Support response data streaming and add an example file downloader.

examples/CMakeLists.txt

@@ -62,5 +62,8 @@ target_link_libraries(file_upload_server ${EXAMPLE_LIBS})
 add_executable(file_server file_server.cc)
 target_link_libraries(file_server ${EXAMPLE_LIBS})
 
+add_executable(file_downloader file_downloader.cc)
+target_link_libraries(file_downloader ${EXAMPLE_LIBS})
+
 add_executable(server_states server_states.cc)
 target_link_libraries(server_states ${EXAMPLE_LIBS})

examples/file_downloader.cc

@@ -0,0 +1,44 @@
+// Download files.
+// This example demonstrates the usage of streamed response.
+
+#include <iostream>
+
+#include "webcc/client_session.h"
+#include "webcc/logger.h"
+
+void Help(const char* argv0) {
+  std::cout << "Usage: file_downloader <url> <path>" << std::endl;
+  std::cout << "E.g.," << std::endl;
+  std::cout << "    file_downloader http://httpbin.org/image/jpeg D:/test.jpg"
+            << std::endl;
+  std::cout << "    file_downloader https://www.google.com/favicon.ico"
+            << " D:/test.ico" << std::endl;
+}
+
+int main(int argc, char* argv[]) {
+  if (argc != 3) {
+    Help(argv[0]);
+    return 1;
+  }
+
+  std::string url = argv[1];
+  std::string path = argv[2];
+
+  WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
+
+  webcc::ClientSession session;
+
+  try {
+    auto r = session.Request(webcc::RequestBuilder{}.Get(url)(),
+                             true);  // Stream the response data to file.
+
+    auto file_body = r->file_body();
+
+    file_body->Move(path);
+
+  } catch (const std::exception& e) {
+    std::cerr << e.what() << std::endl;
+  }
+
+  return 0;
+}