Refactor search API. Make up a SearchResults class to collect both search result and promotion. TO prepare for #6

Author: guojiex

lib/search_data_source.dart

@@ -49,9 +49,26 @@ class SearchResult {
           : result.image.contextLink.hashCode;
 }
 
+class Promotion {
+  final customsearch.Promotion promotion;
+
+  Promotion(this.promotion);
+}
+
+/// A wrapper class to aggregate all the search result fields that we need.
+class SearchResults {
+  List<SearchResult> searchResults;
+  List<Promotion> promotions;
+
+  SearchResults({this.searchResults, this.promotions}) {
+    this.searchResults ??= List<SearchResult>();
+    this.promotions ??= List<Promotion>();
+  }
+}
+
 /// Abstract class for Search Data Source.
 abstract class SearchDataSource {
-  Future<List<SearchResult>> search(String query, {String searchType});
+  Future<SearchResults> search(String query, {String searchType});
 }
 
 class _StaticSearchResponse {
@@ -63,9 +80,7 @@ class _StaticSearchResponse {
       {this.assetPath, this.searchType, this.searchResponseJsonString});
 }
 
-
 class FakeSearchDataSource implements SearchDataSource {
-
   final Map<String, _StaticSearchResponse> searchResponses = {
     'web': _StaticSearchResponse(
         assetPath: 'res/sampledata/nytimes_sample_data.json'),
@@ -76,7 +91,6 @@ class FakeSearchDataSource implements SearchDataSource {
         assetPath: 'res/sampledata/nytimes_with_promotion.json'),
   };
 
-
   FakeSearchDataSource() {
     searchResponses.keys.forEach((key) {
       loadAssetToSearchResponse(key, searchResponses[key].assetPath);
@@ -89,19 +103,20 @@ class FakeSearchDataSource implements SearchDataSource {
   }
 
   @override
-  Future<List<SearchResult>> search(String query, {String searchType}) async {
-    var results = List<SearchResult>();
+  Future<SearchResults> search(String query, {String searchType}) async {
     if (!searchResponses.containsKey(query)) {
-      return results;
+      return SearchResults();
     }
     if (searchResponses[query].searchType != searchType) {
-      return results;
+      return SearchResults();
     }
+    var results = List<SearchResult>();
     Map searchMap = jsonDecode(searchResponses[query].searchResponseJsonString);
     customsearch.Search search = customsearch.Search.fromJson(searchMap);
     search.items.forEach(
             (item) => results.add(SearchResult.escapeLineBreakInSnippet(item)));
-    return Set<SearchResult>.from(results).toList();
+    return SearchResults(
+        searchResults: Set<SearchResult>.from(results).toList());
   }
 }
 
@@ -117,14 +132,15 @@ class CustomSearchDataSource implements SearchDataSource {
   }
 
   @override
-  Future<List<SearchResult>> search(String query, {String searchType}) async {
+  Future<SearchResults> search(String query, {String searchType}) async {
     var results = List<SearchResult>();
     customsearch.Search search =
         await this.api.cse.list(query, cx: this.cx, searchType: searchType);
     if (search.items != null) {
       search.items.forEach((item) => results.add(SearchResult(item)));
     }
-    return Set<SearchResult>.from(results).toList();
+    return SearchResults(
+        searchResults: Set<SearchResult>.from(results).toList());
   }
 }
 

lib/search_result_page.dart

@@ -253,12 +253,11 @@ class CustomSearchSearchDelegate extends SearchDelegate<SearchResult> {
 
   @override
   Widget buildResults(BuildContext context) {
-    return FutureBuilder<List<SearchResult>>(
+    return FutureBuilder<SearchResults>(
       future: dataSource.search(query,
           searchType: this.searchType == SearchType.web ? null : 'image'),
       // a previously-obtained Future<List<SearchResult>> or null
-      builder:
-          (BuildContext context, AsyncSnapshot<List<SearchResult>> snapshot) {
+      builder: (BuildContext context, AsyncSnapshot<SearchResults> snapshot) {
         switch (snapshot.connectionState) {
           case ConnectionState.none:
             return Text('Press button to start.');
@@ -274,18 +273,18 @@ class CustomSearchSearchDelegate extends SearchDelegate<SearchResult> {
                     mainAxisSpacing: 4.0,
                     crossAxisSpacing: 4.0,
                     padding: const EdgeInsets.all(4.0),
-                    children: List.generate(snapshot.data.length, (index) {
+                    children: List.generate(snapshot.data.searchResults.length,
+                            (index) {
                       return new ImageSearchResultCard(
-                          searchResult: snapshot.data[index],
+                          searchResult: snapshot.data.searchResults[index],
                           searchDelegate: this);
                     }));
               case SearchType.web:
-                print(snapshot.data.length);
                 return ListView.builder(
-                    itemCount: snapshot.data.length,
+                    itemCount: snapshot.data.searchResults.length,
                     itemBuilder: (BuildContext context, int index) {
                       return new WebSearchResultCard(
-                          searchResult: snapshot.data[index],
+                          searchResult: snapshot.data.searchResults[index],
                           searchDelegate: this);
                     });
               default:

test/search_data_source_test.dart

@@ -8,8 +8,8 @@ void main() {
         .readAsString()
         .then((String contents) {
       var dataSource = FakeSearchDataSource();
-      dataSource.search('whatever').then((searchResult) {
-        searchResult.forEach((result) => print(result));
+      dataSource.search('whatever').then((searchResults) {
+        searchResults.searchResults.forEach((result) => print(result));
       });
     });
   });