品类下拉刷新优化 review by chenlin

@@ -89,7 +89,12 @@ class CategoryBContainer extends Component {
     _onSelectChannel(channel) {
         this.props.actions.setCurrentChannelB(channel.id, channel.value);
 
-        let category = this.props.categoryB.categoryList.get(channel.value).get(0);
+        let list = this.props.categoryB.categoryList.get(channel.value);
+        if (!list || list.size == 0) {
+            return;
+        }
+
+        let category = list.get(0);
         category && this._onSelectCategory(category.toJS());
     }
 

@@ -67,7 +67,7 @@ export function pressCategoryBMore(category_id){
         };
 
         //设置当前的类别信息
-    	dispatch(setCurrentCateB(category_id, category ? category.get('category_name') : ""));
+    	// dispatch(setCurrentCateB(category_id, category ? category.get('category_name') : ""));
         dispatch(jumpToCategory(all, 0, categoryB.currentChannelId));
         
 	};
@@ -89,12 +89,12 @@ export function fetchSubCategory(categoryId, categoryValue, callback) {
 		//检查缓存是否存在数据，如果不存在则获取
 	    let key = getSubDetailCacheKey(currentChannelId, categoryId);
 	    let categoryData = cacheSubCateData ? cacheSubCateData.get(key) : "";
-	    //未命中，访问网络数据
+	    //已命中，展示缓存数据
 	    if (categoryData) {
 	        dispatch(getCategoryBSubDetailFromCache(categoryData));
 	        //曝光从缓存获取的数据
 	        dispatch(dataExposure(currentChannelId, categoryId, categoryValue, categoryData));
-	    //已命中，展示缓存数据
+	    //未命中，访问网络数据
 	    } else {
 	    	callback && callback();
 	    }
@@ -104,24 +104,38 @@ export function fetchSubCategory(categoryId, categoryValue, callback) {
 /**
  * 获取子分类的数据，逻辑上先判断缓存数据是否存在，不存在则从网络获取
  **/
-export function getCategoryBSubCategoryDetail(category_id, category_value){
+export function getCategoryBSubCategoryDetail(categoryId, categoryValue){
 
 	return (dispatch, getState) => {
 
 		let {categoryB} = getState();
 
 		let {
+			currentChannelId,
             currentCateId,
             currentCateValue,
+            cacheSubCateData,
         } = categoryB;
 
+        //检查缓存是否存在数据
+	    let key = getSubDetailCacheKey(currentChannelId, categoryId);
+	    let categoryData = cacheSubCateData ? cacheSubCateData.get(key) : "";
+	    //已有缓存
+	    if (categoryData && categoryData.size > 0) {
+	    	let lastTimestamp = categoryData.get('lrts', 0);
+	    	let currentTimestamp = new Date().getTime();
+	    	let diff = currentTimestamp - lastTimestamp;
+	    	if (diff < 250) {
+	    		__DEV__ && console.log('timestamp diff < 50, return');
+	    		return;
+	    	}
+	    }
 
-		if (currentCateId == category_id && categoryB.contentFetching) {
+		if (currentCateId == categoryId && categoryB.contentFetching) {
 			return;
 		}
 
-		let currentChannelId = categoryB.currentChannelId;
-        dispatch(getCategoryBSubDetail(currentChannelId, category_id, category_value));
+        dispatch(getCategoryBSubDetail(currentChannelId, categoryId, categoryValue));
 	};
 }
 
@@ -182,7 +196,11 @@ export function getCategoryBFirstSubCategoryDetail() {
 
 	return (dispatch, getState) => {
 		let {categoryB} = getState();
-		let {currentChannelId, currentChannelValue, categoryList} = categoryB;
+		let {currentChannelId, currentChannelValue, categoryList, contentFetching} = categoryB;
+		if (contentFetching) {
+			return;
+		}
+
 		let category = categoryList.get(currentChannelValue) ? categoryList.get(currentChannelValue).get(0) : "";
 
 		let category_id = category ? category.get('category_id') : "";
@@ -203,7 +221,7 @@ function parseCategoryBSubDetail(channel_id, category_id, subcategory_data, prop
 	if(!subcategory_data || !props_data){
 		return;
 	}
-
+	subcategory_data.lrts = new Date().getTime();
 	let key = getSubDetailCacheKey(channel_id, category_id);
 
 	return {key: key, data: subcategory_data};