Use of undeclared type in Swift project

Question

I am trying to import this library in my Swift project. I am doing all step by step from this document and this answer, but nothing works.

Here is my screenshot:

Here is my Bridging-Header.h:

//
//  Use this file to import your target's public headers that you would like to expose to Swift.
//

#import <UIKit/UIKit.h>

#import "VKUser.h"
#import "VKAccessToken.h"
#import "VKCache.h"
#import "VKStorage.h"
#import "VKStorageItem.h"
#import "VKRequestManager.h"
#import "VKRequest.h"
#import "VKConnector.h"
#import "VKMethods.h"

#import "NSData+toBase64.h"
#import "NSString+Utilities.h"

The important thing is that I have VKConnector class and VKConnectorDelegate protocol in one file. Maybe thats the problem?

//
// Copyright (c) 2013 Andrew Shmig
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import "VKMethods.h"
#import "VKAccessToken.h"
#import "VKStorage.h"
#import "NSString+Utilities.h"
#import "VKStorageItem.h"


@class VKConnector;


static NSString *const kVKErrorDomain = @"kVkontakteErrorDomain";


typedef enum
{
    kVKApplicationWasDeletedErrorCode
} kVkontakteErrorCode;


/** Protocol incapsulates methods that are triggered during user authorization
 process or access token status changes.
 */
@protocol VKConnectorDelegate <NSObject>

@optional
/**
 @name Show/hide web view
 */
/** Method is called when user needs to perform some action (enter login and
password, authorize your application etc)

@param connector VKConnector instance that sends notifications
@param webView UIWebView that displays authorization page
*/
- (void)VKConnector:(VKConnector *)connector
    willShowWebView:(UIWebView *)webView;

/** Method is called when UIWebView should be hidden, this method is called after
user has entered login+password or has authorized an application (or pressed
cancel button etc).

@param connector VKConnector instance that sends notifications
@param webView UIWebView that displays authorization page and needs to be hidden
*/
- (void)VKConnector:(VKConnector *)connector
    willHideWebView:(UIWebView *)webView;

/**
@name UIWebView started/finished loading a frame
*/
/** Method is called when UIWebView starts loading a frame

@param connector VKConnector instance that sends notifications
@param webView UIWebView that displays authorization page
*/
- (void)VKConnector:(VKConnector *)connector
webViewDidStartLoad:(UIWebView *)webView;

/** Method is called when UIWebView finishes loading a frame

@param connector VKConnector instance that sends notifications
@param webView UIWebView that displays authorization page
*/
- (void) VKConnector:(VKConnector *)connector
webViewDidFinishLoad:(UIWebView *)webView;

/**
 @name Access token
 */
/** Method is called when access token is successfully updated

@param connector VKConnector instance that sends notifications
@param accessToken updated access token
*/
- (void)        VKConnector:(VKConnector *)connector
accessTokenRenewalSucceeded:(VKAccessToken *)accessToken;

/** Method is called when access token failed to be updated. The main reason
could be that user denied/canceled to authorize your application.

@param connector VKConnector instance that sends notifications
@param accessToken access token (equals to nil)
*/
- (void)     VKConnector:(VKConnector *)connector
accessTokenRenewalFailed:(VKAccessToken *)accessToken;

/**
 @name Connection & Parsing
 */
/** Method is called when connection error occurred during authorization process.

@param connector VKConnector instance that sends notifications
@param error error description
*/
- (void)VKConnector:(VKConnector *)connector
    connectionError:(NSError *)error;

/** Method is called if VK application was deleted.

@param connector VKConnector instance that sends notifications
@param error error description
*/
- (void)  VKConnector:(VKConnector *)connector
applicationWasDeleted:(NSError *)error;

@end


/** The main purpose of this class is to process user authorization and obtain
access token which then will be used to perform requests from behalf of current
user.

Example:

    [[VKConnector sharedInstance] startWithAppID:@"12345567"
                                  permissions:@[@"wall"]
                                  webView:webView
                                  delegate:self];
*/
@interface VKConnector : NSObject <UIWebViewDelegate>

/**
@name Properties
*/
/** Delegate
 */
@property (nonatomic, weak, readonly) id <VKConnectorDelegate> delegate;

/** Application's unique identifier
*/
@property (nonatomic, strong, readonly) NSString *appID;

/** Permissions
*/
@property (nonatomic, strong, readonly) NSArray *permissions;

/**
@name Class methods
*/
/** Returns shared instances of VKConnector class.
*/
+ (id)sharedInstance;

/**
@name User authorization
*/
/** Starts user authorization process.

@param appID application's unique identifier
@param permissions array of permissions (wall, friends, audio, video etc)
@param webView UIWebView which will be used to display VK authorization page
@param delegate delegate which will receive notifications
*/
- (void)startWithAppID:(NSString *)appID
            permissons:(NSArray *)permissions
               webView:(UIWebView *)webView
              delegate:(id <VKConnectorDelegate>)delegate;

/**
@name Cookies
*/
/** Removes all cookies which were obtained after user has authorized VK
application. This method is used to log out current user.
*/
- (void)clearCookies;

@end

I have tried to split VKConnector header file into two - VKConnector class and VKConnectorDelegate, but that didn't work.

What am I doing wrong?

Answer 1

Your delegate function name is VKConnector and you also have a class named VKConnector. That's your conflict. In Objective C your delegate method is VKConnector:withBool: but in Swift it's simply VKConnector and withBool is not a part of the name.

If you follow Cocoa patterns, your delegate method should be called - (void) connector:(VKConnector *)connector withBool:(BOOL)boolean;

Answer 2

Did XCode create your bridging header file or did you create the file by yourself?

If you created the bridging header file yourself, make sure that build settings point to your file:

Answer 3

The "undeclared type" error in a mixed project is nearly always solved as I have explained here:

https://stackoverflow.com/a/24216718/341994

Basically, wherever you are importing the automatically generated "...-Swift.h" header file into your Objective-C code, you will need to import "VKConnector.h" into that file as well, earlier in the list of imports.

This is counterintuitive and annoying, but it solves the problem, and in fact is actually documented if you look very closely.