add preserveWhitespace option

Author: yyx990803

src/compiler/codegen.js

@@ -1,3 +1,4 @@
+import config from '../config'
 import { parseText } from './text-parser'
 import { isArray } from '../util/index'
 
@@ -25,7 +26,7 @@ function genElement (el, key) {
 }
 
 function genIf (el, exp) {
-  return `(${exp}) ? ${genElement(el)} : ''`
+  return `(${exp}) ? ${genElement(el)} : null`
 }
 
 function genFor (el, exp) {
@@ -101,7 +102,6 @@ function genData (el, key) {
   if (hasEvents) {
     data += genEvents(events)
   }
-  console.log(data)
   return data.replace(/,$/, '') + '}'
 }
 

src/compiler/html-parser.js

@@ -1,3 +1,5 @@
+import config from '../config'
+
 /**
  * Convert HTML string to AST
  *
@@ -37,8 +39,14 @@ export function parse (html) {
     chars (text) {
       text = currentParent.tag === 'pre'
         ? text
-        : text.trim() ? text : ' '
-      currentParent.children.push(text)
+        : text.trim()
+          ? text
+          : config.preserveWhiteSpace
+            ? ' '
+            : null
+      if (text) {
+        currentParent.children.push(text)
+      }
     }
   })
   return root

src/config.js

@@ -1,13 +1,10 @@
 export default {
 
   /**
-   * Whether to print debug messages.
-   * Also enables stack trace for warnings.
-   *
-   * @type {Boolean}
+   * Preserve whitespaces between elements.
    */
 
-  debug: false,
+  preserveWhiteSpace: true,
 
   /**
    * Whether to suppress warnings.
@@ -17,35 +14,13 @@ export default {
 
   silent: false,
 
-  /**
-   * Whether to use async rendering.
-   */
-
-  async: true,
-
   /**
    * Whether to warn against errors caught when evaluating
    * expressions.
    */
 
   warnExpressionErrors: true,
 
-  /**
-   * Whether to allow devtools inspection.
-   * Disabled by default in production builds.
-   */
-
-  devtools: process.env.NODE_ENV !== 'production',
-
-  /**
-   * Internal flag to indicate the delimiters have been
-   * changed.
-   *
-   * @type {Boolean}
-   */
-
-  _delimitersChanged: true,
-
   /**
    * List of asset types that a component can own.
    *