Take over one of the seven derived routes#

Replace a derived page with one you wrote and keep the other six, or remove an action from a resource altogether.

Write the page, same method, same path#

A handwritten route wins over a derived one on the same method and path. To replace the list page of Book, create app/books/Index.scala:

package app.books

import io.eezo.core.html.*
import io.eezo.db.*
import io.eezo.db.Scopes.read
import io.eezo.http.{Guarded, Request, Response}
import models.{Book, User}

object Index {

  given Guarded[Index.type] = User.guard.required

  def index(request: Request): Response = {
    val books = read(Table[Book].all())
    Response.Ok(
      Html.doctype ++ html(
        head(meta(Attrs.charset := "utf-8"), title("the shelf")),
        body(
          h1("The shelf"),
          ul(books.map(b => li(a(Attrs.href := s"/books/${b.id.value}", b.title), " by ", b.author))),
          p(a(Attrs.href := "/books/new", "Add a book"))
        )
      )
    )
  }
}

(The Guarded line is only needed if the application has a guard.)

$ eezo routes

⚠ GET /books is written by hand and also derived; the handwritten route is served and the derived one is not mounted.
13 routes:
  ...
  GET /books
  ...
  GET /books/new
  GET /books/:id

The derived list page is dropped from the table, your page is served, and the other six are untouched. The warning is there so you know it was deliberate.

Keep the form honest#

If the page you take over is one that renders or reads the form, new, edit, create or update, call the derived Form from your handler instead of writing the inputs by hand:

import io.eezo.http.{Form, Method}

// render it
Form[Book].render(action = "/books", method = Method.POST, value = None, token = request.csrf)

// read it back
request.as[Book] match {
  case Right(book)  => ...
  case Left(errors) => ...
}

The page that emits the inputs and the handler that reads them then can't disagree about field names, and a new field on the case class appears on both without a change here.

Remove an action instead#

To not have a route at all, say so in the model's companion:

import io.eezo.http.{Action, Actions}

object Book {
  given Actions[Book] = Actions.except(Action.Destroy)
}

Actions.except(...) keeps everything but the named ones; Actions.only(...) keeps only the named ones. The derived pages stop linking to a removed action, so a show page without Destroy has no Delete button.

Order and shadowing#

A handwritten route with the same method and path replaces the derived one. A handwritten route that merely overlaps, /books/latest next to /books/:id, is matched first because the table is ordered most specific first, and eezo routes reports the shadow so you can check it's what you meant. Two handwritten routes on one method and path is a boot error.