this.state.values,r=e.values||this.state.output;this.setState({values:t,output:r,errors:this.validate(e.schema,r,i(e))})},setValue:function(e,t,r){var n=this.props.schema,s=i(this.props),a=l(u.setIn(this.state.values,e,t),n,s),o=l(u.setIn(this.state.output,e,r),n,s),p=this.validate(n,o,s);this.props.submitOnChange?this.props.onSubmit(o,null,p):this.setState({values:a,output:o,errors:p})},getValue:function(e){return u.getIn(this.state.values,e)},getErrors:function(e){return this.state.errors[s(e)]},validate:function(e,t,r){var s=this.props.validate||c;return n(s(e,t,r))},preventSubmit:function(e){e.preventDefault()},handleSubmit:function(e){this.props.onSubmit(this.state.output,e.target.value,this.state.errors)},handleKeyPress:function(e){13===e.keyCode&&this.props.enterKeySubmits&&this.props.onSubmit(this.state.output,this.props.enterKeySubmits)},renderButtons:function(){var e=this.handleSubmit;if("function"==typeof this.props.buttons)return this.props.buttons(e);var t=(this.props.buttons||["Cancel","Submit"]).map(function(t){return o.input({type:"submit",key:t,value:t,onClick:e})});return o.p(null,t)},render:function(){var e=p.make(p,{schema:this.props.schema,context:i(this.props),fieldWrapper:this.props.fieldWrapper,sectionWrapper:this.props.sectionWrapper,handlers:this.props.handlers,hints:this.props.hints,path:[],update:this.setValue,getValue:this.getValue,getErrors:this.getErrors});return o.form({onSubmit:this.preventSubmit,onKeyPress:this.handleKeyPress,className:this.props.className},this.props.extraButtons?this.renderButtons():o.span(),e,this.renderButtons())}})},function(t,r){t.exports=e},function(e,t){"use strict";var r=function(e){return"number"==typeof e&&e>=0&&e%1==0},n=function(){var e,t=Array.prototype.slice.call(arguments),n=[];for(e=0;e+1<t.length;e+=2)r(t[e])||(n={});for(e=0;e+1<t.length;e+=2)n[t[e]]=t[e+1];return n},s=function(){var e,t,r,n=Array.prototype.slice.call(arguments),s=n.every(Array.isArray)?[]:{};for(e in n){t=n[e];for(r in t)s[r]=t[r]}return s},i=function(e,t){return 0==t.length||void 0==e?e:i(e[t[0]],t.slice(1))},a=function(e,t,r){if(0==t.length)return r;var i=null==e?null:e[t[0]],r=a(i||[],t.slice(1),r);return s(e,n(t[0],r))},o=function(e){var t=[].slice.call(arguments),r=Array.isArray(e)?[]:{};for(var n in e)t.indexOf(n)<0&&(r[n]=e[n]);return r},u=function(e){var t,r,n,s;if(null==e||""===e)t=null;else if(e.constructor===Array||e.constructor===Object){r=Array.isArray(e),t=r?[]:{};for(n in e)s=u(e[n]),null!=s&&(r?t.push(s):t[n]=s);0==Object.keys(t).length&&(t=null)}else t=e;return t},p=function(e,t){var r={},n={};for(key in t){var s=t[key];e(key,s)?r[key]=s:n[key]=s}return[r,n]},l=function(e,t){var r,n={};for(r in t)n[r]=e(t[r]);return n},c=function(e,t){var r,n={};for(r in t)n[e(r)]=t[r];return n};e.exports={object:n,merge:s,without:o,getIn:i,setIn:a,prune:u,split:p,map:l,mapKeys:c}},function(e,t,r){"use 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e=this.props.fields||{},t=this.props.value||{},r=[s.input({key:"input",type:"file",onChange:this.loadFile}),s.dl({key:"fileProperties"},s.dt(null,"Name"),s.dd(null,t.name||"-"),s.dt(null,"Size"),s.dd(null,t.size||"-"),s.dt(null,"Type"),s.dd(null,t.type||"-"))];return o.section(this.props,r.concat(a.object(e,this.props)))}});e.exports=u},function(e,t,r){"use strict";function n(e,t){var r,n,s=Object.keys(t||{}),i=[];for(r in e||[])n=e[r],s.indexOf(n)>=0&&i.push(n);for(r in s)n=s[r],i.indexOf(n)<0&&i.push(n);return i}var s=r(3),i=r(8),a={alternative:function(e,t){var r=i.schema(t.getValue(t.path),t.schema,t.context);return a.object(e,s.merge(t,{schema:r}))},array:function(e,t){for(var r=function(e,t,r){return function(s){if(n(t,r)||a(t,r)){var i=e.getValue(e.path),o=i.splice(s,1);i.splice(t,0,o[0]),e.update(e.path,i,i)}}},n=function(e,t){return e>0&&t-1>e},i=function(e,t,r){return function(){if(n(t,r)){var 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n=r(2),s=r(12),i=r(13),a=n.createClass({displayName:"UserDefinedField",normalize:function(e){var t=s[this.props.type];return t?t(e):e},parse:function(e){var t=i[this.props.type];return t?t(e):e},handleChange:function(e){var t=this.normalize(e);this.props.update(this.props.path,t,this.parse(t))},handleKeyPress:function(e){13===e.keyCode&&e.preventDefault()},render:function(){return n.createElement(this.props.component,{schema:this.props.schema,value:this.props.value||"",onKeyPress:this.handleKeyPress,onChange:this.handleChange})}});e.exports=a},function(e,t,r){"use strict";var n=r(2),s=n.DOM,i=r(12),a=r(13),o=n.createClass({displayName:"Selection",normalize:function(e){var t=this.props.type||"string";return i[t](e)},parse:function(e){var t=this.props.type||"string";return a[t](e)},handleChange:function(e){var t=this.normalize(e.target.value);this.props.update(this.props.path,t,this.parse(t))},render:function(){var e=this.props.names;return 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e.properties)if(t.hasOwnProperty(n))for(i=c(e.properties[n],t[n],r),a=0;a<i.length;++a)o.push({path:[n].concat(i[a].path),errors:i[a].errors});else u(e,n)&&o.push({path:[n],errors:[u(e,n)]});return o};var p=function(e){return[].concat.apply([],e)},l=function(e,t){var r=e.$ref;if(r){if(!r.match(/^#(\/([a-zA-Z_][a-zA-Z_0-9]*|[0-9]+))*$/))throw new Error("reference "+r+" has unsupported format");return{allOf:[n.without(e,"$ref"),n.getIn(t,r.split("/").slice(1))]}}return e},c=function(e,t,r){var s=r||e,i=l(e,s);if(i.allOf){var a=[n.without(i,"allOf")].concat(i.allOf).map(function(e){return c(e,t,s)});return p(a)}var u=i["enum"]?"enum":i.type;return u?o[u](i,t,s):[]};e.exports=c}])});
\ No newline at end of file
+!function(e,t){"object"==typeof exports&&"object"==typeof module?module.exports=t(require("react")):"function"==typeof define&&define.amd?define(["react"],t):"object"==typeof exports?exports["react-json-editor"]=t(require("react")):e["react-json-editor"]=t(e.react)}(this,function(e){return function(e){function t(n){if(r[n])return r[n].exports;var s=r[n]={exports:{},id:n,loaded:!1};return e[n].call(s.exports,s,s.exports,t),s.loaded=!0,s.exports}var r={};return t.m=e,t.c=r,t.p="",t(0)}([function(e,t,r){"use strict";e.exports=r(1)},function(e,t,r){"use strict";function n(e){var t,r,n={};for(t=0;t<e.length;++t)r=e[t],n[s(r.path)]=r.errors;return n}function s(e){return e.join("_")}function i(e){return e.context||e.schema}var a=r(2),o=a.DOM,u=r(3),p=r(4),l=r(17),c=r(18);e.exports=a.createClass({displayName:"Form",getInitialState:function(){var e=this.props.values,t=this.validate(this.props.schema,e,i(this.props));return{values:e,output:e,errors:t}},componentWillReceiveProps:function(e){var t=e.values||this.state.values,r=e.values||this.state.output;this.setState({values:t,output:r,errors:this.validate(e.schema,r,i(e))})},setValue:function(e,t,r){var n=this.props.schema,s=i(this.props),a=l(u.setIn(this.state.values,e,t),n,s),o=l(u.setIn(this.state.output,e,r),n,s),p=this.validate(n,o,s);this.props.submitOnChange?this.props.onSubmit(o,null,p):this.setState({values:a,output:o,errors:p})},getValue:function(e){return u.getIn(this.state.values,e)},getErrors:function(e){return this.state.errors[s(e)]},validate:function(e,t,r){var s=this.props.validate||c;return n(s(e,t,r))},preventSubmit:function(e){e.preventDefault()},handleSubmit:function(e){this.props.onSubmit(this.state.output,e.target.value,this.state.errors)},handleKeyPress:function(e){13===e.keyCode&&this.props.enterKeySubmits&&this.props.onSubmit(this.state.output,this.props.enterKeySubmits)},renderButtons:function(){var e=this.handleSubmit;if("function"==typeof this.props.buttons)return this.props.buttons(e);var t=(this.props.buttons||["Cancel","Submit"]).map(function(t){return o.input({type:"submit",key:t,value:t,onClick:e})});return o.p(null,t)},render:function(){var e=p.make(p,{schema:this.props.schema,context:i(this.props),fieldWrapper:this.props.fieldWrapper,sectionWrapper:this.props.sectionWrapper,handlers:this.props.handlers,hints:this.props.hints,path:[],update:this.setValue,getValue:this.getValue,getErrors:this.getErrors});return o.form({onSubmit:this.preventSubmit,onKeyPress:this.handleKeyPress,className:this.props.className},this.props.extraButtons?this.renderButtons():o.span(),e,this.renderButtons())}})},function(t,r){t.exports=e},function(e,t){"use strict";var r=function(e){return"number"==typeof e&&e>=0&&e%1==0},n=function(e){return"undefined"==typeof e||null===e},s=function(){var e,t=Array.prototype.slice.call(arguments),n=[];for(e=0;e+1<t.length;e+=2)r(t[e])||(n={});for(e=0;e+1<t.length;e+=2)n[t[e]]=t[e+1];return n},i=function(){var e,t,r,n=Array.prototype.slice.call(arguments),s=n.every(Array.isArray)?[]:{};for(e in n){t=n[e];for(r in t)s[r]=t[r]}return s},a=function(e,t){return 0==t.length||void 0==e?e:a(e[t[0]],t.slice(1))},o=function(e,t,r){if(0==t.length)return r;var n=null==e?null:e[t[0]],r=o(n||[],t.slice(1),r);return i(e,s(t[0],r))},u=function(e){var t=[].slice.call(arguments),r=Array.isArray(e)?[]:{};for(var n in e)t.indexOf(n)<0&&(r[n]=e[n]);return r},p=function(e){var t,r,n,s;if(null==e||""===e)t=null;else if(e.constructor===Array||e.constructor===Object){r=Array.isArray(e),t=r?[]:{};for(n in e)s=p(e[n]),null!=s&&(r?t.push(s):t[n]=s);0==Object.keys(t).length&&(t=null)}else t=e;return t},l=function(e,t){var r={},n={};for(key in t){var s=t[key];e(key,s)?r[key]=s:n[key]=s}return[r,n]},c=function(e,t){var r,n={};for(r in t)n[r]=e(t[r]);return n},h=function(e,t){var r,n={};for(r in t)n[e(r)]=t[r];return n};e.exports={object:s,merge:i,without:u,getIn:a,setIn:o,prune:p,split:l,map:c,mapKeys:h,isNil:n}},function(e,t,r){"use strict";e.exports={CheckBox:r(5),FileField:r(6),InputField:r(11),UserDefinedField:r(14),Selection:r(15),make:r(16)}},function(e,t,r){"use strict";var n=r(2),s=n.DOM,i=n.createClass({displayName:"CheckBox",handleChange:function(e){var t=e.target.checked?!0:null;this.props.update(this.props.path,t,t)},render:function(){return s.input({name:this.props.label,type:"checkbox",checked:this.props.value||!1,onChange:this.handleChange})}});e.exports=i},function(e,t,r){"use strict";var n=r(2),s=n.DOM,i=r(3),a=r(7),o=r(10),u=n.createClass({displayName:"FileField",loadFile:function(e){var t=new FileReader,r=e.target.files[0],n=i.merge(this.props.getValue(this.props.path),{name:r.name,type:r.type,size:r.size});this.props.update(this.props.path,n,n),t.onload=function(e){n.data=e.target.result,this.props.update(this.props.path,n,n)}.bind(this),r&&("dataURL"===this.props.mode?t.readAsDataURL(r):t.readAsText(r))},render:function(){var e=this.props.fields||{},t=this.props.value||{},r=[s.input({key:"input",type:"file",onChange:this.loadFile}),s.dl({key:"fileProperties"},s.dt(null,"Name"),s.dd(null,t.name||"-"),s.dt(null,"Size"),s.dd(null,t.size||"-"),s.dt(null,"Type"),s.dd(null,t.type||"-"))];return o.section(this.props,r.concat(a.object(e,this.props)))}});e.exports=u},function(e,t,r){"use strict";function n(e,t){var r,n,s=Object.keys(t||{}),i=[];for(r in e||[])n=e[r],s.indexOf(n)>=0&&i.push(n);for(r in s)n=s[r],i.indexOf(n)<0&&i.push(n);return i}var s=r(3),i=r(8),a={alternative:function(e,t){var r=i.schema(t.getValue(t.path),t.schema,t.context);return a.object(e,s.merge(t,{schema:r}))},array:function(e,t){for(var r=function(e,t,r){return function(s){if(n(t,r)||a(t,r)){var i=e.getValue(e.path),o=i.splice(s,1);i.splice(t,0,o[0]),e.update(e.path,i,i)}}},n=function(e,t){return e>0&&t-1>e},i=function(e,t,r){return function(){if(n(t,r)){var s=e.getValue(e.path),i=s.splice(t,1);s.splice(t-1,0,i[0]),e.update(e.path,s,s)}}},a=function(e,t){return t>1&&t-2>e},o=function(e,t,r){return function(){if(a(t,r)){var n=e.getValue(e.path),s=n.splice(t,1);n.splice(t+1,0,s[0]),e.update(e.path,n,n)}}},u=function(e,t){return t>e},p=function(e,t,r){return function(){if(u(t,r)){var n=e.getValue(e.path);n.splice(t,1),e.update(e.path,n,n)}}},l=(t.getValue(t.path)||[]).length+1,c=[],h=0;l>h;++h)c.push(e.make(e,s.merge(t,{schema:t.schema.items,path:t.path.concat(h),move:r(t,h,l),moveUp:i(t,h,l),moveDown:o(t,h,l),canMoveUp:n(h,l),canMoveDown:a(h,l),removeItem:p(t,h,l),canRemoveItem:u(h,l)})));return c},object:function(e,t){var r=n(t.schema["x-ordering"],t.schema.properties);return r.map(function(r){return e.make(e,s.merge(t,{schema:t.schema.properties[r],path:t.path.concat(r)}))})}};e.exports=a},function(e,t,r){"use strict";var n=r(3),s=r(9);t.schema=function(e,t,r){var i,a,o;if(i=n.getIn(t,["x-hints","form","selector"])){var u=t.oneOf.map(function(e){return s(e,r)});return a=u.map(function(e){return n.getIn(e,["properties",i,"enum",0])||""}),o=(e||{})[i]||a[0],n.merge(n.setIn(u[a.indexOf(o)],["properties",i],n.merge(n.getIn(t,["properties",i]),{"enum":a})),{type:"object"})}}},function(e,t,r){"use strict";function n(e){var t=[].slice.call(arguments),r=Array.isArray(e)?[]:{};for(var n in e)t.indexOf(n)<0&&(r[n]=e[n]);return r}var s=r(3);e.exports=function(e,t){var r=e.$ref;if(r){if(!r.match(/^#(\/([a-zA-Z_][a-zA-Z_0-9]*|[0-9]+))*$/))throw new Error("reference "+r+" has unsupported format");return s.merge(s.getIn(t,r.split("/").slice(1)),n(e,"$ref"))}return e}},function(e,t,r){"use strict";var n=r(2),s=n.DOM,i=r(3),a=function(e){return e&&0!==e.length?"error":""},o=function(e,t){var r=[];return e&&e.length>0&&r.push(e),t&&t.length>0&&r.push(t.join("\n")),r.join("\n\n")},u=n.createClass({displayName:"FieldWrapper",render:function(){var e=[].concat(a(this.props.errors)||[],"form-element",this.props.classes||[]);return s.div({className:e.join(" "),key:this.props.label,title:o(this.props.description,this.props.errors)},s.label({htmlFor:this.props.label},this.props.title),this.props.children)}}),p=n.createClass({displayName:"SectionWrapper",render:function(){var e=this.props.path.length,t=[].concat("form-section",e>0?"form-subsection":[],this.props.classes||[]),r=[].concat(a(this.props.errors)||[],"form-section-title");return s.fieldset({className:t.join(" "),key:this.props.label},s.legend({className:r.join(" "),title:o(this.props.description,this.props.errors)},this.props.title),this.props.children)}}),l=function(e,t){var r={key:e.key,label:e.label,path:e.path,errors:e.errors,classes:i.getIn(e.schema,["x-hints","form","classes"]),title:e.schema.title,type:e.schema.type,description:e.schema.description,schema:e.schema};if(t&&e.isArrayItem){if(e.isArrayItem){var n=e.getValue(e.path),s=e.title;if(n){var a=i.getIn(e.schema,["x-hints","itemHeader","property"]),o=a&&n[a]||n.title||n.name;s=s&&o?s+" - "+o:o||s}r=i.merge(r,{title:s||r.title,move:e.move,moveUp:e.moveUp,moveDown:e.moveDown,canMoveUp:e.canMoveUp,canMoveDown:e.canMoveDown,removeItem:e.removeItem,canRemoveItem:e.canRemoveItem})}r=i.merge(r,{isArrayItem:e.isArrayItem})}return r};t.section=function(e,t){return n.isValidElement(e.sectionWrapper)?n.cloneElement(e.sectionWrapper,l(e,!0),t):n.createElement(e.sectionWrapper||p,l(e,!0),t)},t.field=function(e,t){return n.isValidElement(e.fieldWrapper)?n.cloneElement(e.fieldWrapper,l(e),t):n.createElement(e.fieldWrapper||u,l(e),t)}},function(e,t,r){"use strict";var n=r(2),s=r(3),i=n.DOM,a=r(12),o=r(13),u=n.createClass({displayName:"InputField",normalize:function(e){return a[this.props.type](e)},parse:function(e){return o[this.props.type](e)},handleChange:function(e){var t=this.normalize(e.target.value);this.props.update(this.props.path,t,this.parse(t))},handleKeyPress:function(e){13===e.keyCode&&e.preventDefault()},render:function(){var e=s.isNil(this.props.value)?"":this.props.value;return i.input({type:"text",name:this.props.label,value:e,onKeyPress:this.handleKeyPress,onChange:this.handleChange})}});e.exports=u},function(e,t){"use strict";t.string=function(e){return e.replace(/\s+/g," ").replace(/^ /,"").replace(/\u00ad/g,"")},t.integer=function(e){return e.replace(/[^-\d]/g,"").replace(/(.)-/g,"$1")},t.number=function(e){return e.replace(/[^-\.e\d]/gi,"").replace(/(e[^e]*)e/gi,"$1").replace(/([e.][^.]*)\./gi,"$1").replace(/([^e])-/gi,"$1").replace(/(e-?\d\d\d)\d/gi,"$1")}},function(e,t,r){"use strict";var n=r(12),s=r(3);t.string=function(e){return n.string(e)},t.integer=function(e){return s.isNil(e)?null:parseInt(n.integer(e))},t.number=function(e){return s.isNil(e)?null:parseFloat(n.number(e))}},function(e,t,r){"use strict";var n=r(2),s=r(12),i=r(13),a=n.createClass({displayName:"UserDefinedField",normalize:function(e){var t=s[this.props.type];return t?t(e):e},parse:function(e){var t=i[this.props.type];return t?t(e):e},handleChange:function(e){var t=this.normalize(e);this.props.update(this.props.path,t,this.parse(t))},handleKeyPress:function(e){13===e.keyCode&&e.preventDefault()},render:function(){return n.createElement(this.props.component,{schema:this.props.schema,value:this.props.value||"",onKeyPress:this.handleKeyPress,onChange:this.handleChange})}});e.exports=a},function(e,t,r){"use strict";var n=r(2),s=n.DOM,i=r(12),a=r(13),o=n.createClass({displayName:"Selection",normalize:function(e){var t=this.props.type||"string";return i[t](e)},parse:function(e){var t=this.props.type||"string";return a[t](e)},handleChange:function(e){var t=this.normalize(e.target.value);this.props.update(this.props.path,t,this.parse(t))},render:function(){var e=this.props.names;return s.select({name:this.props.label,value:this.props.value||this.props.values[0],onChange:this.handleChange},this.props.values.map(function(t,r){return s.option({key:t,value:t},e[r]||t)}))}});e.exports=o},function(e,t,r){"use strict";function n(e){return e.join("_")}var s=r(2),i=r(3),a=r(9),o=r(7),u=r(10);e.exports=function(e,t){var r=a(t.schema,t.context),p=r["x-hints"]||{},l=i.getIn(p,["form","inputComponent"]),c=n(t.path);if(t=i.merge(t,{schema:r,key:c,label:c,value:t.getValue(t.path),errors:t.getErrors(t.path),type:r.type}),void 0!==t.moveUp&&(t.isArrayItem?(delete t.isArrayItem,delete t.canMoveUp,delete t.canMoveDown,delete t.move,delete t.moveUp,delete t.moveDown):t.isArrayItem=!0),l)return t=i.merge(t,{component:t.handlers[l]}),u.field(t,s.createElement(e.UserDefinedField,t));if(p.fileUpload)return console.warn("DEPRECATION WARNING: built-in file upload will be removed"),t=i.merge(t,{fields:e}),s.createElement(e.FileField,i.merge(t,{mode:p.fileUpload.mode}));if(r.oneOf)return u.section(t,o.alternative(e,t));if(r["enum"])return t=i.merge(t,{values:r["enum"],names:r.enumNames||r["enum"]}),u.field(t,s.createElement(e.Selection,t));switch(r.type){case"boolean":return u.field(t,s.createElement(e.CheckBox,t));case"object":return u.section(t,o.object(e,t));case"array":return u.section(t,o.array(e,t));case"number":case"integer":case"string":default:return u.field(t,s.createElement(e.InputField,t))}}},function(e,t,r){"use strict";function n(e,t,r){var o,u,p=a(t,r);if(p.oneOf&&(p=i.schema(e,p,r)),p["enum"])o=e||p["enum"][0];else if("object"===p.type){o=s.merge(e);for(u in p.properties)o[u]=n((e||{})[u],p.properties[u],r)}else if("array"===p.type)for(o=[],u=0;u<(e||[]).length;++u)o[u]=n((e||[])[u],p.items,r);else o=e;return o}var s=r(3),i=r(8),a=r(9);e.exports=function(e,t,r){return s.prune(n(e,t,r))}},function(e,t,r){"use strict";var n=r(3),s=function(e,t){var r=[];return null!==e.maximum&&(t>e.maximum?r.push("may be at most "+e.maximum):e.exclusiveMaximum&&t>=e.maximum&&r.push("must be less than "+e.maximum)),null!==e.minimum&&(t<e.minimum?r.push("must be at least "+e.minimum):e.exclusiveMinimum&&t<=e.minimum&&r.push("must be more than "+e.minimum)),null!=e.multipleOf&&t/e.multipleOf%1!=0&&r.push("must be a multiple of "+e.multipleOf),r},i=function(e){return e.length>0?[{path:[],errors:e}]:[]},a={};a["boolean"]=function(e,t){var r=[];return"boolean"!=typeof t&&r.push("must be boolean"),i(r)},a["enum"]=function(e,t){var r=[];return e["enum"].indexOf(t)<0&&r.push("value not in list"),i(r)},a.number=function(e,t){var r=[];return"number"!=typeof t?r.push("must be a number"):r=s(e,t),i(r)},a.integer=function(e,t){var r=[];return"number"!=typeof t?r.push("must be a number"):(r=s(e,t),t%1>0&&r.unshift("must be an integer")),i(r)},a.string=function(e,t){var r=[];return"string"!=typeof t?r.push("must be a string"):(null!=e.maxLength&&t.length>e.maxLength&&r.push("may have at most "+e.maxLength+" characters"),null!=e.minLength&&t.length<e.minLength&&r.push("must have at least "+e.minLength+" characters"),null==e.pattern||RegExp(e.pattern).test(t)||r.push("must match "+e.pattern)),i(r)},a.array=function(e,t,r){var n,s,a,o=[];if(!Array.isArray(t))return i(["must be an array"]);if(null!=e.maxItems&&t.length>e.maxItems&&o.push("may have at most "+e.maxItems+" items"),null!=e.minItems&&t.length<e.minItems&&o.push("must have at least "+e.minItems+" items"),n=i(o),null!=e.items)for(s in t){o=l(e.items,t[s],r);for(a in o)n.push({path:[s].concat(o[a].path),errors:o[a].errors})}return n};var o=function(e,t){var r;return null!=e.required&&e.required.indexOf(t)>=0?"must be present":(r=e.properties[t],"array"==r.type&&r.minItems>0?"must have at least "+r.minItems+" items":null)};a.object=function(e,t,r){var n,s,i,a=[];if(null==t&&(t={}),t.constructor!==Object)a.push({path:[],errors:["must be a plain object"]});else for(n in e.properties)if(t.hasOwnProperty(n))for(s=l(e.properties[n],t[n],r),i=0;i<s.length;++i)a.push({path:[n].concat(s[i].path),errors:s[i].errors});else o(e,n)&&a.push({path:[n],errors:[o(e,n)]});return a};var u=function(e){return[].concat.apply([],e)},p=function(e,t){var r=e.$ref;if(r){if(!r.match(/^#(\/([a-zA-Z_][a-zA-Z_0-9]*|[0-9]+))*$/))throw new Error("reference "+r+" has unsupported format");return{allOf:[n.without(e,"$ref"),n.getIn(t,r.split("/").slice(1))]}}return e},l=function(e,t,r){var s=r||e,i=p(e,s);if(i.allOf){var o=[n.without(i,"allOf")].concat(i.allOf).map(function(e){return l(e,t,s)});return u(o)}var c=i["enum"]?"enum":i.type;return c?a[c](i,t,s):[]};e.exports=l}])});
\ No newline at end of file
diff --git a/lib/fields/input.js b/lib/fields/input.js
index a8acd06..904c828 100644
--- a/lib/fields/input.js
+++ b/lib/fields/input.js
@@ -1,6 +1,7 @@
 'use strict';
 
 var React = require('react');
+var ou = require('../objectUtils');
 var $ = React.DOM;
 
 var normalizer = require('./utils/normalizer');
@@ -26,10 +27,11 @@ var InputField = React.createClass({
     }
   },
   render: function() {
+    var value = ou.isNil(this.props.value)? '' : this.props.value;
     return $.input({
       type      : "text",
       name      : this.props.label,
-      value     : this.props.value || '',
+      value     : value,
       onKeyPress: this.handleKeyPress,
       onChange  : this.handleChange });
   }
diff --git a/lib/fields/utils/parser.js b/lib/fields/utils/parser.js
index 869176b..f3c07de 100644
--- a/lib/fields/utils/parser.js
+++ b/lib/fields/utils/parser.js
@@ -1,16 +1,16 @@
 'use strict';
 
 var normalizer = require('./normalizer');
-
+var ou = require('../../objectUtils');
 
 exports.string = function(text) {
   return normalizer.string(text);
 };
 
 exports.integer = function(text) {
-  return text ? parseInt(normalizer.integer(text)) : null;
+  return ou.isNil(text) ? null : parseInt(normalizer.integer(text));
 };
 
 exports.number = function(text) {
-  return text ? parseFloat(normalizer.number(text)) : null;
+  return ou.isNil(text) ? null : parseFloat(normalizer.number(text));
 };
diff --git a/lib/objectUtils.js b/lib/objectUtils.js
index 17e444b..be83ab9 100644
--- a/lib/objectUtils.js
+++ b/lib/objectUtils.js
@@ -24,6 +24,10 @@ var isNat = function(x) {
   return typeof x == 'number' && x >= 0 && x % 1 == 0;
 };
 
+var isNil = function(x) {
+  return (typeof x === 'undefined' || x === null);
+};
+
 var object = function() {
   var args = Array.prototype.slice.call(arguments);
   var result = [];
@@ -158,5 +162,6 @@ module.exports = {
   prune  : prune,
   split  : split,
   map    : map,
-  mapKeys: mapKeys
+  mapKeys: mapKeys,
+  isNil  : isNil
 };
diff --git a/lib/validate.js b/lib/validate.js
index 1d80ce8..1406b8a 100644
--- a/lib/validate.js
+++ b/lib/validate.js
@@ -21,7 +21,6 @@ SOFTWARE.
 'use strict';
 
 var ou = require('./objectUtils');
-var alternative = require('./alternative');
 
 var checkNumber = function(schema, instance) {
   var errors = [];
@@ -174,9 +173,6 @@ validator.object = function(schema, instance, context) {
   if (instance == null)
     instance = {};
 
-  var alternativeSchema = alternative.schema(instance, schema, context);
-  schema = alternativeSchema || schema;
-
   if (instance.constructor !== Object)
     result.push({ path: [], errors: ['must be a plain object'] });
   else {