Data::Page on PHP

gistfile1.aw

<?php

// Pager Data Container
class DataPage{
  private $total_entries;
  private $entries_per_page;
  private $current_page;

  function __construct($total_entries,$entries_per_page,$current_page){
    $this->total_entries($total_entries ?: 0);
    $this->entries_per_page($entries_per_page ?: 10);
    $this->current_page($current_page ?: 1);
  }

  // accessor
  public function total_entries(){
    if (func_num_args() > 0){
      $x = func_get_arg(0);
      $this->total_entries = $x;
      return $x;
    }
    return $this->total_entries;
  }

  public function entries_per_page(){
    if (func_num_args() > 0){
      $x = func_get_arg(0);
      if ($x < 0){die('entries_per_page must be positive value');}
      $this->entries_per_page = $x;
      return $x;
    }
    return $this->entries_per_page;
  }

  public function current_page(){
    if (func_num_args() > 0){
      $x = func_get_arg(0);
      $this->current_page = $x;
      return $x;
    }
    return $this->current_page;
  }

  // ==== first_page/last_page

  public function first_page(){
    return 1;
  }
  public function last_page(){
    $pages = $this->total_entries() / $this->entries_per_page();
    $last_page = 0;
    
    // ページあたり項目数で割り切れるならそのまま
    $intpages = (int)floor($pages);
    if ($pages === $intpages){
      $last_page = $pages;
    }else{
      $last_page = 1 + $intpages;
    }
    
    if ($last_page < 1){ $last_page = 1;}
    
    return $last_page;
  }

  // ==== first/last : current pageでの最初最後
  public function first(){
    if ($this->total_entries() == 0){
      return 0;
    }else{
      return ((($this->current_page() - 1) * $this->entries_per_page() ) + 1);
    }
  }
  public function last(){
    if ($this->current_page() == $this->last_page()){
      return $this->total_entries();
    }else{
      return ($this->current_page() * $this->entries_per_page());
    }
  }

  public function entries_on_this_page(){
    if ($this->total_entries() == 0){
      return 0;
    }else{
      return $this->last() - $this->first() + 1;
    }
  }
  public function previous_page(){
    $cpage = $this->current_page();
    if ($cpage > 1){
      return $cpage - 1;
    }else{
      return null;
    }
  }
  public function next_page(){
    $cpage = $this->current_page();
    if ($cpage < $this->last_page()){
      return $cpage + 1;
    }else{
      return null;
    }
  }

  // splice: retrieve 'current' items from the given array
  public function splice(){}

  // skipped: 
  public function skipped(){}

  public function change_entries_per_page(){}

  // get navigation
  //  pagenums=(1..10), currentpage=2,
  public function pages_in_navigation($ppn = null){
    $pages_per_navigation = $ppn ?: 10;

    $first_page = $this->first_page();
    $last_page = $this->last_page();
    $current_page = $this->current_page();

    // if the range of navi is all included
    if ($pages_per_navigation >= $last_page){
      return range($first_page, $last_page);
    }

    // otherwise (ex. navi has 5 slots, records require 10 pages)
    $prev = $current_page - 1;
    $next = $current_page + 1;
    $cnt = 0;
    $putcnt = 0;
    $retarr = array($current_page);
    while($putcnt < $pages_per_navigation - 1){
      if ($cnt % 2){ //prev
	if ($first_page <= $prev){
	  array_unshift($retarr, $prev);
	  $putcnt += 1;
	}
	$prev -= 1;
      }else{ //next
	if ($last_page >= $next){
	  array_push($retarr, $next);
	  $putcnt += 1;
	}
	$next += 1;
      }
      $cnt++;
    }

    return $retarr;
  }

  public function first_navigation_page(){
    $arr = $this->pages_in_navigation();
    return $arr[0];
  }
  public function last_navigation_page(){
    $arr = $this->pages_in_navigation();
    return $arr[-1];
  }

}