Number editor return number. (#541)

Adding support for `min`, `max`, `step` on the input element and adding
`valueType` for specifying the return type, so the `NumberControl` can
return actual numbers.

src/components/Widgets/NumberControl.js

@@ -1,17 +1,41 @@
 import React, { PropTypes } from 'react';
 
-export default class StringControl extends React.Component {
+export default class NumberControl extends React.Component {
   handleChange = (e) => {
-    this.props.onChange(e.target.value);
+    const valueType = this.props.field.get('valueType');
+    const { onChange } = this.props;
+    if(valueType === 'int') {
+      onChange(parseInt(e.target.value, 10));
+    } else if(valueType === 'float') {
+      onChange(parseFloat(e.target.value));
+    } else {
+      onChange(e.target.value);
+    }
   };
 
   render() {
-    return <input type="number" id={this.props.forID} value={this.props.value || ''} onChange={this.handleChange} />;
+    const { field, value, forID } = this.props;
+    const min = field.get('min', '');
+    const max = field.get('max', '');
+    const step = field.get('step', field.get('valueType') === 'int' ? 1 : '');
+    return <input
+      type="number"
+      id={forID}
+      value={value || ''}
+      step={step}
+      min={min}
+      max={max}
+      onChange={this.handleChange}
+    />;
   }
 }
 
-StringControl.propTypes = {
+NumberControl.propTypes = {
   onChange: PropTypes.func.isRequired,
   value: PropTypes.node,
   forID: PropTypes.string,
+  valueType: PropTypes.string,
+  step: PropTypes.number,
+  min: PropTypes.number,
+  max: PropTypes.number,
 };