how to pass an array with N arguments to a bind_param within a class?

Question

I’m trying to develop a global class for pagination

Follow the code:

class Pager {
private $Sql;
private $Limit;
private $ArgType;
private $Page;
private $Arguments;
private $ArgNumber;
private $Connect;
private $result=array();
public function setSql($Sql){
    $this->Sql=$Sql;
    return false;
}
public function setLimit($Limit){
    $this->Limit=$Limit;
    return false;
}
public function setArguments(){
    $this->Arguments=func_get_args();
    $this->ArgNumber=func_num_args();
    return false;
}
public function setArgType($ArgType){
    $this->ArgType=$ArgType;
    return false;
}
public function setConnect($Connect){
    $this->Connect=$Connect;
    return false;
}
public function setPage($Page){
    $this->Page= isset($Page)?$Page:1;
    return false;
}
private function countRegister(){
    $Pager = $this->Connect->prepare($this->Sql);
    switch ($this->ArgNumber){
        case 1:
            $Pager->bind_param($this->ArgType,$this->Arguments[0]);
        break;
        case 2:
            $Pager->bind_param($this->ArgType,$this->Arguments[0],$this->Arguments[1]);
        break;
        case 3:
            $Pager->bind_param($this->ArgType,$this->Arguments[0],$this->Arguments[1],$this->Arguments[2]);
        break;
        case 4:
            $Pager->bind_param($this->ArgType,$this->Arguments[0],$this->Arguments[1],$this->Arguments[2],$this->Arguments[3]);
        break;
        case 5:
            $Pager->bind_param($this->ArgType,$this->Arguments[0],$this->Arguments[1],$this->Arguments[2],$this->Arguments[3],$this->Arguments[4]);
        break;
    }
    $Pager->execute();
    $Pager->store_result();
    return $Pager->num_rows;
    $Pager->close();
}
private function countPages($NumReg){
    return ceil($NumReg/$this->Limit);
}
private function prevPage(){
    if($this->Page>1)
        return $this->Page-1;
    else
        return false;
}
private function nextPage(){
    if($this->Page<$this->result['Pages'])
        return $this->Page+1;
    else
        return false;
}
private function getStart(){
    return ($this->Page-1)*$this->Limit;
}
public function execPager(){
    $this->result['Pages'] = $this->countPages($this->countRegister());
    $this->result['PrevPage'] = $this->prevPage();
    $this->result['NextPage'] = $this->nextPage();
    $this->result['Start'] = $this->getStart();
    $this->result['Limit'] = $this->Limit;
    return false;
}
public function getPager(){
    return $this->result;
}

}

But in the private function execPage() I don’t see a way to do the bind_param with the array who picked up the function setArguments the only way was using a case with predefined possibilities

Any suggestions on how to pass these parameters to the function and be able to perform in this way?

I am using mysqli and the class is in early stage in function setArgument I’ll pass N arguments and put the argument type by the function setArgType and the same will be a string then I’ll put it inside the bind_param thus

$Pager->bind_param($this->setArgType, [Todos os N argumentos da setArguments]);

Answer 1

I won’t go into the merit of responsibility of objects because that is not the purpose of the question but what you have implemented does not make sense.

Your class has none Setter, public method for which data can be defined for the working class. The closest one would be the getArguments() that hints that something will be returned and not definite.

In addition to all the various changes you will need to make this class plausible to use would be something like this:

class Paginador {

    // ...

    private $arguments = array();

    public function setArguments( $argument, $value ) {

        $this -> arguments[ $argument ] = $value;
    }

    public function getAruments() {
        return $this -> arguments;
    }

    // ...
}

Once this is done, your class can already be manipulated externally through the object instance.

Now, as to the scope of the question.

First you have to define where this bind_param will come. Are you from an outside class? From a native class?

Assuming your answer is PDO you must first prepare the statement, that is, the SQL string and itself, defining the proper ones placehodlers, are named (preceded by colons) or indexed (questions only) and, in their method execPage() you iterate the arguments of your argument property and with each iteration you link the new argument:

class Paginador {

    // ...

    private function execPage() {

        // Prepare statement

        foreach( $this -> arguments as $argument => $value ) {

            if( is_string( $value ) && ! is_numeric( $value ) ) {

                $dataType = PDO::PARAM_STR;

            } else {

                $dataType = PDO::PARAM_INT;
            }

            $stmt -> bindParam( $argument, $value, $dataType );
        }
    }

    // ...
}

The didactic example above assumes that the statement prepared be in the variable $stmt

That’s basically it, but you REALLY need to study Object Orientation better because just throwing ideas into a class is not OOP.

A tip: Avoid func_get_args() whenever possible. This function should only be used when you REALLY don’t know how many arguments will be told for a given function / method And there is no other better way to do it.

in this scenario, the best way to do it would be to inform an array with key/value pairs or use Fluent Interfaces.