Wrongful Dismissal should not be confused with Unfair Dismissal, Wrongful Dismissal is based on contract law. Any claim for Wrongful Dismissal will therefore mean looking at the employee's employment contract to see if the employer has broken the contract.
Note that the absence of a formal written contract of employment does not preclude a claim for wrongful dismissal, as a de facto contract is taken to exist by virtue of the employment relationship.
The most common breach is where the employee is dismissed without notice or the notice given is too short. Obviously either party can end the employment relationship if they give the necessary notice. This will either be the legal minimum or what is stated in the employee's contract.