Grails, Groovy - tokenize() splitting a comma and whitespace together

I have a Grails project that gets list of input from a form. I used an autocomplete jQuery UI and lists courses like English, Math, Science, Social Studies,. When I use the tokenize(', ') method, it splits Social Studies. The list becomes [English, Math, Science, Social, Studies] If I use tokenize(',') it does not split Social Studies but puts null at the end like [English, Math, Science, Social Studies, null]

def save(Student studentInstance) { .... def courseInputList = params.course.tokenize(', ') for (item in courseInputList){ def courseID = Course.findByCourseLike(item) StudnetCourse.link(studentInstance,courseID) } .... } 

How can I have the tokenize() delimeter be exactly ,(one whitespace), but either , or (one whitespace). I hope what I'm trying to explain makes sense.

Thank you in advance.

(I have it, for now, that javascript doesn't put a whitespace after a comma. It works fine with one delimeter. )

2 Answers

Use split instead

params.course = params.course?.split(', ')?: [] params.course.each{ item -> def courseID = Course.findByCourseLike(item) StudnetCourse.link(studentInstance,courseID) } 

Since you have no control over the String input, which gets a trailing comma at the end, I suggest you do some processing of the input first before tokenization or splitting.

Assuming your input string is input,

def input = params.course 

you can either use slicing,

def processedString = input.endsWith(',') ? input[0..input.size() - 1] : input 

or string subtraction using regular expression,

def processedString = input - ~/,\s*$/ 

which will remove the trailing comma. The only difference is that, with the string subtraction, the regex also checks for any trailing white spaces after the comma so it's a lot more flexible.

With the trailing comma gone, you can do tokenization or splitting. I suggest you use ',' to do so and just trim in the resulting list of outputs to remove the spaces.

def courses = processedString.split(',').collect { it.trim() } 

So the resulting code would be:

def processedString = params.course - ~/,\s*$/ def courses = processedString.split(',').collect { it.trim() } courses.each { course -> //do what you want to do with course }