THRIFT-1897 cocoa: Support validation of required fields
Patch: Kevin Li
diff --git a/compiler/cpp/src/generate/t_cocoa_generator.cc b/compiler/cpp/src/generate/t_cocoa_generator.cc
index c4265f7..15311cc 100644
--- a/compiler/cpp/src/generate/t_cocoa_generator.cc
+++ b/compiler/cpp/src/generate/t_cocoa_generator.cc
@@ -56,6 +56,9 @@
     iter = parsed_options.find("log_unexpected");
     log_unexpected_ = (iter != parsed_options.end());    
     
+    iter = parsed_options.find("validate_required");
+    validate_required_ = (iter != parsed_options.end());    
+    
     out_dir_base_ = "gen-cocoa";
   }
 
@@ -101,6 +104,7 @@
   void generate_cocoa_struct_reader(std::ofstream& out, t_struct* tstruct);
   void generate_cocoa_struct_result_writer(std::ofstream& out, t_struct* tstruct);
   void generate_cocoa_struct_writer(std::ofstream& out, t_struct* tstruct);
+  void generate_cocoa_struct_validator(std::ofstream& out, t_struct* tstruct);
   void generate_cocoa_struct_description(std::ofstream& out, t_struct* tstruct);
 
   std::string function_result_helper_struct_type(t_function* tfunction);
@@ -217,6 +221,7 @@
   std::ofstream f_impl_;
 
   bool log_unexpected_;
+  bool validate_required_;
 };
 
 
@@ -279,6 +284,7 @@
   string result = string() +
     "#import \"TProtocol.h\"\n" +
     "#import \"TApplicationException.h\"\n" +
+    "#import \"TProtocolException.h\"\n" +
     "#import \"TProtocolUtil.h\"\n" +
     "#import \"TProcessor.h\"\n" +
     "#import \"TObjective-C.h\"\n" +
@@ -514,6 +520,9 @@
   out << "- (void) write: (id <TProtocol>) outProtocol;" << endl;
   out << endl;
 
+  // validator
+  out << "- (void) validate;" << endl << endl;
+
   // getters and setters
   generate_cocoa_struct_field_accessor_declarations(out, tstruct, is_exception);
 
@@ -807,6 +816,7 @@
   } else {
     generate_cocoa_struct_writer(out, tstruct);
   }
+  generate_cocoa_struct_validator(out, tstruct);
   generate_cocoa_struct_description(out, tstruct);
 
   out << "@end" << endl << endl;
@@ -910,6 +920,12 @@
     out <<
       indent() << "[inProtocol readStructEnd];" << endl;
 
+    // performs various checks (e.g. check that all required fields are set)
+    if (validate_required_) {
+      out <<
+        indent() << "[self validate];" << endl;
+    }
+
   indent_down();
   out <<
     indent() << "}" << endl <<
@@ -1047,6 +1063,39 @@
 }
 
 /**
+ * Generates a function to perform various checks
+ * (e.g. check that all required fields are set)
+ *
+ * @param tstruct The struct definition
+ */
+void t_cocoa_generator::generate_cocoa_struct_validator(ofstream& out,
+                                                        t_struct* tstruct) {
+  out <<
+    indent() << "- (void) validate {" << endl;
+  indent_up();
+
+  const vector<t_field*>& fields = tstruct->get_members();
+  vector<t_field*>::const_iterator f_iter;
+    
+  out << indent() << "// check for required fields" << endl;
+  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
+    t_field* field = (*f_iter);
+    if ((*f_iter)->get_req() == t_field::T_REQUIRED) {
+      out <<
+        indent() << "if (!__" << field->get_name() << "_isset) {" << endl <<
+        indent() << "  @throw [TProtocolException exceptionWithName: @\"TProtocolException\"" << endl <<
+        indent() << "                             reason: @\"Required field '" << (*f_iter)->get_name() << "' is not set.\"];" << endl <<
+        indent() << "}" << endl;
+    }
+  }
+
+  indent_down();
+  out <<
+    indent() << "}" << endl <<
+    endl;
+}
+
+/**
  * Generate property accessor methods for all fields in the struct.
  * getter, setter, isset getter.
  *
@@ -2671,5 +2720,7 @@
 
 THRIFT_REGISTER_GENERATOR(cocoa, "Cocoa",
 "    log_unexpected:  Log every time an unexpected field ID or type is encountered.\n"
+"    validate_required:\n"
+"                     Throws exception if any required field is not set.\n"
 )