kacperfkorban/beholder

Small slick lib for create views on on database

Beholder: Play-Slick library for data presentation

Standard part of many application are list of data that is not a effect of simple query from one table but junction and aggregation of data from many tables. Beholder provides support for such elemets.

Features:

• views as table
• declaring filters for data
• support for sorting, filtering on multiple (custom) datatypes

Contributors

Authors:

• Krzysztof Romanowski
• Jerzy Müller
• Mikołaj Jakubowski
• Krzysztof Borowski

Feel free to use it, test it and to contribute!

Getting beholder

For latest version (Scala 2.13.0 compatible) use:

// https://mvnrepository.com/artifact/org.virtuslab/beholder
libraryDependencies += "org.virtuslab" %% "beholder" % "1.4.2"

Or see Maven repository for 2.10, 2.11, 2.12 and 2.13.

Or see our mvnrepository page.

Examples

Lets assume that we created simple entries

case class MachineId(id: Long) extends AnyVal with BaseId

case class UserId(id: Long) extends AnyVal with BaseId

and junction table joined them by ids.

Defining view

Usually for data in view does not came form single table so we have to create view that is materialisation of some query. Beholder provides such utility. We can create Slick's table that operate on view (it is read only).

case class UserMachineView(email: String, system: String, cores: Int)

val usersMachinesQuery = for {
  user <- Users
  userMachine <- UserMachines if user.id === userMachine.userId
  machine <- Machines if machine.id === userMachine.machineId
} yield (user, machine)


val UsersMachineView = FilterableViews.createView(name = "USERS_MACHINE_VIEW",
  apply = UserMachineView.apply _,
  unapply = UserMachineView.unapply _,
  baseQuery = usersMachinesQuery) {
  case (user, machine) =>
    //naming the fields
    ("email" -> user.email,
      "system" -> machine.system,
      "cores" -> machine.cores)
}

UsersMachineView.viewDDL.create

Defining filter

We create a filter by specify table query (view or normal table) and mapping for field

val UsersMachineFilter = new FiltersGenerator[UserMachineView].create(view,
  inText,
  inText,
  inIntField
)

Do the filtering from request

UsersMachineFilter.filterForm.bindFromRequest().fold(
  errors => handleError(),
  filterData => showResult(UsersMachineFilter.filter(filterData))
)