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Undoubtedly, pagination is one of the most usefull CodeIgniter features. But this feature has lack of flexibility. Page number usualy put in a segment of a URI. So, if we use non-fixed query criteria, the URI segment number will change. It still can work this way, but surely too many conditions.

In this article i will show you how to trick it.

Imagine we have a car search page. The query criteria are `brand`, `year`, `style`, `start-price-range`, `stop-price-range`.

Original URI will be like this :

http://localhost:80/car/search/Toyota/2005/SUV/50000/85000/1
class_name : car
method_name : search
brand : Toyota
year : 2005
style : SUV
start-price-range : 50000
stop-price-range : 85000
page_number : 1

In that URI, page number is in uri_segment(8). But what if we don’t care about the brand and the style, the uri_segment for page_number will change and it is quite difficult to determine what criteria will be ignored.

Off course we still can make it work by put default value for ignored criteria, example :

http://localhost:80/car/search/unset/2005/unset/50000/85000/1
class_name : car
method_name : search
brand : unset -> don’t bother use it in query
year : 2005
style : unset -> don’t bother use it in query
start-price-range : 50000
stop-price-range : 85000
page_number : 1

This will work, but i will offer you a better way.

I will use this URI.

http://localhost:80/car/search/brand_Toyota__year_2005__style_SUV__start-price-range_50000__stop-price-range_85000/1
class_name : car
method_name : search
criteria : brand_Toyota__year_2005__style_SUV__start-price-range_50000__stop-price-range_85000
page_number : 1

In that URI page number is in uri_segment(4), and will allways in uri_segment(4) no matter how many criteria i added. Or i can ignored all criteria by using this URI

http://localhost:80/car/search/all/1

What we need is just to parse the criteria. Criteria to criteria separated by `__` and criteria to criteria-value separated by `_`. Here is the parsing function, you can put it in a helper or in a `car` controller itself.

<?php

function parsing_criteria($pairs){
    $criteria = array();
    if($pairs!=’all’){
        $pairs = explode("__",$pairs);
        foreach($pairs as $row){
            $array_row = explode("_",$row);
            $criteria[$array_row[0]] = $array_row[1];
        }
    }
    return $criteria;
}

?>

If you parse `pairs of criteria` above with function `parsing_criteria` will results an array below

Array
(
[brand] => Toyota
[year] => 2005
[style] => SUV
[start-price-range] => 50000
[stop-price-range] => 85000
)

The `search` method in the `car` class will look like this

<?php
—
// others methods
—
    function search($criteria=’all’){
        $this->load->library(‘pagination’);
        $this->load->helper(‘car’); /*i put function parsing_criteria here*/
        –
        –
        –
        $pagination_per_page = 10;
        $pagination_uri_segment = 4;
        $pagination_pageno = $this->uri->segment(4)==” ? 1 : $this->uri->segment(4);

        /* i put parsing_criteria in a helper
        $option will contain array of criteria*/
        $option = parsing_criteria($criteria);

        /* add `start` and `count` to $option array for the sql query*/
        $option['start'] = $pagination_pageno – 1;
        $option['count'] = $pagination_per_page;
       
        $config = array(
            ‘base_url’ => ‘/car/search/’ . $criteria . "/",
           
            /* call some model using $option (array) to be used in sql query */
            ‘total_rows’ => $this->car_model->count_car($option),
           
            ‘per_page’ => $pagination_per_page,
            ‘uri_segment’=> $pagination_uri_segment
        );
        $this->pagination->initialize($config);

        /* call some model using $option (array) to be used in sql query */
        $data['car'] = $this->car_model->search_car($option));

        $data['pagination_links'] = $this->pagination->create_links();
        –
        –
        –
    }
—
// others methods
—

?>

By using this trick I can use multiple and unlimited criteria. Oops, off course it is limited, because HTTP $_GET has limitation too.
Hope you not having difficulty to understand my english, since I have. Happy coding

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