Question

Suppose I have a body of text (string) like this:

str = ‘This is some text. {insertion_1} And this is also some text. {insertion_2}’

The contents of the two curly braces represent a model (Insertion) and its ID. The ultimate goal is to parse the string, and replace the curly braced “insertions” with an insertion partial. The insertion partial will simply be a line or two of HTML.

If the insertions were static I could do something like str.gsub!(/\{insertion_\d*\}/, 'some content'), but I need to parse the insertions one-by-one, to insert the appropriate data. Can anyone suggest a best practice for handling a situation like this?

EDIT: I should have mentioned, this is for a WYSIWYG. The end user selects from a list of “insertions” and once selected, it adds the appropriate {insertion_id} placeholder into the body of their post, which will be parsed out later to insert the right content.

Answer 1

You can use regexp captures and gsub with a block to accomplish what you want, like this:

str = 'This is some text. {insertion_1} And this is also some text. {insertion_2}'

replacements = {
  1 => 'HELLO',
  2 => 'WORLD',
}

str.gsub(/\{insertion_(\d*)\}/) {
  id = $1.to_i
  replacements[id]
}
# => "This is some text. HELLO And this is also some text. WORLD" 

Just replace the block body with whatever you need to do. 🙂

(Sidenote: \d+ is a better choice than \d* for matching numbers.)