* [WEEX-313][iOS]fix RTL issue

ios/sdk/WeexSDK/Sources/Component/WXTextComponent.h

@@ -24,4 +24,5 @@
 
 + (void)setRenderUsingCoreText:(BOOL)usingCoreText;
 - (BOOL)useCoreText;
+
 @end

ios/sdk/WeexSDK/Sources/Component/WXTextComponent.m

@@ -481,7 +481,7 @@ - (NSMutableAttributedString *)buildCTAttributeString
     NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];
 
     // handle text direction style, default ltr
-    if ([_direction isEqualToString:@"rtl"]) {
+    if (_cssNode->layout.direction == CSS_DIRECTION_RTL) {
         if (0 == _textAlign) {
             //force text right-align if don't specified any align.
             _textAlign = NSTextAlignmentRight;
@@ -563,7 +563,7 @@ - (NSAttributedString *)buildAttributeString
     NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];
 
     // handle text direction style, default ltr
-    if ([_direction isEqualToString:@"rtl"]) {
+    if (_cssNode->layout.direction == CSS_DIRECTION_RTL) {
         if (0 == _textAlign) {
             //force text right-align if don't specified any align.
             _textAlign = NSTextAlignmentRight;

ios/sdk/WeexSDK/Sources/Layout/Layout.c

@@ -1324,4 +1324,6 @@ void resetNodeLayout(css_node_t *node) {
   node->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
   node->layout.position[CSS_LEFT] = 0;
   node->layout.position[CSS_TOP] = 0;
+  node->layout.position[CSS_RIGHT] = 0;
+  node->layout.position[CSS_BOTTOM] = 0;
 }

ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.m

@@ -37,30 +37,13 @@ @implementation WXComponent (Layout)
 
 - (void)setNeedsLayout
 {
+    _isLayoutDirty = YES;
     WXComponent *supercomponent = [self supercomponent];
-    if (self->_virtualComponentId || self->_templateComponent) {
-        // we will generate a virtualComponentId for recycleList virtual component or templateComponent for recycleList component template.
-        // as for recyclelist component, it depends on the input data, not the new layout, here will not try to clear slibling child layout.
-        _isLayoutDirty = YES;
+    if(supercomponent){
         [supercomponent setNeedsLayout];
-    } else {
-        if(supercomponent){
-            for (WXComponent *siblingComponent in [supercomponent subcomponents]) {
-                [siblingComponent _needRecalculateLayout];
-            }
-            [supercomponent setNeedsLayout];
-        } else {
-            [self _needRecalculateLayout];
-        }
     }
 }
 
-- (void)_needRecalculateLayout
-{
-    _isLayoutDirty = YES;
-    [self _clearLayoutCSS];
-}
-
 - (BOOL)needsLayout
 {
     return _isLayoutDirty;
@@ -234,23 +217,6 @@ - (void)_layoutDidFinish
     [self layoutDidFinish];
 }
 
-/**
- * clear the layout variables on css node
- **/
-- (void)_clearLayoutCSS {
-    memset(&(_cssNode->layout), 0, sizeof(_cssNode->layout));
-    _cssNode->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
-    _cssNode->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
-
-    // Such that the comparison is always going to be false
-    _cssNode->layout.last_requested_dimensions[CSS_WIDTH] = -1;
-    _cssNode->layout.last_requested_dimensions[CSS_HEIGHT] = -1;
-    _cssNode->layout.last_parent_max_width = -1;
-    _cssNode->layout.last_parent_max_height = -1;
-    _cssNode->layout.last_direction = (css_direction_t)-1;
-    _cssNode->layout.should_update = true;
-}
-
 #define WX_STYLE_FILL_CSS_NODE(key, cssProp, type)\
 do {\
     id value = styles[@#key];\