Array is empty using session variables PHP
I´m having problems passing an array with float values. It´s empty in the other file. Here´s the code. Please any help...
//file 1
session_start();
//...
while ($row = pg_fetch_assoc($sql))
{
$notas[$i] = ($row['grade'] - 57.3)/12;
$i++;
}
print("<FORM method=post action='../indicadores/distr_notas.php'>");
print("<input type=hidden name=notas value='$notas'>");
print("<INPUT type=submit>");
print("</FORM>");
//file 2
session_start();
$_SESSION['notas'] = $_POST['notas'];
$notas = $_SESSION['notas'];
$cant = count($notas);
echo $cant;
I´m still having problems. I think I`m using POST wrong. I have 3 scripts. The first one get the entry, the second one gets the array and the third one shows a graph with the array using jpgraph.
file 1 // get the array
<?php
print("<FORM method=post action='proc_notas.php'>");
print("Codigo de Carrera.<p>");
print("<INPUT type=text name='cod_depto'><p>");
print("<INPUT type=submit>");
print("</FORM>");
?>
//file 2.
if($_SERVER['REQUEST_METHOD'] != "POST")
{
print("<FORM method=post action='normal.php'>");
print("Desviación estándar.<p>");
print("<INPUT type=text name='desviacion'><p>");
print("<INPUT type=submit>");
print("&l开发者_JS百科t;/FORM>");
}
else
{
$depto = $_REQUEST['cod_depto'];
$ordenada = array();
$z = array();
$i = 0;
$suma = 0;
$conectar = new Conector();
$cadena = "select distinct a.grade FROM evaluation_student_evals a inner join td_estudiantes b on a.party_id = b.id_estudiante where b.cod_depto = '$depto' and a.grade >= 0 and a.grade <= 100 order by a.grade ";
$sql = $conectar-> consultas($cadena);
//calcular sigma y miu
$total = pg_num_rows($sql);
$sumanotas = new distribucion();
$totalnotas = $sumanotas -> suma_notas($sql);
$media = $totalnotas/$total;
//Normalizar datos de notas Z = (X-miu)/sigma
while ($row = pg_fetch_assoc($sql))
{
$ordenada[$i] = (1/(12*sqrt(pi())))*(exp(-0.5*(($row['grade']-$media)*($row['grade'] - $media))/($desviacion*$desviacion)));
$i++; }
if (!isset($row))
{
header("Content-Type: text/html");
print("<HTML><HEAD><TITLE>Desempeño de Aprendizaje</TITLE>");
print("</HEAD>");
print("<BODY>");
print("$depto no se encuentra.");
print("</BODY></HTML>");
//file 3 Graph the array
Here, I don´t know how to get the array $ordenada
$_SESSION['notas'][] = ($row['grade'] - 57.3)/12;
This will work with button submission
//file 1
session_start();
//...
while ($row = pg_fetch_assoc($sql))
{
$notas[$i] = ($row['grade'] - 57.3)/12;
$i++;
}
print("<FORM method=post action='../indicadores/distr_notas.php'>");
print("<input type=hidden name=notas value='".implode(',' $notas)."'>"); // use implode to convert array to string
print("<INPUT type=submit>");
print("</FORM>");
//file 2
session_start();
$notas = explode(',' $_POST['notas']); // use explode to convert string to array
$cant = count($notas);
echo $cant;
And this will work with session
//file 1
session_start();
//...
while ($row = pg_fetch_assoc($sql))
{
$_SESSION['notas'][$i] = ($row['grade'] - 57.3)/12;
$i++;
}
print("<FORM method=post action='../indicadores/distr_notas.php'>");
print("<input type=hidden name=notas value='$notas'>"); // no need to use
print("<INPUT type=submit>");
print("</FORM>");
//file 2
session_start();
$notas = $_SESSION['notas'];
$cant = count($notas);
echo $cant;
In the first file you set $notas
array, but in the second you use $_POST['notas']
to add it to session variables, then assign to $notas
. The count in the second file is 0
, because you do not count the elements of array generated in the first file, but instead you count elements of one of the values passed by POST
request (stored in $_POST
array).
To sum up: you create one array, but count elements of different one.
Depending on how you invoke the second file (is it a different request? is it included from the first one?), you have following options:
A. (if it is a different request) Assign $notas
variable to the session array element like that:
// at the end of the first file:
$_SESSION['notas'] = $notas;
and in the second file read from it instead from $_POST['notas']
, or
B. (if the second file is included from the first one) Use the same name of the variable as in the first file ($notas
) and assign it instead of $_POST['notas']
:
// in the second file, instead of " $_SESSION['notas'] = $_POST['notas']; "
$_SESSION['notas'] = $notas;
I wanted to make some calculations to the query result in file 2 before to send it to jgraph at file 3. I still don´t know why this part doen´t work:
//file 2
$depto = $_REQUEST['cod_depto'];
$desviacion = $_REQUEST['desviacion'];
$ordenada = array();
$i = 0;
$suma = 0;
$conectar = new Conector();
$cadena = "select distinct a.grade FROM evaluation_student_evals a inner join td_estudiantes b on a.party_id = b.id_estudiante where b.cod_depto = '$depto' and a.grade >= 0 and a.grade <= 100 order by a.grade ";
$sql = $conectar-> consultas($cadena);
//calcular sigma y miu
$total = pg_num_rows($sql);
$sumanotas = new distribucion();
$totalnotas = $sumanotas -> suma_notas($sql);
$media = $totalnotas/$total;
//Normalizar datos de notas Z = (X-miu)/sigma
while ($row = pg_fetch_assoc($sql))
{
$ordenada[$i] = (1/($desviacion*sqrt(pi())))*(exp(-0.5*(($row['grade']-$media)*($row['grade'] - $media))/($desviacion*$desviacion))); $i++;
}
$tmp= serialize($ordenada);
$tmp= urlencode($tmp);
echo "<form method=post action='../indicadores/distr_notas.php'>";
echo "<input type=hidden name=ordenada value=$tmp>";
echo "<input type=submit name=enviar>";
echo "</form>";
I decide to comment the part "calcular sigma y mui" and now, I can pass the array to file 3.
//file 3
function array_recibe($url_array) {
$tmp = stripslashes($url_array);
$tmp = urldecode($tmp);
$tmp = unserialize($tmp);
return $tmp;
}
$notas =$_REQUEST['ordenada'];
$notas =array_recibe($notas);
//jpgraph code
$graph = new Graph(600,400,"auto");
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