Interfacing between JavaScript and Objective-C on iOS devices

Question

Interfacing between JavaScript and Objective-C on iOS devices

One method of communication between iOS and JavaScript involves creating fake URLs in JavaScript and appending a string as a parameter to Objective-C code. This URL is then parsed in the delegate method:

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType

The return value from this process is sent by invoking the native method

stringByEvaluatingJavaScriptFromString

with the parameter callID.

However, I am interested in finding a way to directly call Objective-C methods from JavaScript on iOS, similar to how it can be done on Android without requiring additional JavaScript code to retrieve the return value. Our existing JavaScript code functions seamlessly with Android, but we are seeking a solution that will also meet AppStore requirements for iOS.

javascript android ios objective-c uiwebview

Answer 1

Answer №1

If you're looking to accomplish this task, there isn't a native method available. However, utilizing a tool like WebViewJavascriptBridge can help facilitate the process: https://github.com/marcuswestin/WebViewJavascriptBridge.

Even if there was an integrated solution in place, the lack of established standards would complicate things. In any case, achieving consistency with Android functionality is unlikely. Transitioning to Obj-C code involves transitioning away from web technology and onto platform-specific implementations that inherently differ across platforms.

Answer 2

If you're looking to accomplish this task, there isn't a native method available. However, utilizing a tool like WebViewJavascriptBridge can help facilitate the process: https://github.com/marcuswestin/WebViewJavascriptBridge.

Even if there was an integrated solution in place, the lack of established standards would complicate things. In any case, achieving consistency with Android functionality is unlikely. Transitioning to Obj-C code involves transitioning away from web technology and onto platform-specific implementations that inherently differ across platforms.

Answer 3

Answer №2

To easily integrate JavaScript methods from objective C, follow these straightforward steps.

For a detailed guide, check out this resource and refer to the Apple Documentation

Answer 4

To easily integrate JavaScript methods from objective C, follow these straightforward steps.

For a detailed guide, check out this resource and refer to the Apple Documentation

Answer 5

Answer №3

After thoroughly understanding your query regarding invoking an Objective-C method from Java script, I have found a comprehensive example in the official Apple Documentation:

Let's delve into a hypothetical scenario where we create an Objective-C address book class and make it accessible to JavaScript. Here is how the class definition may look like:

@interface MyAddressBook: NSObject {
}
+ (MyAddressBook *)addressBook;
- (NSString *)nameAtIndex:(int)index;
@end

Now, let's proceed with the code snippet to expose a MyAddressBook instance to JavaScript:

MyAddressBook *myContacts = [MyAddressBook addressBook];

id windowObject = [webView windowScriptObject];
[windowObject setValue:myContacts forKey:@"ContactList"];

Once you integrate these methods into JavaScript as detailed at the conclusion of this section, you will be able to interact with your address book through standard JavaScript functions.

For demonstration purposes, let's showcase how you can utilize the MyAddressBook instance in JavaScript. For instance, here's how you could display the name of a person at a specified index in your address book:

function displayPersonName(index) {
    var contactsBook = window.ContactList;
    var name = contactsBook.nameAtIndex_(index);
    document.write(name);
}

Answer 6

After thoroughly understanding your query regarding invoking an Objective-C method from Java script, I have found a comprehensive example in the official Apple Documentation:

Let's delve into a hypothetical scenario where we create an Objective-C address book class and make it accessible to JavaScript. Here is how the class definition may look like:

@interface MyAddressBook: NSObject {
}
+ (MyAddressBook *)addressBook;
- (NSString *)nameAtIndex:(int)index;
@end

Now, let's proceed with the code snippet to expose a MyAddressBook instance to JavaScript:

MyAddressBook *myContacts = [MyAddressBook addressBook];

id windowObject = [webView windowScriptObject];
[windowObject setValue:myContacts forKey:@"ContactList"];

Once you integrate these methods into JavaScript as detailed at the conclusion of this section, you will be able to interact with your address book through standard JavaScript functions.

For demonstration purposes, let's showcase how you can utilize the MyAddressBook instance in JavaScript. For instance, here's how you could display the name of a person at a specified index in your address book:

function displayPersonName(index) {
    var contactsBook = window.ContactList;
    var name = contactsBook.nameAtIndex_(index);
    document.write(name);
}

Interfacing between JavaScript and Objective-C on iOS devices

Answer №1

Answer №2

Answer №3

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