How can I chunk a string in JavaScript respecting words?

Question

I have a large block of text and I want to split that into an array with each element being one line of up to 50 characters. If the string contains a \r or \n, I want that to be an element itself (not part of another string). I'm a bit perplexed on how to do this.

I've tried

lines = newVal.match(/^(\r\n|.){1,50}\b/g)

I've also tried underscore / lodash _.chunk but that ignores words obviously. But this gives me only the first match. Please help.

Answer 1

Try this:

result = lines.split(/(?=(\r\n))/g);
result.forEach(function(item,index,arr) {
  if(item.length > 50) {
    var more = item.match(/.{1,50}\b/g);
    arr[index] = more[0];
    for(var i=1; i<more.length; ++i) {
      arr.splice(index+i, 0, more[i]);      
    }
  }
});

This will first split the text into an array by your newlines, then go and further break up the long lines in the array, maintaining the words.

Answer 2

Try using String.prototype.split() , while loop , Array.prototype.some() , Array.prototype.filter() , String.prototype.slice() , Array.prototype.splice()

// call `.split()` of `largeBlockOfText` with `RegExp` `/\r|\n/` 
var arr = largeBlockOfText.split(/\r|\n/);
// while `arr` has element where `.length` greater than `50`
while (arr.some(function(v) {return v.length > 50})) {
  // filter element in `arr` where element has `.length` greater than `50`
  var j = arr.filter(function(val, key) {
    return val.length > 50
  })[0]
  // get index of `j` within `arr`
  , index = arr.indexOf(j)
  // text of `j`
  , text = j
  // index to insert block of 50 characters of `text`
  , i = 1;
  while (text.length) {   
    // insert block of 50 characters from `text` at `index` + 1
    arr.splice(index + i, 0, text.slice(0, 50));
    // reset `text`
    text = text.slice(50, text.length);
    // increment `i` : `index`
    ++i;
  }
  // remove `j` , reset `i`
  arr.splice(index, 1); i = 1;
}