The code reads in (large) HTML files as String, performs some adaptations to the String, converts it to a NSAttributedString/NSMutableAttributedString and performs some concatenation/mutation operations on them again and finally displays the results in a UITextViews.
Problem
This works fine for most of the HTML files. But (recently) for some large(r) files it crashes with the following error:
Thread 1: "*** -[NSBigMutableString getCharacters:range:]: Range {7825, 1} out of bounds; string length 7811"
Relevant parts of the code:
let htmlText = try? String(contentsOfFile: filePath, encoding: String.Encoding.utf8)
...
htmlText.html(fontSize: fontSizeBody, textAlign: .natural, mainTextColor: Theme.Color.darkLight)
...
[Some NSMutableAttributedString concatenations/operations]
...
let attributedText = NSAttributedString(attributedString: mutableAttributedText)
print(attributedText) // => No problem here (the expected output is shown)
self.textView.attributedText = attributedText // => Crash, but just for large(r) files
If I delete some lines of the large(r) HTML file the code works as intended.
The question is: How to solve this issue?
More log output:
*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSBigMutableString getCharacters:range:]: Range {7825, 1} out of bounds; string length 7811'
*** First throw call stack:
(
0 CoreFoundation 0x000000010bd37604 __exceptionPreprocess + 242
1 libobjc.A.dylib 0x0000000109a84a45 objc_exception_throw + 48
2 Foundation 0x000000010a5acb8a -[NSBigMutableString replaceCharactersInRange:withString:] + 0
3 UIFoundation 0x0000000119d7e3e4 _NSFastFillAllLayoutHolesForGlyphRange + 923
4 UIFoundation 0x0000000119dd652a -[NSLayoutManager enumerateLineFragmentsForGlyphRange:usingBlock:] + 72
5 UIKitCore 0x000000011ce8d8a6 __38-[UITextView _rectForScrollToVisible:]_block_invoke + 141
6 UIFoundation 0x0000000119dd6c08 -[NSLayoutManager(TextLocking) coordinateAccess:] + 47
7 UIKitCore 0x000000011ce8d5dc -[UITextView _rectForScrollToVisible:] + 294
8 UIKitCore 0x000000011ce88a5c -[UITextView _updateFrameOfTrailingWhitespace:] + 115
9 UIKitCore 0x000000011ce88cb2 -[UITextView _updateContentSize] + 451
10 UIKitCore 0x000000011ce889d6 -[UITextView _textContainerSizeDidChange:] + 27
11 CoreFoundation 0x000000010bc7609d __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
12 CoreFoundation 0x000000010bc76063 ___CFXRegistrationPost_block_invoke + 49
13 CoreFoundation 0x000000010bc755b0 _CFXRegistrationPost + 496
14 CoreFoundation 0x000000010bc74ee6 _CFXNotificationPost + 822
15 Foundation 0x000000010a66df4c -[NSNotificationCenter postNotificationName:object:userInfo:] + 82
16 UIKitCore 0x000000011ce999b4 __76-[_UITextContainerView _setFrameOrBounds:oldRect:isFrameRect:settingAction:]_block_invoke.71 + 366
17 UIKitCore 0x000000011ce997c0 -[_UITextContainerView _setFrameOrBounds:oldRect:isFrameRect:settingAction:] + 733
18 UIKitCore 0x000000011ce99c2a -[_UITextContainerView setFrame:] + 161
19 UIKitCore 0x000000011ce99e62 -[_UITextContainerView setConstrainedFrameSize:] + 488
20 UIFoundation 0x0000000119d7b459 -[NSLayoutManager(NSPrivate) _resizeTextViewForTextContainer:] + 1084
21 UIFoundation 0x0000000119d7aede -[NSLayoutManager(NSPrivate) _recalculateUsageForTextContainerAtIndex:] + 1908
22 UIFoundation 0x0000000119d7af4f -[NSLayoutManager(NSPrivate) _validatedStoredUsageForTextContainerAtIndex:] + 82
23 UIFoundation 0x0000000119dd1f70 -[NSLayoutManager usedRectForTextContainer:] + 118
24 UIKitCore 0x000000011ce991f9 -[_UITextContainerView textContainerOrigin] + 158
25 UIFoundation 0x0000000119e031e6 -[NSTextContainer textContainerOrigin] + 161
26 UIKitCore 0x000000011ce70743 -[UITextInputController caretRectForPosition:] + 610
27 UIKitCore 0x000000011ce90629 -[UITextView caretRectForPosition:] + 73
28 UIKitCore 0x000000011ce0bafb -[UITextSelection caretRect] + 162
29 UIKitCore 0x000000011ce8867d -[UITextView _scrollToCaretIfNeeded] + 352
30 UIKitCore 0x000000011ce91453 -[UITextView textInputDidChangeSelection:] + 90
31 UIKitCore 0x000000011ce66513 -[UITextInputController _sendDelegateChangeNotificationsForText:selection:] + 80
32 UIKitCore 0x000000011ce67e56 __46-[UITextInputController setSelectedTextRange:]_block_invoke.538 + 292
33 UIKitCore 0x000000011ce68227 __52-[UITextInputController _coordinateSelectionChange:]_block_invoke + 108
34 UIFoundation 0x0000000119e07541 -[NSTextStorage coordinateReading:] + 42
35 UIKitCore 0x000000011ce68191 -[UITextInputController _coordinateSelectionChange:] + 150
36 UIKitCore 0x000000011ce67b5e -[UITextInputController setSelectedTextRange:] + 535
37 UIKitCore 0x000000011ce67fe6 -[UITextInputController setSelectedRange:] + 92
38 UIKitCore 0x000000011ce91fa0 -[UITextView setSelectedRange:] + 67
39 UIKitCore 0x000000011ce87613 -[UITextView setAttributedText:] + 1006
...
)
UPDATE
I found out that the part in the HTML file that causes the crash is a table tag with very long String in one of its td tags:
<table>
<tr>
<td>
adsfsdfadsf:
</td>
<td>
hkavdhsghasgdvfhjgasvdfhgasdvhjfgvashjgdfvjhagsvdfhjavsdhjfvajhsdgfhjagsvfjhagsvjdhfvajhsdgfvjhasgvdfjhgahkavdhsghasgdvfhjgasvdfhgasdvhjfgvashjgdfvjhagsvdfhjavsdhjfvajhsdgfhjagsvfjhagsvjdhfvajhsdgfvjhasgvdfjhga
</td>
</tr>
</table>
I found out that the part in the HTML file that causes the crash is a table tag with very long String in one of its td tags:
<table>
<tr>
<td>
adsfsdfadsf:
</td>
<td>
hkavdhsghasgdvfhjgasvdfhgasdvhjfgvashjgdfvjhagsvdfhjavsdhjfvajhsdgfhjagsvfjhagsvjdhfvajhsdgfvjhasgvdfjhgahkavdhsghasgdvfhjgasvdfhgasdvhjfgvashjgdfvjhagsvdfhjavsdhjfvajhsdgfhjagsvfjhagsvjdhfvajhsdgfvjhasgvdfjhga
</td>
</tr>
</table>
The issue seems to appear whenever the text long text can't be displayed in one line. While this worked fine in the past, the problem occurs in newer iOS versions.
To avoid this error: