Pagenumbers CleanupAction

[stefan-kolb]

Replace pages field by num--num or keep existing field if Regex is not matching.
Pages field should only allow page range, i.e. num--num or page set 1,23,35.

Algorithm:

     * Format page numbers, separated either by commas or double-hyphens.
     * Converts the range number format of the <code>pages</code> field to page_number--page_number.
     * Removes all literals except [0-9,-].
     * Keeps the existing String if the resulting field does not match the expected Regex.
     *
     * <example>
     *     1-2 -> 1--2
     *     1,2,3 -> 1,2,3
     *     {1}-{2} -> 1--2
     *     Invalid -> Invalid
     * </example>

[simonharrer]

just return the new value

[stefan-kolb]

We want to return the initial value and not the cleaned value if page numbers regex does not match?!

[simonharrer]

ah ok. then leave this untouched.

[simonharrer]

we should only create the undo action if anything was actually changed (oldValue != newValue).