Bonjour,
j'affiche des graphiques (googlechart) reposant sur une base mysql sur une page html.
j'utilise un picker date pour afficher le graphique selon un jour donné mais lorsque je sélectionne la page au départ, elle est vide tant que je n ai pas sélectionné une date.
j 'aimerai que , lorsque je selectionne la page de graphique temperature alors la courbe des dernieres 24 h s affiche.
merci a vous.

<script type="text/javascript">
      google.charts.load('current', {'packages':['corechart']});
      google.charts.setOnLoadCallback(graphtemp);

      function graphtemp() {
        var data = google.visualization.arrayToDataTable([
          ['Date', 'Température '],


          <?php 
          mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
               if (isset($_POST['selectedatetemp'])) {
                    $timestamp = strtotime($_POST['selectedatetemp']);   
                    $date = date('Y-m-d ', $timestamp);
                    $month = (int) date('n', $timestamp);
                    $year = (int) date('Y', $timestamp);    
   
        
                    $chartQuery = "SELECT  date_format(Date,'%d/%m/%Y %H:%i ') AS 'Update', TmpExt AS TmpExt_Max  FROM ZiMeteo WHERE DATE(Date) = ('$date')  ORDER BY ID DESC LIMIT 144 ";
}                   
                else {
                    $chartQuery = "SELECT  date_format(Date,'%d/%m/%Y %H:%i ') AS 'Update', TmpExt AS TmpExt_Max  FROM ZiMeteo WHERE DATE(Date) = ('$date')  ORDER BY ID DESC LIMIT 144 ";

}

           $chartQueryRecords = mysqli_query($connect, $chartQuery);
                mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
                 

                    while ($row = mysqli_fetch_assoc($chartQueryRecords)) {
                         echo "['".$row['Update']."',".$row['TmpExt_Max']."],";
                    }
 
           ?>
           ]);

        var options = {
            
            
            explorer: {
                axis: 'horizontal',
                keepInBounds: true,
                maxZoomIn: 4.0
          },
            series: {
                0: { color: '#D80010' },
                1: { color: 'blue' },
                
        },
            backgroundColor: 'transparent',
            color: ['white'],
            lineWidth: 4,
            hAxis: { direction: -1,
                     format:'MMM d, y',

                     textStyle: {
                     color:'white'
                              },
         

                          },
            vAxis: { 
                     textStyle: {
                        color:'red',
                     },
            explorer: {
                    axis: 'horizontal',
                    keepInBounds: true,
                    maxZoomIn: 4.0,
                            },        


                 },

            chartArea: {left : 100,
                        width: 1130},
            legend: { position: 'bottom',
                      textStyle: {
                       color: 'white'},
                }
        };

        var chart = new google.visualization.AreaChart(document.getElementById('temp_chart'));

        chart.draw(data, options);
      }
</script>

<form action="temperature.php" method="POST" name="formulaire">
  <input type="date" name="selectedatetemp" defaultDate= "now">
  <input type="submit" value="Go">
</form>

il faut que tu définisse une date par défaut avant ton if(isset(...

tes variables $month et $year sont inutile, tu ne les utilise pas.

Bonjour. Comment je fait ca ? je n ai aucune idee de comment le realiser ?

a priori je modifierai le php comme ceci

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
               $date = date('Y-m-d ');
               if (isset($_POST['selectedatetemp'])) {
                    $timestamp = strtotime($_POST['selectedatetemp']);   
                    $date = date('Y-m-d ', $timestamp);
                    $month = (int) date('n', $timestamp);
                    $year = (int) date('Y', $timestamp);    
   
        
                    $chartQuery = "SELECT  date_format(Date,'%d/%m/%Y %H:%i ') AS 'Update', TmpExt AS TmpExt_Max  FROM ZiMeteo WHERE DATE(Date) = ('$date')  ORDER BY ID DESC LIMIT 144 ";
}                   
                else {
                    $chartQuery = "SELECT  date_format(Date,'%d/%m/%Y %H:%i ') AS 'Update', TmpExt AS TmpExt_Max  FROM ZiMeteo WHERE DATE(Date) = ('$date')  ORDER BY ID DESC LIMIT 144 ";

}

           $chartQueryRecords = mysqli_query($connect, $chartQuery);
                mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
                 

                    while ($row = mysqli_fetch_assoc($chartQueryRecords)) {
                         echo "['".$row['Update']."',".$row['TmpExt_Max']."],";
                    }
 

ainsi $date a la valeur du jour sauf si le formulaire en donne une autre