[Fetch API] Implement Request.formData and Response.formData.

third_party/WebKit/Source/modules/fetch/Body.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/fetch/Body.h"
 
 #include <memory>
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/V8ArrayBuffer.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/dom/URLSearchParams.h"
 #include "core/fileapi/Blob.h"
+#include "core/html/FormData.h"
 #include "modules/fetch/BodyStreamBuffer.h"
 #include "modules/fetch/FetchDataLoader.h"
 #include "platform/bindings/ScriptState.h"
 #include "platform/bindings/V8ThrowException.h"
+#include "platform/network/ParsedContentType.h"
 #include "platform/wtf/PassRefPtr.h"
 #include "platform/wtf/RefPtr.h"
 #include "public/platform/WebDataConsumerHandle.h"
 
 namespace blink {
 
 namespace {
 
 class BodyConsumerBase : public GarbageCollectedFinalized<BodyConsumerBase>,
                          public FetchDataLoader::Client {
@@ skipping 37 matching lines @@
 
  public:
   explicit BodyArrayBufferConsumer(ScriptPromiseResolver* resolver)
       : BodyConsumerBase(resolver) {}
 
   void DidFetchDataLoadedArrayBuffer(DOMArrayBuffer* array_buffer) override {
     Resolver()->Resolve(array_buffer);
   }
 };
 
+class BodyFormDataConsumer final : public BodyConsumerBase {
+  WTF_MAKE_NONCOPYABLE(BodyFormDataConsumer);
+
+ public:
+  explicit BodyFormDataConsumer(ScriptPromiseResolver* resolver)
+      : BodyConsumerBase(resolver) {}
+
+  void DidFetchDataLoadedFormData(FormData* formData) override {
+    Resolver()->Resolve(formData);
+  }
+
+  void DidFetchDataLoadedString(const String& string) override {
+    FormData* formData = FormData::Create();
+    for (const auto& pair : URLSearchParams::Create(string)->Params())
+      formData->append(pair.first, pair.second);
+    DidFetchDataLoadedFormData(formData);
+  }
+};
+
 class BodyTextConsumer final : public BodyConsumerBase {
   WTF_MAKE_NONCOPYABLE(BodyTextConsumer);
 
  public:
   explicit BodyTextConsumer(ScriptPromiseResolver* resolver)
       : BodyConsumerBase(resolver) {}
 
   void DidFetchDataLoadedString(const String& string) override {
     Resolver()->Resolve(string);
   }
@@ skipping 66 matching lines @@
         new BodyBlobConsumer(resolver));
   } else {
     std::unique_ptr<BlobData> blob_data = BlobData::Create();
     blob_data->SetContentType(MimeType());
     resolver->Resolve(
         Blob::Create(BlobDataHandle::Create(std::move(blob_data), 0)));
   }
   return promise;
 }
 
+ScriptPromise Body::formData(ScriptState* script_state) {
+  ScriptPromise promise = RejectInvalidConsumption(script_state);
+  if (!promise.IsEmpty())
+    return promise;
+
+  // See above comment.
+  if (!ExecutionContext::From(script_state))
+    return ScriptPromise();
+
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::Create(script_state);
+  const ParsedContentType parsedTypeWithParameters(ContentType());
+  const String parsedType = parsedTypeWithParameters.MimeType().LowerASCII();
+  promise = resolver->Promise();
+  if (parsedType == "multipart/form-data") {
+    const String boundary =
+        parsedTypeWithParameters.ParameterValueForName("boundary");
+    if (BodyBuffer() && !boundary.IsEmpty()) {
+      BodyBuffer()->StartLoading(
+          FetchDataLoader::CreateLoaderAsFormData(boundary),
+          new BodyFormDataConsumer(resolver));
+      return promise;
+    }
+  } else if (parsedType == "application/x-www-form-urlencoded") {
+    if (BodyBuffer()) {
+      BodyBuffer()->StartLoading(FetchDataLoader::CreateLoaderAsString(),
+                                 new BodyFormDataConsumer(resolver));
+    } else {
+      resolver->Resolve(FormData::Create());
+    }
+    return promise;
+  } else {
+    // "Let |reader| be the result of getting reader from |stream|."
+    // "Read all bytes from |stream| with |reader|."
+    if (BodyBuffer())
+      BodyBuffer()->CloseAndLockAndDisturb();

[yhirano, 2017/05/12 11:54:12]

This is not spec-conformant when BodyBuffer() is made from a ReadableStream -
The underlying source of the stream can detect that we don't read the content at
all.

[e_hakkinen, 2017/05/12 14:56:12]

OK. I used the same code as blink::Request::CreateRequestWithRequestOrString
does. But I'll replace that with a null data loader.

[yhirano, 2017/05/15 11:54:48]

Please note that "the same code" in Request::CreateRequestWithRequestOrString is
valid because the BodyStreamBuffer is created from a BytesConsumer.

+  }
+
+  resolver->Reject(V8ThrowException::CreateTypeError(script_state->GetIsolate(),
+                                                     "Invalid MIME type"));
+  return promise;
+}
+
 ScriptPromise Body::json(ScriptState* script_state) {
   ScriptPromise promise = RejectInvalidConsumption(script_state);
   if (!promise.IsEmpty())
     return promise;
 
   // See above comment.
   if (!ExecutionContext::From(script_state))
     return ScriptPromise();
 
   ScriptPromiseResolver* resolver = ScriptPromiseResolver::Create(script_state);
@@ skipping 56 matching lines @@
 
 ScriptPromise Body::RejectInvalidConsumption(ScriptState* script_state) {
   if (IsBodyLocked() || bodyUsed())
     return ScriptPromise::Reject(
         script_state, V8ThrowException::CreateTypeError(
                           script_state->GetIsolate(), "Already read"));
   return ScriptPromise();
 }
 
 }  // namespace blink