.. _orm1-exercise-solutions: Exercise Solutions: OMG the ORM! ================================ .. _orm1-exercise-solutions-class: The ``EventCategory`` Class --------------------------- First, create a new class called ``EventCategory`` in the ``models`` directory. ``EventCategory`` needs to have the following: #. An ``id`` field of type ``int``. #. A ``name`` field of type ``String``. #. A constructor. #. The appropriate getters and setters. ``EventCategory`` represents data that will be stored in our database, so you need to use the ``@Entity`` annotation! .. sourcecode:: java :linenos: @Entity public class EventCategory { @Id @GeneratedValue private int id; @Size(min=3, message="Name must be at least 3 characters long") private String name; public EventCategory(@Size(min = 3, message = "Name must be at least 3 characters long") String name) { this.name = name; } public EventCategory() {} public String getName() { return name; } public void setName(String name) { this.name = name; } public int getId() { return id; } @Override public String toString() { return name; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; EventCategory that = (EventCategory) o; return id == that.id; } @Override public int hashCode() { return Objects.hash(id); } } :ref:`Back to the exercises ` .. _orm1-exercise-solutions-methods1: The ``EventCategoryController`` Class ------------------------------------- ``displayAllEvents`` ^^^^^^^^^^^^^^^^^^^^ ``displayAllEvents`` needs to do the following: #. Use ``@GetMapping`` and return ``"eventCategories/index"``. #. Add an attribute for the ``title`` that uses ``"All Categories"``. #. Add an attribute for the ``categories`` that uses all of the values in your ``EventCategoryRepository`` variable. .. sourcecode:: java :linenos: @GetMapping public String displayAllCategories(Model model) { model.addAttribute("title", "All Categories"); model.addAttribute("categories", eventCategoryRepository.findAll()); return "eventCategories/index"; } :ref:`Back to the exercises ` .. _orm1-exercise-solutions-methods3: ``processCreateEventCategoryForm`` ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ``processCreateEventCategoryForm`` needs to do the following: #. Use ``@PostMapping``. #. Use error validation and the ``Errors`` object appropriately. If you want to review how to use the ``Errors`` object, check out the section on :ref:`error validation `. #. Add an attribute for the ``title`` and assign it ``"Create Category"``. #. Add an attribute for a new instance of ``EventCategory``. #. Either return ``"eventCategories/create"`` or ``"redirect:"``. .. sourcecode:: java :linenos: @PostMapping("create") public String processCreateEventCategoryForm(@Valid @ModelAttribute EventCategory eventCategory, Errors errors, Model model) { if (errors.hasErrors()) { model.addAttribute("title", "Create Category"); model.addAttribute(new EventCategory()); return "eventCategories/create"; } eventCategoryRepository.save(eventCategory); return "redirect:"; } :ref:`Back to the exercises ` .. _orm1-exercise-solutions-templates: Thymeleaf Templates ------------------- To finish the exercises, we need to make two new templates. #. ``eventCategories/index``, which will contain a table of the event categories. .. sourcecode:: html :linenos:

Category Name

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