Fix TextInput stack overflow when pasting text in multiline input wit…

…h maxlength

Summary: When pasting text longer than maxlenght, the textDidChange: call we did would end calling back into textView:shouldChange: because we saw an unexpected multi-character change. Since this is an expected mutation, update predictedText appropriately.

Reviewed By: majak

Differential Revision: D3561524

fbshipit-source-id: 07bb78d830ccfa3aed6ee274dc30adeadce9e1f8

Examples/UIExplorer/js/TextInputExample.ios.js

@@ -679,6 +679,12 @@ exports.examples = [
             keyboardType="url"
             style={[styles.multiline, styles.multilineWithFontStyles]}
           />
+          <TextInput
+            placeholder="multiline text input with max length"
+            maxLength={5}
+            multiline={true}
+            style={styles.multiline}
+          />
           <TextInput
             placeholder="uneditable multiline text input"
             editable={false}

Libraries/Text/RCTTextView.m

@@ -377,16 +377,20 @@ - (BOOL)textView:(RCTUITextView *)textView shouldChangeTextInRange:(NSRange)rang
   if (_maxLength) {
     NSUInteger allowedLength = _maxLength.integerValue - textView.text.length + range.length;
     if (text.length > allowedLength) {
+      // If we typed/pasted more than one character, limit the text inputted
       if (text.length > 1) {
         // Truncate the input string so the result is exactly maxLength
         NSString *limitedString = [text substringToIndex:allowedLength];
         NSMutableString *newString = textView.text.mutableCopy;
         [newString replaceCharactersInRange:range withString:limitedString];
         textView.text = newString;
+        _predictedText = newString;
+
         // Collapse selection at end of insert to match normal paste behavior
         UITextPosition *insertEnd = [textView positionFromPosition:textView.beginningOfDocument
                                                             offset:(range.location + allowedLength)];
         textView.selectedTextRange = [textView textRangeFromPosition:insertEnd toPosition:insertEnd];
+
         [self textViewDidChange:textView];
       }
       return NO;