multiselect gets index before splitting, causing issues with numerical lists or any unique values that contain substrings of other unique values

[rook218]

https://github.com/fateh999/react-native-paper-dropdown/blob/master/src/DropDown.tsx#L127-L128

In these lines, if you have a list like this:

ant,dog,antelope,anteater,penguin

Then you can't appropriately select / deselect ant.

That's because the code checks for an instance of ant in the entire substring, not in a split array of values.

Similarly, if your values are 1,3,7,10,0,30 then you can't select/ deselect 1, 0, or 3 because after you remove 1 from your list of values, '3,7,10,0,30'.indexOf(1) will return > -1 so the dropdown logic still thinks that '1' is in the list of selected values.

So it's necessary to split the string into an array before checking for the index.

[rook218]

This can be resolved by changing these method signatures to the following https://github.com/fateh999/react-native-paper-dropdown/blob/master/src/DropDown.tsx#L113-L141

    const isActive = useCallback(
      (currentValue: any) => {
        if (multiSelect) {
          return value.split(',').indexOf(currentValue) !== -1;
        } else {
          return value === currentValue;
        }
      },
      [value]
    );

    const setActive = useCallback(
      (currentValue: any) => {
        if (multiSelect) {
          const values = value.split(",");
          const valueIndex = values.indexOf(currentValue);
          if (valueIndex === -1) {
            setValue([...values, currentValue].join(","));
          } else {
            setValue(
              [...values].filter((value) => value !== currentValue).join(",")
            );
          }
        } else {
          setValue(currentValue);
        }
      },
      [value]
    );

Diff can be seen here: https://diffcheck.io/y-hricPbTaWnxwB9q4

[rook218]

@fateh999 I'm not able to create a branch so that I can start the PR process to fix this breaking bug - what is the appropriate way to go about it?

[rook218]

Just found that it also needs a split on this line: https://github.com/fateh999/react-native-paper-dropdown/blob/master/src/DropDown.tsx#L101

.filter((_) => value.split(',').indexOf(_.value) !== -1)

[fateh999]

Should be fixed in latest release v2.0.2, did a full refactor of library so docs are in WIP, meanwhile you can check the example folder for demo code.