Added a method to perform POST Form Upload

README.md

@@ -29,6 +29,25 @@ RestClient::Response r = RestClient::put("http://url.com/put", "application/json
 RestClient::Response r = RestClient::patch("http://url.com/patch", "application/json", "{\"foo\": \"bla\"}")
 RestClient::Response r = RestClient::del("http://url.com/delete")
 RestClient::Response r = RestClient::head("http://url.com")
+
+// Post Form Upload
+/* Filling information about the form in a RestClient::PostFormInfo object */
+RestClient::PostFormInfo uploadInfo;
+/* "submitted" is the name of the "file" input and "TestPostForm.txt"
+is the location of the file to submit.
+<input type="file" name="submitted">
+*/
+uploadInfo.addFormFile("submitted", "TestPostForm.txt");
+/* In some rare cases, some fields related to the form can be filled with
+addFormContent(), the 1st argument is the name of the input element and
+the 2nd argument is the value assigned to it.
+<input type="text" name="filename" value=""/>
+<input type="submit" name="submit" value="send">
+*/
+uploadInfo.addFormContent("filename", "myfile.cpp");
+uploadInfo.addFormContent("submit", "send");
+/* Performing a post form upload with the information provided above */
+RestClient::Response res = RestClient::postForm("http://posttestserver.com/post.php?dir=restclientcpptests", uploadInfo);
 RestClient::Response r = RestClient::options("http://url.com")
 ```
 

include/restclient-cpp/connection.h

@@ -188,6 +188,8 @@ class Connection {
     RestClient::Response get(const std::string& uri);
     RestClient::Response post(const std::string& uri,
                               const std::string& data);
+    RestClient::Response postForm(const std::string& uri,
+                                  const PostFormInfo& data);
     RestClient::Response put(const std::string& uri,
                              const std::string& data);
     RestClient::Response patch(const std::string& uri,

include/restclient-cpp/helpers.h

@@ -9,6 +9,8 @@
 #ifndef INCLUDE_RESTCLIENT_CPP_HELPERS_H_
 #define INCLUDE_RESTCLIENT_CPP_HELPERS_H_
 
+#include <curl/curl.h>
+
 #include <string>
 #include <cctype>
 #include <algorithm>

include/restclient-cpp/restclient.h

@@ -13,6 +13,7 @@
 #include <map>
 #include <cstdlib>
 
+#include "restclient-cpp/helpers.h"
 #include "restclient-cpp/version.h"
 
 /**
@@ -40,6 +41,26 @@ typedef struct {
   HeaderFields headers;
 } Response;
 
+/** @class PostFormInfo
+  * @brief This class represents the form information to send on
+  * POST Form requests
+  */
+class PostFormInfo {
+  struct curl_httppost* formPtr;
+  struct curl_httppost* lastFormPtr;
+ public:
+  PostFormInfo();
+  ~PostFormInfo();
+  /* Fill in the file upload field */
+  void addFormFile(const std::string& fieldName,
+                   const std::string& fieldValue);
+  /* Fill in the filename or the submit field */
+  void addFormContent(const std::string& fieldName,
+                        const std::string& fieldValue);
+  /* Get Form pointer */
+  struct curl_httppost* GetFormPtr() const { return formPtr; }
+};
+
 // init and disable functions
 int init();
 void disable();
@@ -53,6 +74,8 @@ Response get(const std::string& url);
 Response post(const std::string& url,
               const std::string& content_type,
               const std::string& data);
+Response postForm(const std::string& url,
+                  const PostFormInfo& data);
 Response put(const std::string& url,
               const std::string& content_type,
               const std::string& data);

source/connection.cc

@@ -470,6 +470,26 @@ RestClient::Connection::post(const std::string& url,
 
   return this->performCurlRequest(url);
 }
+/**
+ * @brief HTTP POST Form method
+ *
+ * @param url to query
+ * @param data form info
+ *
+ * @return response struct
+ */
+RestClient::Response
+RestClient::Connection::postForm(const std::string& url,
+                             const PostFormInfo& data) {
+  /** Now specify we want to POST data */
+  curl_easy_setopt(this->curlHandle, CURLOPT_POST, 1L);
+  /* stating that Expect: 100-continue is not wanted */
+  AppendHeader("Expect", "");
+  /** set post form */
+  curl_easy_setopt(this->curlHandle, CURLOPT_HTTPPOST, data.GetFormPtr());
+
+  return this->performCurlRequest(url);
+}
 /**
  * @brief HTTP PUT method
  *

source/helpers.cc

@@ -36,6 +36,7 @@ size_t RestClient::Helpers::write_callback(void *data, size_t size,
  * @param size of data
  * @param nmemb memblock
  * @param userdata pointer to user data object to save headr data
+ *
  * @return size * nmemb;
  */
 size_t RestClient::Helpers::header_callback(void *data, size_t size,

source/restclient.cc

@@ -87,6 +87,23 @@ RestClient::Response RestClient::post(const std::string& url,
 #endif
 }
 
+/**
+ * @brief HTTP POST Form method
+ *
+ * @param url to query
+ * @param data post form information
+ *
+ * @return response struct
+ */
+RestClient::Response RestClient::postForm(const std::string& url,
+                    const PostFormInfo& data) {
+  RestClient::Response ret;
+  RestClient::Connection *conn = new RestClient::Connection("");
+  ret = conn->postForm(url, data);
+  delete conn;
+  return ret;
+}
+
 /**
  * @brief HTTP PUT method
  *
@@ -187,3 +204,51 @@ RestClient::Response RestClient::options(const std::string& url) {
   delete conn;
   return ret;
 }
+
+/**
+ * @brief PostFormInfo constructor
+ */
+RestClient::PostFormInfo::PostFormInfo()
+        : formPtr(NULL), lastFormPtr(NULL) {
+}
+
+/**
+ * @brief PostFormInfo destructor
+ */
+RestClient::PostFormInfo::~PostFormInfo() {
+  // cleanup the formpost chain
+  if (this->formPtr) {
+    curl_formfree(this->formPtr);
+    this->formPtr = NULL;
+    this->lastFormPtr = NULL;
+  }
+}
+
+/**
+ * @brief set the name and the value of the HTML "file" form's input
+ *
+ * @param fieldName name of the "file" input
+ * @param fieldValue path to the file to upload
+ */
+void RestClient::PostFormInfo::addFormFile(
+          const std::string& fieldName, const std::string& fieldValue) {
+  curl_formadd(&this->formPtr, &this->lastFormPtr,
+               CURLFORM_COPYNAME, fieldName.c_str(),
+               CURLFORM_FILE, fieldValue.c_str(),
+               CURLFORM_END);
+}
+
+/**
+ * @brief set the name and the value of an HTML form's input 
+ * (other than "file" like "text", "hidden" or "submit")
+ *
+ * @param fieldName name of the input element
+ * @param fieldValue value to be assigned to the input element
+ */
+void RestClient::PostFormInfo::addFormContent(
+          const std::string& fieldName, const std::string& fieldValue) {
+  curl_formadd(&this->formPtr, &this->lastFormPtr,
+               CURLFORM_COPYNAME, fieldName.c_str(),
+               CURLFORM_COPYCONTENTS, fieldValue.c_str(),
+               CURLFORM_END);
+}

test/test_restclient.cc

@@ -1,7 +1,10 @@
 #include "restclient-cpp/restclient.h"
 #include <gtest/gtest.h>
 #include <json/json.h>
+#include <cstdio>
+#include <fstream>
 #include <string>
+#include <sstream>
 
 class RestClientTest : public ::testing::Test
 {
@@ -118,6 +121,37 @@ TEST_F(RestClientTest, TestRestClientPOSTBody)
   EXPECT_EQ("restclient-cpp/" RESTCLIENT_VERSION, root["headers"].get("User-Agent", "no url set").asString());
 }
 
+TEST_F(RestClientTest, TestRestClientPostForm)
+{
+  // generating a file name with a timestamp
+  std::ostringstream fileName;
+  time_t rawtime;
+  tm * timeinfo;
+  time(&rawtime);
+  timeinfo = localtime( &rawtime );
+
+  fileName << "TestPostForm_" << (timeinfo->tm_year)+1900 << "_" << timeinfo->tm_mon+1
+  << "_" << timeinfo->tm_mday << "-" << timeinfo->tm_hour
+  << "_"<< timeinfo->tm_min << "_" << timeinfo->tm_sec << ".txt";
+
+  // creating a dummy file to upload via a post form request
+  std::ofstream ofDummyFile(fileName.str().c_str());
+  ASSERT_TRUE(static_cast<bool>(ofDummyFile));
+  ofDummyFile << "Dummy file for the unit test 'TestRestClientPostForm' of the restclient-cpp Project.";
+  ASSERT_TRUE(static_cast<bool>(ofDummyFile));
+  ofDummyFile.close();
+
+  // uploading the dummy file
+  RestClient::PostFormInfo UploadInfo;
+  UploadInfo.addFormFile("submitted", fileName.str());
+  UploadInfo.addFormContent("filename", fileName.str());
+  RestClient::Response res = RestClient::postForm("http://posttestserver.com/post.php?dir=restclientcpptests", UploadInfo);
+  EXPECT_EQ(200, res.code);
+
+  // remove dummy file
+  remove(fileName.str().c_str());
+}
+
 // check for failure
 TEST_F(RestClientTest, TestRestClientPOSTFailureCode)
 {