Copy NSAttributedString in UIPasteBoard

How do you copy an NSAttributedString in the pasteboard, to allow the user to paste, or to paste programmatically (with - (void)paste:(id)sender, from UIResponderStandardEditActions protocol).

I tried:

UIPasteboard *pasteBoard = [UIPasteboard generalPasteboard];
[pasteBoard setValue:attributedString forPasteboardType:(NSString *)kUTTypeRTF];

but this crash with:

-[UIPasteboard setValue:forPasteboardType:]: value is not a valid property list type'

which is to be expected, because NSAttributedString is not a property list value.

If the user paste the content of the pasteboard in my app, I would like to keep all the standards and custom attributes of the attributed string.

Solution 1:

I have found that when I (as a user of the application) copy rich text from a UITextView into the pasteboard, the pasteboard contains two types:

"public.text",
"Apple Web Archive pasteboard type

Based on that, I created a convenient category on UIPasteboard.
(With heavy use of code from this answer).

It works, but:
The conversion to html format means I will lose custom attributes. Any clean solution will be gladly accepted.

File UIPasteboard+AttributedString.h:

@interface UIPasteboard (AttributedString)

- (void) setAttributedString:(NSAttributedString *)attributedString;

@end

File UIPasteboard+AttributedString.m:

#import <MobileCoreServices/UTCoreTypes.h>

#import "UIPasteboard+AttributedString.h"

@implementation UIPasteboard (AttributedString)

- (void) setAttributedString:(NSAttributedString *)attributedString {
    NSString *htmlString = [attributedString htmlString]; // This uses DTCoreText category NSAttributedString+HTML - https://github.com/Cocoanetics/DTCoreText
    NSDictionary *resourceDictionary = @{ @"WebResourceData" : [htmlString dataUsingEncoding:NSUTF8StringEncoding],
    @"WebResourceFrameName":  @"",
    @"WebResourceMIMEType" : @"text/html",
    @"WebResourceTextEncodingName" : @"UTF-8",
    @"WebResourceURL" : @"about:blank" };



    NSDictionary *htmlItem = @{ (NSString *)kUTTypeText : [attributedString string],
        @"Apple Web Archive pasteboard type" : @{ @"WebMainResource" : resourceDictionary } };

    [self setItems:@[ htmlItem ]];
}


@end

Only implemented setter. If you want to write the getter, and/or put it on GitHub, be my guest :)

Solution 2:

Instead of involving HTML, the clean solution is to insert NSAttributedString as RTF (plus plaintext fallback) into the paste board:

- (void)setAttributedString:(NSAttributedString *)attributedString {
    NSData *rtf = [attributedString dataFromRange:NSMakeRange(0, attributedString.length)
                               documentAttributes:@{NSDocumentTypeDocumentAttribute: NSRTFTextDocumentType}
                                            error:nil];
    self.items = @[@{(id)kUTTypeRTF: [[NSString alloc] initWithData:rtf encoding:NSUTF8StringEncoding],
                     (id)kUTTypeUTF8PlainText: attributedString.string}];
}

Swift 5

import MobileCoreServices

public extension UIPasteboard {
    func set(attributedString: NSAttributedString) {
        do {
            let rtf = try attributedString.data(from: NSMakeRange(0, attributedString.length), documentAttributes: [NSAttributedString.DocumentAttributeKey.documentType: NSAttributedString.DocumentType.rtf])
            items = [[kUTTypeRTF as String: NSString(data: rtf, encoding: String.Encoding.utf8.rawValue)!, kUTTypeUTF8PlainText as String: attributedString.string]]
        } catch {
        }
    }
}

Solution 3:

It is quite simple:

  #import <MobileCoreServices/UTCoreTypes.h>

  NSMutableDictionary *item = [[NSMutableDictionary alloc] init];

  NSData *rtf = [attributedString dataFromRange:NSMakeRange(0, attributedString.length)
                             documentAttributes:@{NSDocumentTypeDocumentAttribute: NSRTFDTextDocumentType}
                                          error:nil];

  if (rtf) {
    [item setObject:rtf forKey:(id)kUTTypeFlatRTFD];
  }

  [item setObject:attributedString.string forKey:(id)kUTTypeUTF8PlainText];

  UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
  pasteboard.items = @[item];