feat: add page streaming for php (#3318)

src/main/java/com/google/api/codegen/config/PageStreamingConfig.java

@@ -246,8 +246,10 @@ static PageStreamingConfig createPageStreamingConfig(
     if (pageSizeField == null) {
       // TODO: Conform to design doc spec, once approved, for using non-standard paging fields
       //       (such as max_results for page_size)
-      if (language == TargetLanguage.JAVA && transportProtocol == TransportProtocol.HTTP) {
-        pageSizeField = methodModel.getInputField(pagingParams.getNameForMaxResults());
+      if (transportProtocol == TransportProtocol.HTTP) {
+        if (language == TargetLanguage.JAVA || language == TargetLanguage.PHP) {
+          pageSizeField = methodModel.getInputField(pagingParams.getNameForMaxResults());
+        }
       }
     }
     ProtoField responseTokenField =

src/main/java/com/google/api/codegen/transformer/php/PhpGapicSurfaceTransformer.java

@@ -65,6 +65,7 @@
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -206,7 +207,7 @@ private ViewModel buildGapicClientViewModel(GapicInterfaceContext context) {
     } else {
       // PHP generates a client that only supports REST
       apiImplClass.grpcClientTypeName("");
-      apiImplClass.stubs(new ArrayList<>());
+      apiImplClass.stubs(Collections.emptyList());
     }
 
     apiImplClass.apiMethods(methods.stream().collect(Collectors.toList()));

src/main/resources/com/google/api/codegen/php/test.snip

@@ -308,7 +308,11 @@
         @join pageStreamingResponseView : test.pageStreamingResponseViews
             ${@pageStreamingResponseView.resourcesVarName} = iterator_to_array($response->{@pageStreamingResponseView.resourcesIterateMethod}());
             $this->assertSame(1, count(${@pageStreamingResponseView.resourcesVarName}));
-            $this->assertEquals($expectedResponse->{@pageStreamingResponseView.resourcesFieldGetterName}()[0], ${@pageStreamingResponseView.resourcesVarName}[0]);
+            @if pageStreamingResponseView.resourcesFieldIsMap
+                {@mapFieldPageStreamingAsserts(pageStreamingResponseView, test.mockResponse.rpcResponseInitCode)}
+            @else
+                $this->assertEquals($expectedResponse->{@pageStreamingResponseView.resourcesFieldGetterName}()[0], ${@pageStreamingResponseView.resourcesVarName}[0]);
+            @end
         @end
 
         {@singleCallSuccessAsserts(test)}
@@ -553,3 +557,16 @@
         @end
     @end
 @end
+
+@private mapFieldPageStreamingAsserts(view, initCode)
+    @join line : initCode.lines
+        @if line.lineType == "MapInitLine"
+            @join mapEntry : line.initEntries on ","
+                $this->assertArrayHasKey({@mapEntry.key}, $expectedResponse->{@view.resourcesFieldGetterName}());
+                $this->assertArrayHasKey({@mapEntry.key}, ${@view.resourcesVarName});
+                $this->assertEquals($expectedResponse->{@view.resourcesFieldGetterName}()[{@mapEntry.key}], ${@view.resourcesVarName}[{@mapEntry.key}]);
+            @end
+        @end
+    @end
+@end
+

src/test/java/com/google/api/codegen/protoannotations/testdata/php_library_rest.baseline

@@ -1016,7 +1016,22 @@ class LibraryServiceGapicClient
      * ```
      * $libraryServiceClient = new LibraryServiceClient();
      * try {
-     *     $response = $libraryServiceClient->listAggregatedShelves();
+     *     // Iterate over pages of elements
+     *     $pagedResponse = $libraryServiceClient->listAggregatedShelves();
+     *     foreach ($pagedResponse->iteratePages() as $page) {
+     *         foreach ($page as $element) {
+     *             // doSomethingWith($element);
+     *         }
+     *     }
+     *
+     *
+     *     // Alternatively:
+     *
+     *     // Iterate through all elements
+     *     $pagedResponse = $libraryServiceClient->listAggregatedShelves();
+     *     foreach ($pagedResponse->iterateAllElements() as $element) {
+     *         // doSomethingWith($element);
+     *     }
      * } finally {
      *     $libraryServiceClient->close();
      * }
@@ -1025,17 +1040,22 @@ class LibraryServiceGapicClient
      * @param array $optionalArgs {
      *     Optional.
      *     @type int $maxResults
-     *          Requested page size.
+     *          The maximum number of resources contained in the underlying API
+     *          response. The API may return fewer values in a page, even if
+     *          there are additional values to be retrieved.
      *     @type string $pageToken
-     *          A token identifying a page of results the server should return.
+     *          A page token is used to specify a page of values to be returned.
+     *          If no page token is specified (the default), the first page
+     *          of values will be returned. Any page token used here must have
+     *          been generated by a previous call to the API.
      *     @type RetrySettings|array $retrySettings
      *          Retry settings to use for this call. Can be a
      *          {@see Google\ApiCore\RetrySettings} object, or an associative array
      *          of retry settings parameters. See the documentation on
      *          {@see Google\ApiCore\RetrySettings} for example usage.
      * }
      *
-     * @return \Google\Example\Library\V1\ListAggregatedShelvesResponse
+     * @return \Google\ApiCore\PagedListResponse
      *
      * @throws ApiException if the remote call fails
      * @experimental
@@ -1050,12 +1070,12 @@ class LibraryServiceGapicClient
             $request->setPageToken($optionalArgs['pageToken']);
         }
 
-        return $this->startCall(
+        return $this->getPagedListResponse(
             'ListAggregatedShelves',
-            ListAggregatedShelvesResponse::class,
             $optionalArgs,
+            ListAggregatedShelvesResponse::class,
             $request
-        )->wait();
+        );
     }
 
     /**
@@ -3570,6 +3590,16 @@ return [
                     'totalPollTimeoutMillis' => '300000',
                 ]
             ],
+            'ListAggregatedShelves' => [
+                'pageStreaming' => [
+                    'requestPageTokenGetMethod' => 'getPageToken',
+                    'requestPageTokenSetMethod' => 'setPageToken',
+                    'requestPageSizeGetMethod' => 'getMaxResults',
+                    'requestPageSizeSetMethod' => 'setMaxResults',
+                    'responsePageTokenGetMethod' => 'getNextPageToken',
+                    'resourcesGetMethod' => 'getShelves'
+                ]
+            ],
             'ListBooks' => [
                 'pageStreaming' => [
                     'requestPageTokenGetMethod' => 'getPageToken',
@@ -4052,6 +4082,7 @@ use Google\Example\Library\V1\GetShelfRequest;
 use Google\Example\Library\V1\Inventory;
 use Google\Example\Library\V1\ListAggregatedShelvesRequest;
 use Google\Example\Library\V1\ListAggregatedShelvesResponse;
+use Google\Example\Library\V1\ListAggregatedShelvesResponse\ShelvesEntry;
 use Google\Example\Library\V1\ListBooksRequest;
 use Google\Example\Library\V1\ListBooksResponse;
 use Google\Example\Library\V1\ListShelvesRequest;
@@ -4365,20 +4396,31 @@ class LibraryServiceClientTest extends GeneratedTest
         $this->assertTrue($transport->isExhausted());
 
         // Mock response
-        $nextPageToken = 'nextPageToken-1530815211';
+        $nextPageToken = '';
+        $shelvesItem = new Shelf();
+        $shelves = ['shelves' => $shelvesItem];
         $expectedResponse = new ListAggregatedShelvesResponse();
         $expectedResponse->setNextPageToken($nextPageToken);
+        $expectedResponse->setShelves($shelves);
         $transport->addResponse($expectedResponse);
 
         $response = $client->listAggregatedShelves();
-        $this->assertEquals($expectedResponse, $response);
+        $this->assertEquals($expectedResponse, $response->getPage()->getResponseObject());
+        $resources = iterator_to_array($response->iterateAllElements());
+        $this->assertSame(1, count($resources));
+
+
+        $this->assertArrayHasKey('shelves', $expectedResponse->getShelves());
+        $this->assertArrayHasKey('shelves', $resources);
+        $this->assertEquals($expectedResponse->getShelves()['shelves'], $resources['shelves']);
+
+
         $actualRequests = $transport->popReceivedCalls();
         $this->assertSame(1, count($actualRequests));
         $actualFuncCall = $actualRequests[0]->getFuncCall();
         $actualRequestObject = $actualRequests[0]->getRequestObject();
         $this->assertSame('/google.example.library.v1.LibraryService/ListAggregatedShelves', $actualFuncCall);
 
-
         $this->assertTrue($transport->isExhausted());
     }