[JAVA] Play Framework Study Momo DB Update

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How to update an entity

Rough flow

The simplest method is as follows

1. Search by ID
2. Update the input contents

code

** Search for the entity to be updated by ID **

「routes」

GET     /item                       controllers.Application.setitem()

「Conotrller (Application.java)」 -Call View to create an input form.

	public static Result setitem() {
		Form<Message> f = new Form(Message.class);
		return.ok(item.render("Enter your ID number.",f));
	}

「View (item.scala.html)」 -Render the screen structure of the input form ・ When you press the send button, the data will be sent to edit. ・ Originally, name and message do not need to be entered this time, but since they are required input items due to annotation, they can be hidden.

@(msg:String,form1:Form[models.Message])//Give form1 a form function

@main("Sample Page"){

    <h1>input ID Number</h1>
    <p>@msg</p>
    @helper.form(action = routes.Application.edit){

      @(helper.inputText(
        field = form1("id")//Form is output
      ))
      <input type="hidden" value = "dummy" name="name"/>
      <input type="hidden" value = "dummy" name="message"/>

      <input type="submit">
    }
}

** Enter the content to be updated **

「routes」

POST    /edit                       controllers.Application.edit()

「Conotrller (Application.java)」 -Call view and render the input state of the entity hit by ID search.

	public static Result edit() {
		Form<Message> f = new Form(Message.class).bindFromRequest();
		if (!f.hasErrors()) {
			Message obj = f.get();//obj contains the entered value
			Long id = obj.id;//Extract id from obj
			obj = Message.find.byId(id);//Search for an entity by id and enter the search result in obj
			if (obj != null) {
				f = new Form(Message.class).fill(obj);//Include the entered entity in the Form
				return ok(edit.render("ID=" + id + "Edit the post.", f));
			} else {
				return ok(item.render("ERROR:ID post not found.", f));
			}
		} else {
			return ok(item.render("ERROR:There is a problem with the input.", f));
		}
	}

「View (edit.scala.html)」 -Render the screen structure of the input form with the entity entered -When the send button is pressed, data is sent to update.

@(msg:String,form1:Form[models.Message])

@main("Sample page"){

   <h1>Update Data</h1>
   <p>@msg</p>
   @helper.form(action=routes.Application.update){
      <input type="hidden" value="@form1("id").value" name="id"/>//Specifying the entity to be updated

      @(helper.inputText(
          field = form1("name")
      ))

      @(helper.inputText(
          field = form1("mail")
      ))

      @(helper.textarea(
          field = form1("message")
      ))

      <input type="submit">
   }
}

** Update the entered data **

「routes」

POST    /update                     controllers.Application.update()

「Conotrller (Application.java)」 ・ Update the data and move to the first screen with return

	public static Result update() {
		Form<Message> f = new Form(Message.class).bindFromRequest();
		if (!f.hasErrors()) {
			Message data = f.get();
			data.update();
			return redirect("/");
		} else {
			return ok(edit.render("ERROR:Please enter again.", f));
		}
	}

How to delete an entity

** Delete reception screen **

「routes」

GET     /del                        controllers.Application.delete()
POST    /remove                     controllers.Application.remove()

「Conotrller (Application.java)」

	public static Result delete() {
		Form<Message> f = new Form(Message.class);
		return ok(delete.render("Number to delete", f));
	}
}

「View (delete.scala.html)」 -Render the deletion reception screen ・ When the send button is pressed, the data is sent to remove.

@(msg:String,form1:Form[models.Message])

  @main("Sample Page"){

    <h1>delete data</h1>
    <p>@msg</p>
    @helper.form(action = routes.Application.remove){

      @(helper.inputText(
          field = form1("id")
      ))

    <input type="hidden" value="dummy" name="name"/>
    <input type="hidden" value = "dummy" name="message"/>

    <input type="submit">
  }
}

** Delete process **

	public static Result remove() {
		Form<Message> f = new Form(Message.class).bindFromRequest();
		if (!f.hasErrors()) {
			Message obj = f.get();
			Long id = obj.id;
			obj = Message.find.byId(id);
			if (obj != null) {
				obj.delete();
				return redirect("/");
			} else {
				return ok(delete.render("ERROR:The ID number cannot be found.", f));
			}
		} else {
			return ok(delete.render("ERROR:There was an error in the input", f));
		}
	}