How can I concatenate NSAttributedStrings? - ios

Question

I need to search some strings and set some attributes prior to merging the strings, so having NSStrings -> Concatenate them -> Make NSAttributedString is not an option, is there any way to concatenate attributedString to another attributedString?

Answer 1

I'd recommend you use a single mutable attributed string a #Linuxios suggested, and here's another example of that:
NSMutableAttributedString *mutableAttString = [[NSMutableAttributedString alloc] init];
NSString *plainString = // ...
NSDictionary *attributes = // ... a dictionary with your attributes.
NSAttributedString *newAttString = [[NSAttributedString alloc] initWithString:plainString attributes:attributes];
[mutableAttString appendAttributedString:newAttString];
However, just for the sake of getting all the options out there, you could also create a single mutable attributed string, made from a formatted NSString containing the input strings already put together. You could then use addAttributes: range: to add the attributes after the fact to the ranges containing the input strings. I recommend the former way though.

Answer 2

If you're using Swift, you can just overload the + operator so that you can concatenate them in the same way you concatenate normal strings:
// concatenate attributed strings
func + (left: NSAttributedString, right: NSAttributedString) -> NSAttributedString
{
let result = NSMutableAttributedString()
result.append(left)
result.append(right)
return result
}
Now you can concatenate them just by adding them:
let helloworld = NSAttributedString(string: "Hello ") + NSAttributedString(string: "World")

Answer 3

Swift 3: Simply create a NSMutableAttributedString and append the attributed strings to them.
let mutableAttributedString = NSMutableAttributedString()
let boldAttribute = [
NSFontAttributeName: UIFont(name: "GothamPro-Medium", size: 13)!,
NSForegroundColorAttributeName: Constants.defaultBlackColor
]
let regularAttribute = [
NSFontAttributeName: UIFont(name: "Gotham Pro", size: 13)!,
NSForegroundColorAttributeName: Constants.defaultBlackColor
]
let boldAttributedString = NSAttributedString(string: "Warning: ", attributes: boldAttribute)
let regularAttributedString = NSAttributedString(string: "All tasks within this project will be deleted. If you're sure you want to delete all tasks and this project, type DELETE to confirm.", attributes: regularAttribute)
mutableAttributedString.append(boldAttributedString)
mutableAttributedString.append(regularAttributedString)
descriptionTextView.attributedText = mutableAttributedString
swift5 upd:
let captionAttribute = [
NSAttributedString.Key.font: Font.captionsRegular,
NSAttributedString.Key.foregroundColor: UIColor.appGray
]

Answer 4

Try this:
NSMutableAttributedString* result = [astring1 mutableCopy];
[result appendAttributedString:astring2];
Where astring1 and astring2 are NSAttributedStrings.

Answer 5

2020 | SWIFT 5.1:
You're able to add 2 NSMutableAttributedString by the following way:
let concatenated = NSAttrStr1.append(NSAttrStr2)
Another way works with NSMutableAttributedString and NSAttributedString both:
[NSAttrStr1, NSAttrStr2].joinWith(separator: "")
Another way is....
var full = NSAttrStr1 + NSAttrStr2 + NSAttrStr3
and:
var full = NSMutableAttributedString(string: "hello ")
// NSAttrStr1 == 1
full += NSAttrStr1 // "hello 1"
full += " world" // "hello 1 world"
You can do this with the following extension:
// works with NSAttributedString and NSMutableAttributedString!
public extension NSAttributedString {
static func + (left: NSAttributedString, right: NSAttributedString) -> NSAttributedString {
let leftCopy = NSMutableAttributedString(attributedString: left)
leftCopy.append(right)
return leftCopy
}
static func + (left: NSAttributedString, right: String) -> NSAttributedString {
let leftCopy = NSMutableAttributedString(attributedString: left)
let rightAttr = NSMutableAttributedString(string: right)
leftCopy.append(rightAttr)
return leftCopy
}
static func + (left: String, right: NSAttributedString) -> NSAttributedString {
let leftAttr = NSMutableAttributedString(string: left)
leftAttr.append(right)
return leftAttr
}
}
public extension NSMutableAttributedString {
static func += (left: NSMutableAttributedString, right: String) -> NSMutableAttributedString {
let rightAttr = NSMutableAttributedString(string: right)
left.append(rightAttr)
return left
}
static func += (left: NSMutableAttributedString, right: NSAttributedString) -> NSMutableAttributedString {
left.append(right)
return left
}
}

Answer 6

If you're using Cocoapods, an alternative to both above answers that let you avoid mutability in your own code is to use the excellent NSAttributedString+CCLFormat category on NSAttributedStrings that lets you write something like:
NSAttributedString *first = ...;
NSAttributedString *second = ...;
NSAttributedString *combined = [NSAttributedString attributedStringWithFormat:#"%#%#", first, second];
It of course it just uses NSMutableAttributedString under the covers.
It also has the extra advantage of being a fully fledged formatting function — so it can do a lot more than appending strings together.

Answer 7

// Immutable approach
// class method
+ (NSAttributedString *)stringByAppendingString:(NSAttributedString *)append toString:(NSAttributedString *)string {
NSMutableAttributedString *result = [string mutableCopy];
[result appendAttributedString:append];
NSAttributedString *copy = [result copy];
return copy;
}
//Instance method
- (NSAttributedString *)stringByAppendingString:(NSAttributedString *)append {
NSMutableAttributedString *result = [self mutableCopy];
[result appendAttributedString:append];
NSAttributedString *copy = [result copy];
return copy;
}

Answer 8

You can try SwiftyFormat
It uses following syntax
let format = "#{{user}} mentioned you in a comment. #{{comment}}"
let message = NSAttributedString(format: format,
attributes: commonAttributes,
mapping: ["user": attributedName, "comment": attributedComment])

Answer 9

private var fillAttributes:[NSMutableAttributedString.Key : Any]? = nil
fontAttributes = [.foregroundColor : SKColor.red,
.strokeWidth : 0.0,
.font : CPFont(name: "Verdana-Bold",
.size : 50,]
fontAttributes.updateValue(SKColor.green, forKey: .foregroundColor)