使用日历库codeigniter在顶部显示前三个和下一个箭头的3个月日历：上一个按钮的问题

Question

I am using Codegniter Calendar library to display three months calendar in one shot (page) with previous and next buttons at the top of the page .

My Issue : Its working fine with "Next" button , but with "Previous" button , I am unable to "decrement the year".

ie , Initially , on the first page , it shows calendar from [March 2019-May 2019] , on clicking "Next" button , it shows calendar from [June 2019- August 2019] : working fine.

But when you click the "Previous" button , it shows calendar of the months [Feb 2019,Jan 2019, March 2019 ]. It should be December 2018 instead of March 2019 .

Here is my Code:

application/controllers/Calendar_controller1.php

public function display($year=null,$month=null){


    if(!$year){

        $year = date('Y');

    }

    if(!$month){

        $month = date('m');
    }

    $this->load->model("cal_model1");
    $data["cur_month_calendar"] = $this->cal_model1->generate($year,$month);
    $data["cur_month1_calendar"] = $this->cal_model1->generate($year,$month+1);
    $data["cur_month2_calendar"] = $this->cal_model1->generate($year,$month+2);

    $data["year"] = $year;
    $data["nxt_month"] = $month+2;
    $data["prev_month"] = $month;


    $this->load->view("cal_view1",$data);
}


 public function build_next_display(){


    $varCurMonth = $this->input->post('month');
    $varCurYear = $this->input->post('year');
    $this->load->model("cal_model1");
     $data["nxt_month1"] = $this->cal_model1->generate($varCurYear,$varCurMonth+1);
    $data["nxt_month2"] = $this->cal_model1->generate($varCurYear,$varCurMonth+2);
    $data["nxt_month3"] = $this->cal_model1->generate($varCurYear,$varCurMonth+3);

    $data["year"] = $varCurYear;
    $data["month"] = $varCurMonth+3;

    //$this->load->view("cal_view1",$data); 

    echo json_encode($data);
} 


     public function build_prev_display(){


    $varCurMonth = $this->input->post('month');
    $varCurYear = $this->input->post('year');
    $this->load->model("cal_model1");
     $data["nxt_month1"] = $this->cal_model1->generate($varCurYear,$varCurMonth-1);
    $data["nxt_month2"] = $this->cal_model1->generate($varCurYear,$varCurMonth-2);
    $data["nxt_month3"] = $this->cal_model1->generate($varCurYear,$varCurMonth-3);

    $data["year"] = $varCurYear;
    $data["month"] = $varCurMonth-1;

    //$this->load->view("cal_view1",$data); 

    echo json_encode($data);
} 

application/models/Cal_model1.php

public  $conf = array();

public function __construct(){



    $this->conf = array(
                'start_day' => 'monday',
                //'show_next_prev' => true,
                //'next_prev_url' => base_url().'Calendar_Controller/display',
                'day_type' => 'short'
    );

    $this->conf['template'] = '

    {table_open}<table border="0" cellpadding="0" cellspacing="0" class="calendar">{/table_open}

    {heading_row_start}<tr class="heading">{/heading_row_start}

    {heading_previous_cell}<th><a href="{previous_url}">&lt;&lt;</a></th>{/heading_previous_cell}
    {heading_title_cell}<th colspan="{colspan}">{heading}</th>{/heading_title_cell}
    {heading_next_cell}<th><a href="{next_url}">&gt;&gt;</a></th>{/heading_next_cell}

    {heading_row_end}</tr>{/heading_row_end}

    {week_row_start}<tr class="weekdays">{/week_row_start}
    {week_day_cell}<td>{week_day}</td>{/week_day_cell}
    {week_row_end}</tr>{/week_row_end}

    {cal_row_start}<tr class="days">{/cal_row_start}
    {cal_cell_start}<td class="day">{/cal_cell_start}
    {cal_cell_start_today}<td>{/cal_cell_start_today}
    {cal_cell_start_other}<td class="other-month">{/cal_cell_start_other}

    {cal_cell_content}
        <div class="day_num">{day}</div>
        <div class="content">{content}</div>
    {/cal_cell_content}
    {cal_cell_content_today}
        <div class="day_num highlight">{day}</div>
        <div class="content">{content}</div>
    {/cal_cell_content_today}

    {cal_cell_no_content}
        <div class="day_num">{day}</div>
    {/cal_cell_no_content}
    {cal_cell_no_content_today}
        <div class="day_num highlight">{day}</div>
    {/cal_cell_no_content_today}

    {cal_cell_blank}&nbsp;{/cal_cell_blank}

    {cal_cell_other}
        <div class="day_num">{day}</div>
    {/cal_cel_other}

    {cal_cell_end}</td>{/cal_cell_end}
    {cal_cell_end_today}</td>{/cal_cell_end_today}
    {cal_cell_end_other}</td>{/cal_cell_end_other}
    {cal_row_end}</tr>{/cal_row_end}




    {table_close}</table>{/table_close}
    ';



}


public function startsWith($string, $startString){

    $len = strlen($startString); 
    return (substr($string, 0, $len) === $startString); 

}


public function get_calendar_data($year,$month){

    $varMonthLen = strlen($month);
    if($varMonthLen == 1){
        $month = '0'.$month;
    }
    $this->db->select('holiday_date,holiday_name');
    $this->db->from('holiday_list');
    $this->db->where('country_id',1);
    $this->db->like('holiday_date',"$year-$month",'after');
    $query=$this->db->get();
    //print_r($this->db->last_query());exit;
    //print_r($query->result());


    $cal_data = array();
    foreach($query->result() as $row){
        $holiday_date = substr($row->holiday_date,8,2);

        $startsWithZero = $this->startsWith($holiday_date,"0");

        if($startsWithZero == true){
            $holiday_date = str_replace('0','',$holiday_date);
        }
        $cal_data[$holiday_date] = $row->holiday_name;  
    }



    return $cal_data; //Issue : 01 -09 Dates  , If you change , this to 1 -9 , it works


}


public function generate($year,$month){

    $this->load->library("calendar",$this->conf);
    $cal_data = $this->get_calendar_data($year,$month);
    //print_r($cal_data);
    return $this->calendar->generate($year,$month,$cal_data);
}

application/views/cal_view1.php

 <script src="<?php echo base_url();?>assets/js/jquery.min.js"></script> <script type="text/javascript"> var year = "<?php echo $year; ?>"; var nxtMonth = "<?php echo $nxt_month; ?>"; var prevMonth = "<?php echo $prev_month; ?>"; $('.previous').click(function(){ //alert("previous"); //alert("year"+year); //alert("month"+prevMonth); $.ajax({ url: "<?php echo base_url();?>Calendar_controller1/build_prev_display", type: "POST", data: {'month':prevMonth,'year':year}, dataType: "json", success: function (res) { console.log(res.nxt_month1); $('#cur_month_calendar').html(''); $('#cur_month_calendar').html(res.nxt_month1); $('#cur_month1_calendar').html(''); $('#cur_month1_calendar').html(res.nxt_month2); $('#cur_month2_calendar').html(''); $('#cur_month2_calendar').html(res.nxt_month3); year = res.year; prevMonth = res.month; }, }); }); $('.next').click(function(){ //alert("next"); //alert("year"+year); //alert("month"+nxtMonth); $.ajax({ url: "<?php echo base_url();?>Calendar_controller1/build_next_display", type: "POST", data: {'month':nxtMonth,'year':year}, dataType: "json", success: function (res) { console.log(res.nxt_month1); $('#cur_month_calendar').html(''); $('#cur_month_calendar').html(res.nxt_month1); $('#cur_month1_calendar').html(''); $('#cur_month1_calendar').html(res.nxt_month2); $('#cur_month2_calendar').html(''); $('#cur_month2_calendar').html(res.nxt_month3); year = res.year; nxtMonth = res.month; }, }); }); </script> 

 .calendar{ font-family:Arial; font-size:12px; } table.calendar{ margin:auto; border-collapse:collapse; } .calendar .days td{ width:50px; height:50px; border:2px solid black; padding:4px; vertical-align:top; background-color:#DEF; } .calendar .days td:hover{ background-color:#FFF; } .calendar .weekdays td{ border:2px solid black; padding:2px; text-align:center; background-color : #C0C0C0; } .calendar .heading th{ text-transform:uppercase; font-size:16px; padding:10px; } .calendar .highlight{ font-weight:bold; color:blue; } .calendar .content{ width: 50px; background-color: #bbb; border-radius: 50%; display: inline-block; border: 2px solid green; text-align: center; } a { text-decoration: none; display: inline-block; padding: 8px 16px; } a:hover { background-color: #ddd; color: black; } .previous { background-color: #f1f1f1; color: black; } .next { background-color: #4CAF50; color: white; } 

 <a href="#" class="previous">&laquo; </a> <a href="#" class="next"> &raquo;</a> <?php //echo $calendar; ?> <div id="cur_month_calendar"> <?php echo $cur_month_calendar; ?> </div> <div id="cur_month1_calendar"> <?php echo $cur_month1_calendar; ?> </div> <div id="cur_month2_calendar"> <?php echo $cur_month2_calendar; ?> </div> 

Answer 1

The code below should do what you want, but could be simplified. I wrote this way so you can see how dates work in PHP. For reference, take a look at DateInterval , date_add and date_sub .

public function build_next_display(){

    $varCurMonth = $this->input->post('month');
    $varCurYear = $this->input->post('year');

    $startTimeStamp = strtotime($varCurYear.'/'.$varCurMonth.'/01');
    $interval1 = new DateInterval('P0M');
    $interval2 = new DateInterval('P1M');
    $interval3 = new DateInterval('P2M');

    $Month1 = date_add( $startTimeStamp, $interval1 );
    $Month2 = date_add( $startTimeStamp, $interval2 );
    $Month3 = date_add( $startTimeStamp, $interval3 );

    $this->load->model("cal_model1");
    $data["nxt_month1"] = $this->cal_model1->generate(year($Month1),month($Month1));
    $data["nxt_month2"] = $this->cal_model1->generate(year($Month2),month($Month2));
    $data["nxt_month3"] = $this->cal_model1->generate(year($Month3),month($Month3));
    $data["year"] = year($Month1);
    $data["month"] = month($Month3);

    //$this->load->view("cal_view1",$data); 

    echo json_encode($data);
} 


public function build_prev_display(){


    $varCurMonth = $this->input->post('month');
    $varCurYear = $this->input->post('year');

    $interval1 = new DateInterval('P0M');
    $interval2 = new DateInterval('P1M');
    $interval3 = new DateInterval('P2M');

    $Month1 = date_sub( $startTimeStamp, $interval1 );
    $Month2 = date_sub( $startTimeStamp, $interval2 );
    $Month3 = date_sub( $startTimeStamp, $interval3 );

    $this->load->model("cal_model1");
    $data["nxt_month1"] = $this->cal_model1->generate(year($Month1),month($Month1));
    $data["nxt_month2"] = $this->cal_model1->generate(year($Month2),month($Month2));
    $data["nxt_month3"] = $this->cal_model1->generate(year($Month3),month($Month3));
    $data["year"] = year($Month1);
    $data["month"] = month($Month3);

    echo json_encode($data);
}