Pass a class attribute by reference to a local variable

Question

Pass a class attribute by reference to a local variable

Navigation

#1 by (0 votes)

0

How about people! I have a PrintServer with the software PaperCut PrintLogger which generates some CSV (and HTML) files with the printing log. I'm doing a script that reads the CSV in the data entered into a database, for further analysis.

In the database I have 3 tables: Printer , User and Activity . This last table is related to the other 2 by their id. In another method charge in memory 2 arrays attributes, $this->printers and $this->users with the information of printers (of the table Printers ) and users (table Users ) that are currently in the database (this works perfect ).

Now, for each record of the CSV read, I have a method that verifies that the name of the printer appears in the table " Printer ". If it does not appear, then insert the printer in that table and update $this->printers with that data so that it is not reinserted in subsequent comparisons.

private function check_or_insert_printer_db($value) {
    // Inserta datos nuevos en las tablas de Printer o User
    $key_item = array_search($value, $this->printers);
    if($key_item === False) {
        // Si no se encuentra la impresora, insertarla en la tabla
        $query = "INSERT INTO Printer (prname) VALUES ('$value')";
        $this->dbconn->query($query);
        $id_item = $this->dbconn->lastInsertRowid();
        // Actualiza el array para no volver a insertar un elemento nuevo
        $this->printers[$id_item] = $value; 
    } else {
        // Si existe la impresora en la tabla, asignar el valor del id.
        $id_item = $key_item;
    }
    return $id_item; // retorna el ID relacionado
}

This works perfect.

Here comes my problem, which is more a doubt. I wanted the described method to also work for " Users " since it is exactly the same logic as with " Printers ". So I modified the previous method and now I have a local variable, $arr_elements , to which I assign the reference of $this->printers or $this->users , as the case may be.

private function check_or_insert_item_db($value, $table, $column) {
    // Inserta datos nuevos en las tablas de Printer o User
    $arr_elements = ($table == 'Printer') ? &$this->printers : &$this->users;
    $key_item = array_search($value, $arr_elements);
    if($key_item === False) {
        // Si no se encuentra el item, insertarlo en la tabla
        $query = "INSERT INTO $table ($column) VALUES ('$value')";
        $this->dbconn->query($query);
        $id_item = $this->dbconn->lastInsertRowid();
        // Actualiza el array para no volver a insertar un elemento nuevo
        $arr_elements[$id_item] = $value; 
    } else {
        $id_item = $key_item;
    }
    return $id_item; // retorna el ID relacionado
}

But the following error appears.

PHP Parse error: syntax error, unexpected '&'

Can not attributes be assigned by reference to local variables of a method? Is there a better way to solve this issue without having to have two separate methods for each case?

php poo sqlite3

asked by aeportugal 27.10.2018 в 22:47

source

1 answer

Someone who has experience consuming Payment gateway Service of Master card Join fixes in PHP

score 0 · Accepted Answer

I have already found the reason for the problem, and it seems silly, but I was just thinking about it for hours. I leave it as an answer in case someone could do the same to you

I do not know if it will be a PHP feature or bug, or what, but it seems that operador ternario does NOT support assignments by reference. Which is strange since I've assigned much more complex things to them. But hey, it will touch to make a query in the official knowledge base of PHP to see what they say.

So I changed

$arr_elements = ($table == 'Printer') ? &$this->printers : &$this->users;

for

if ($table == 'Printer') {
    $arr_elements = &$this->printers;
} else {
    $arr_elements = &$this->users;
}

And holy remedy.