Add ObjC helpers for Any WKT.

- Capture the ObjC prefix used when generating the the file.
- Track the containing type on descriptors.
- Mark descriptors where the message class name got a suffix added to it.
- Expose a fullName property on Descriptors.
- Add helpers for packing/unpacking Any messages.
- Bump the ObjC runtime version number. Since we added methods and invoke them
  in the generated code, ensure the code is running against a matching version.
  Otherwise, someone could compile against headers, but run with a framework
  that is older and get unknown selector failures.  This should trip clearer
  messaging.

Fixes https://github.com/google/protobuf/issues/1674

1 files changed, 135 insertions, 0 deletions

diff --git a/objectivec/GPBWellKnownTypes.m b/objectivec/GPBWellKnownTypes.m
index 5cdd62d5..ed798a2e 100644
--- a/objectivec/GPBWellKnownTypes.m
+++ b/objectivec/GPBWellKnownTypes.m
@@ -34,6 +34,13 @@
 
 #import "GPBWellKnownTypes.h"
 
+#import "GPBUtilities_PackagePrivate.h"
+
+NSString *const GPBWellKnownTypesErrorDomain =
+    GPBNSStringifySymbol(GPBWellKnownTypesErrorDomain);
+
+static NSString *kTypePrefixGoogleApisCom = @"type.googleapis.com/";
+
 static NSTimeInterval TimeIntervalSince1970FromSecondsAndNanos(int64_t seconds,
                                                                int32_t nanos) {
   return seconds + (NSTimeInterval)nanos / 1e9;
@@ -48,6 +55,30 @@ static int32_t SecondsAndNanosFromTimeIntervalSince1970(NSTimeInterval time,
   return (int32_t)nanos;
 }
 
+static NSString *BuildTypeURL(NSString *typeURLPrefix, NSString *fullName) {
+  if (typeURLPrefix.length == 0) {
+    return fullName;
+  }
+
+  if ([typeURLPrefix hasSuffix:@"/"]) {
+    return [typeURLPrefix stringByAppendingString:fullName];
+  }
+
+  return [NSString stringWithFormat:@"%@/%@", typeURLPrefix, fullName];
+}
+
+static NSString *ParseTypeFromURL(NSString *typeURLString) {
+  NSRange range = [typeURLString rangeOfString:@"/" options:NSBackwardsSearch];
+  if ((range.location == NSNotFound) ||
+      (NSMaxRange(range) == typeURLString.length)) {
+    return nil;
+  }
+  NSString *result = [typeURLString substringFromIndex:range.location + 1];
+  return result;
+}
+
+#pragma mark - GPBTimestamp
+
 @implementation GPBTimestamp (GBPWellKnownTypes)
 
 - (instancetype)initWithDate:(NSDate *)date {
@@ -87,6 +118,8 @@ static int32_t SecondsAndNanosFromTimeIntervalSince1970(NSTimeInterval time,
 
 @end
 
+#pragma mark - GPBDuration
+
 @implementation GPBDuration (GBPWellKnownTypes)
 
 - (instancetype)initWithTimeIntervalSince1970:(NSTimeInterval)timeIntervalSince1970 {
@@ -113,3 +146,105 @@ static int32_t SecondsAndNanosFromTimeIntervalSince1970(NSTimeInterval time,
 }
 
 @end
+
+#pragma mark - GPBAny
+
+@implementation GPBAny (GBPWellKnownTypes)
+
++ (instancetype)anyWithMessage:(GPBMessage *)message
+                         error:(NSError **)errorPtr {
+  return [self anyWithMessage:message
+                typeURLPrefix:kTypePrefixGoogleApisCom
+                        error:errorPtr];
+}
+
++ (instancetype)anyWithMessage:(GPBMessage *)message
+                 typeURLPrefix:(NSString *)typeURLPrefix
+                         error:(NSError **)errorPtr {
+  return [[[self alloc] initWithMessage:message
+                          typeURLPrefix:typeURLPrefix
+                                  error:errorPtr] autorelease];
+}
+
+- (instancetype)initWithMessage:(GPBMessage *)message
+                          error:(NSError **)errorPtr {
+  return [self initWithMessage:message
+                 typeURLPrefix:kTypePrefixGoogleApisCom
+                         error:errorPtr];
+}
+
+- (instancetype)initWithMessage:(GPBMessage *)message
+                  typeURLPrefix:(NSString *)typeURLPrefix
+                          error:(NSError **)errorPtr {
+  self = [self init];
+  if (self) {
+    if (![self packWithMessage:message
+                 typeURLPrefix:typeURLPrefix
+                         error:errorPtr]) {
+      [self release];
+      self = nil;
+    }
+  }
+  return self;
+}
+
+- (BOOL)packWithMessage:(GPBMessage *)message
+                  error:(NSError **)errorPtr {
+  return [self packWithMessage:message
+                 typeURLPrefix:kTypePrefixGoogleApisCom
+                         error:errorPtr];
+}
+
+- (BOOL)packWithMessage:(GPBMessage *)message
+          typeURLPrefix:(NSString *)typeURLPrefix
+                  error:(NSError **)errorPtr {
+  NSString *fullName = [message descriptor].fullName;
+  if (fullName.length == 0) {
+    if (errorPtr) {
+      *errorPtr =
+          [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
+                              code:GPBWellKnownTypesErrorCodeFailedToComputeTypeURL
+                          userInfo:nil];
+    }
+    return NO;
+  }
+  if (errorPtr) {
+    *errorPtr = nil;
+  }
+  self.typeURL = BuildTypeURL(typeURLPrefix, fullName);
+  self.value = message.data;
+  return YES;
+}
+
+- (GPBMessage *)unpackMessageClass:(Class)messageClass
+                             error:(NSError **)errorPtr {
+  NSString *fullName = [messageClass descriptor].fullName;
+  if (fullName.length == 0) {
+    if (errorPtr) {
+      *errorPtr =
+          [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
+                              code:GPBWellKnownTypesErrorCodeFailedToComputeTypeURL
+                      userInfo:nil];
+    }
+    return nil;
+  }
+
+  NSString *expectedFullName = ParseTypeFromURL(self.typeURL);
+  if ((expectedFullName == nil) || ![expectedFullName isEqual:fullName]) {
+    if (errorPtr) {
+      *errorPtr =
+          [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
+                              code:GPBWellKnownTypesErrorCodeTypeURLMismatch
+                          userInfo:nil];
+    }
+    return nil;
+  }
+
+  // Any is proto3, which means no extensions, so this assumes anything put
+  // within an any also won't need extensions. A second helper could be added
+  // if needed.
+  return [messageClass parseFromData:self.value
+                               error:errorPtr];
+}
+
+@end