Lift Framework example source code file (Paginator.scala)

This example Lift Framework source code file (Paginator.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lift Framework tags/keywords

mappedfield, mappedfield, mapper, mapper, mapperpaginator, maxrows, metamapper, metamapper, orderby, seq, startat, string, t, t

The Lift Framework Paginator.scala source code

/*
 * Copyright 2009-2011 WorldWide Conferencing, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.liftweb
package mapper
package view

import scala.xml.{NodeSeq, Text, Elem}
import net.liftweb.common.Loggable
import net.liftweb.http.{S,DispatchSnippet,Paginator,PaginatorSnippet,
  SortedPaginator,SortedPaginatorSnippet}
import net.liftweb.http.S.?
import net.liftweb.util.Helpers._
import net.liftweb.mapper.{Mapper, MetaMapper, MappedField,
         QueryParam, OrderBy, StartAt, MaxRows, Ascending, Descending}

/**
 * Helper for when using paginators with a ModelSnippet.
 * Adds a dispatch that delegates the "paginate" snippet to the paginator member.
 * @author nafg and Timothy Perrett
 */
trait PaginatedModelSnippet[T <: Mapper[T]] extends ModelSnippet[T] {
  abstract override def dispatch: DispatchIt = super.dispatch orElse Map("paginate" -> paginator.paginate _ )
  /**
   * The paginator to delegate to
   */
  val paginator: PaginatorSnippet[T]
}

/**
 * Paginate mapper instances by supplying the model you
 * wish to paginate and Paginator will run your query for you etc.
 *
 * @param meta The singleton of the Mapper class you're paginating
 * @author nafg and Timothy Perrett
 */
class MapperPaginator[T <: Mapper[T]](val meta: MetaMapper[T]) extends Paginator[T] {
  /**
   * QueryParams to use always
   */
  var constantParams: Seq[QueryParam[T]] = Nil

  def count = meta.count(constantParams: _*)
  def page = meta.findAll(constantParams ++ Seq[QueryParam[T]](MaxRows(itemsPerPage), StartAt(first)): _*)
}

/**
 * Convenience class that combines MapperPaginator with PaginatorSnippet
 * @param meta The singleton of the Mapper class you're paginating
 */
class MapperPaginatorSnippet[T <: Mapper[T]](meta: MetaMapper[T])
  extends MapperPaginator[T](meta) with PaginatorSnippet[T]

/**
 * Implements MapperPaginator and SortedPaginator.
 * @param meta The singleton of the Mapper class you're paginating
 * @param initialSort The field to sort by initially
 * @param _headers Pairs of column labels and MappedFields.
 */
class SortedMapperPaginator[T <: Mapper[T]](meta: MetaMapper[T],
                                initialSort: net.liftweb.mapper.MappedField[_, T],
                                _headers: (String, MappedField[_, T])*)
    extends MapperPaginator[T](meta) with SortedPaginator[T, MappedField[_, T]] {

    val headers = _headers.toList
    sort = (headers.indexWhere{case (_,`initialSort`)=>true; case _ => false}, true)

    override def page = meta.findAll(constantParams ++ Seq[QueryParam[T]](mapperSort, MaxRows(itemsPerPage), StartAt(first)): _*)
    private def mapperSort = sort match {
      case (fieldIndex, ascending) =>
        OrderBy(
          headers(fieldIndex) match {case (_,f)=>f},
          if(ascending) Ascending else Descending
        )
    }
}

/**
 * Convenience class that combines SortedMapperPaginator and SortedPaginatorSnippet.
 * @param meta The singleton of the Mapper class you're paginating
 * @param initialSort The field to sort by initially
 * @param headers Pairs of column labels and MappedFields.
 */
class SortedMapperPaginatorSnippet[T <: Mapper[T]](
  meta: MetaMapper[T],
  initialSort: net.liftweb.mapper.MappedField[_, T],
  headers: (String, MappedField[_, T])*
) extends SortedMapperPaginator[T](meta, initialSort, headers: _*)
  with SortedPaginatorSnippet[T, MappedField[_, T]]