Added ability to download json file from an http or https url

Author: beached

CMakeLists.txt

@@ -6,6 +6,8 @@ include( ExternalProject )
 
 find_package( Boost 1.58.0 COMPONENTS system date_time iostreams program_options filesystem regex unit_test_framework REQUIRED )
 
+find_package( CURL )
+
 enable_testing( )
 add_definitions( -DBOOST_TEST_DYN_LINK ) 
 
@@ -57,14 +59,23 @@ externalproject_add(
     CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/install
 )
 
+externalproject_add(
+    temp_file_prj
+    GIT_REPOSITORY "https://github.com/beached/libtemp_file.git"
+    SOURCE_DIR "${CMAKE_BINARY_DIR}/dependencies/temp_file"
+    GIT_TAG "master"
+    INSTALL_DIR "${CMAKE_BINARY_DIR}/install"
+    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/install
+)
+
 set( HEADER_FOLDER "include" )
 set( SOURCE_FOLDER "src" )
 set( TEST_FOLDER "tests" )
 
 include_directories( SYSTEM "${CMAKE_BINARY_DIR}/install/include" )
 include_directories( ${HEADER_FOLDER} )
 include_directories( SYSTEM ${OPENSSL_INCLUDE_DIR} )
-
+include_directories( SYSTEM ${CURL_INCLUDE_DIRS} )
 include_directories( SYSTEM ${Boost_INCLUDE_DIRS} )
 
 link_directories( "${CMAKE_BINARY_DIR}/install/lib" )
@@ -83,7 +94,8 @@ add_dependencies( json_to_cpp header_libraries_prj parse_json_prj char_range_prj
 target_link_libraries( json_to_cpp parse_json tz char_range ${Boost_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT} )
 
 add_executable( json_to_cpp_bin ${HEADER_FILES} ${SOURCE_FOLDER}/main.cpp )
-target_link_libraries( json_to_cpp_bin json_to_cpp parse_json char_range ${Boost_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT} )
+add_dependencies( json_to_cpp_bin temp_file_prj )
+target_link_libraries( json_to_cpp_bin json_to_cpp parse_json char_range temp_file ${Boost_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT} ${CURL_LIBRARIES} )
 
 install( TARGETS json_to_cpp DESTINATION lib )
 install( TARGETS json_to_cpp_bin DESTINATION bin )

src/json_to_cpp.cpp

@@ -191,7 +191,11 @@ namespace daw {
 				val_info_t val_info;
 				val_info.name = "element_" + cur_obj.name;
 				auto const & arry = cur_item.get_array( );
-				val_info.type = arry.front( ).type( );
+				if( arry.empty( ) ) {
+					val_info.type = daw::json::impl::value_t::value_types::null;
+				} else {
+					val_info.type = arry.front( ).type( );
+				}
 				switch( val_info.type ) {
 					case value_t::value_types::array: {
 						obj_state.has_arrays = true;

src/main.cpp

@@ -1,6 +1,6 @@
-// The MIT License (MIT)
+// The MIT License ( MIT )
 //
-// Copyright (c) 2016 Darrell Wright
+// Copyright ( c ) 2016 Darrell Wright
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files( the "Software" ), to deal
@@ -20,26 +20,105 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/optional.hpp>
+#include <boost/utility/string_view.hpp>
 #include <cstdlib>
+#include <curl/curl.h>
 #include <fstream>
+#include <string>
+#include <memory>
 #include <iostream>
 
 #include "json_to_cpp.h"
+namespace {
+	size_t callback( char const * in, size_t const size, size_t const num, std::string * const out ) {
+		assert( out );
+		size_t totalBytes = size * num;
+		out->append( in, totalBytes );
+		return totalBytes;
+	}
+
+	boost::optional<std::string> download( boost::string_view url ) {
+		struct curl_slist *headers = nullptr;
+		curl_slist_append( headers, "Accept: application/json" );  
+		curl_slist_append( headers, "Content-Type: application/json" );
+		curl_slist_append( headers, "charsets: utf-8" ); 
+
+		CURL* curl = curl_easy_init( );
+		if( !curl ) {
+			return boost::none;
+		}
+		curl_easy_setopt( curl, CURLOPT_HTTPHEADER, headers );
+		curl_easy_setopt( curl, CURLOPT_HTTPGET, 1 ); 
+		curl_easy_setopt( curl, CURLOPT_HTTPHEADER, headers); 
+		// Set remote URL.
+		curl_easy_setopt( curl, CURLOPT_URL, url.data( ) );
+
+		// Don't wait forever, time out after 10 seconds.
+		curl_easy_setopt( curl, CURLOPT_TIMEOUT, 15 );
+
+		// Follow HTTP redirects if necessary.
+		curl_easy_setopt( curl, CURLOPT_FOLLOWLOCATION, 1L );
+
+		// Response information.
+		int httpCode = 0;
+		std::string httpData;
+
+		// Hook up data handling function.
+		curl_easy_setopt( curl, CURLOPT_WRITEFUNCTION, callback );
+
+		// Hook up data container ( will be passed as the last parameter to the
+		// callback handling function ).  Can be any pointer type, since it will
+		// internally be passed as a void pointer.
+		curl_easy_setopt( curl, CURLOPT_WRITEDATA, &httpData );
+
+		// Run our HTTP GET command, capture the HTTP response code, and clean up.
+		curl_easy_perform( curl );
+		curl_easy_getinfo( curl, CURLINFO_RESPONSE_CODE, &httpCode );
+		curl_easy_cleanup( curl );
+
+		if( httpCode != 200 ) {
+			std::cerr << "Couldn't GET from " << url << '\n';
+			return boost::none;
+		}
+
+		return httpData;
+	}
+
+	bool is_url( boost::string_view path ) {
+		return boost::starts_with( path.data( ), "http://" ) || boost::starts_with( path.data( ), "https://" );
+	}
+}	// namespace anonymous
 
 int main( int argc, char ** argv ) {
 	using namespace daw::json_to_cpp;
-
-	std::ifstream in_file;
-	in_file.open( argv[1] );
-	if( !in_file ) {
-		std::cerr << "Must supply valid json file on commandline\n";
+	if( argc != 2 ) {
+		std::cerr << "Must supply a url or a file as the json source\n";
 		exit( EXIT_FAILURE );
 	}
-	std::string json_blob;
-	std::copy( std::istream_iterator<char>{ in_file }, std::istream_iterator<char>{ }, std::back_inserter( json_blob ) );
-	in_file.close( );
+	std::string const uri{ argv[1] };
+	std::string json_str;
+	if( is_url( uri ) ) {
+		auto tmp = download( uri );
+		if( tmp ) {
+			json_str = *tmp;
+		} else {
+			std::cerr << "Could not download json data from '" << uri << "'\n";
+			exit( EXIT_FAILURE );
+		}
+	} else {
+		std::ifstream in_file;
+		in_file.open( argv[1] );
+		if( !in_file ) {
+			std::cerr << "Must supply valid json file on commandline\n";
+			exit( EXIT_FAILURE );
+		}
+		std::copy( std::istream_iterator<char>{ in_file }, std::istream_iterator<char>{ }, std::back_inserter( json_str ) );
+		in_file.close( );
+	}
 	config_t config{ };
-	generate_cpp( json_blob, std::cout, config );
+	generate_cpp( json_str, std::cout, config );
 	std::cout << std::endl;
 
 	return EXIT_SUCCESS;