Empty parameter in meta_value - php

Question

I have a option, where the user can add alert message, and when the page is Loaded, it should be displayed. The problem is that the alert is displayed, but withoud the message, that the user writes and im not sure why.
if( !empty( $postdata ) ) {
foreach( $postdata as $dx_section ) {
var_dump( $dx_section );
foreach ( $dx_section->column_array as $value ) {
if ( $value->column_view == 'alert' && $value->column_indx == $id ) {
$column_data = isset( $value->column_data ) ? $value->column_data : "";
$column_alert = isset( $value->column_alert ) ? $value->column_alert : "";
if ( $column_alert == 'On Page Load' ) {
if (isset( $column_data )) {
echo '<script>alert( "' . $column_data . '" )</script>';
}
} else if ( isset( $value->column_alert_ids ) ) {
$id_array = explode( " ", $value->column_alert_ids );
echo '<script>';
foreach ( $id_array as $key ) {
echo 'jQuery(document).ready(function($){
$(document).find("#' . $key . '").click(function() {
alert("' . $column_data . '");
} );
} );';
}
echo '</script>';
}
}
}
}
}
The column_data is empty, it should be the message.
Here is the dumped $dx_section variable
object(stdClass)[258]
public 'section_order' => int 1
public 'section_name' => string 'First Section Name' (length=18)
public 'section_classes' => string 'Section Classes' (length=15)
public 'section_margin' => string '' (length=0)
public 'section_padding' => string '' (length=0)
public 'column_array' =>
array (size=2)
0 =>
object(stdClass)[257]
public 'row_class' => string '' (length=0)
public 'column_name' => string 'Alert Window 1' (length=14)
public 'column_size' => string '12' (length=2)
public 'col_class' => string 'Column Classes' (length=14)
public 'column_view' => string 'alert' (length=5)
public 'column_indx' => int 1
public 'column_alert' => string 'On Page Load' (length=12)
public 'column_alert_ids' => string '' (length=0)
public 'column_data' => string '' (length=0)
public 'extension_data' =>
object(stdClass)[595]
...
1 =>
object(stdClass)[596]
public 'row_class' => string '' (length=0)
public 'column_name' => string 'Custom Text' (length=11)
public 'column_size' => string '12' (length=2)
public 'col_class' => string 'Column Classes' (length=14)
public 'column_view' => string 'custom_text' (length=11)
public 'column_indx' => int 2
public 'column_class' => string '' (length=0)
public 'column_padding' => string '' (length=0)
public 'column_padding_type' => string '' (length=0)
public 'column_background' => string '' (length=0)
public 'column_boder' => string '' (length=0)
public 'column_data' => string '<p><strong>Custom data...</strong></p>
' (length=39)
public 'extension_data' =>
object(stdClass)[594]
...