Question

Okay, so I know that using eval() isn’t great, but I haven’t been able to come up with a better solution to my problem, and until recently, there wasn’t a performance reason not to use it. However, I am now passing enough data to the function that it is taking unacceptably long.

The function that is being called is:

public static function makeAMultiDimensionalArrayWithSumsBasedOnMultipleFields($inArray, $dimensionFieldNames, $sumFieldNameArray, $staticFieldNameArray = array())
{
    $outArray = array();

    // Just in case the array has indices, sort it so array_pop works as expected.
    ksort($dimensionFieldNames);

    foreach ($inArray as $row)
    {
        // make sure each row in the inArray has all keys specified by $dimensionFieldNames
        $allFieldsPresent = TRUE;
        foreach ($dimensionFieldNames as $keyFieldName)
        {
            if (!array_key_exists($keyFieldName, $row))
            {
                // Note that alternatively we could set the field to a specified default value.
                $allFieldsPresent = FALSE;
            }
        }

        if ($allFieldsPresent)
        {
            $indexString = '';
            $keyFieldNameArrayCopy = $dimensionFieldNames;

            foreach ($dimensionFieldNames as $keyFieldName)
            {
                $indexString .= "['" . $row[$keyFieldName] . "']";
                // lets sum values
                foreach ($sumFieldNameArray as $sumFieldName)
                {
                    eval ('$outArray' . $indexString . '[' . $sumFieldName . '] += $row[' . $sumFieldName . '];');
                }

                foreach ($staticFieldNameArray as $staticFieldName)
                {
                    eval ('$outArray' . $indexString . '[' . $staticFieldName . '] = $row[' . $staticFieldName . '];');
                }
            }
        }

    }
    return $outArray;
}

It is being called like this:

makeAMultiDimensionalArrayWithSumsBasedOnMultipleFields($data, $dimensionArray, $sumArray, $staticArray);

And the variables being passed to the function are similar to:

$dimensionArray = array("firstLevelID", "secondLevelID", "thirdLevelID", "fourthLevelID", "fifthLevelID");
$sumArray = array("revenue", "cost", "profit", "sales", "inquires", "cost", "walkins");
$staticArray = array("date", "storeID", "storeName", "productID", "productName", "managerID", "managerName", "salesperson");

So I want to rewrite the function so that I’m not using eval() any more. I’ve spent a considerable amount of time on this, and feel that it’s time to seek some advice.

The goal is to take an array of arrays, and turn it into a multidimensional array based on the dimensions in the $dimensionArray.

I don’t want to bore you with too many details right now, so please ask if you need more or have any other questions

Answer 1

Wow, okay. First time through I missed your indexing concatenation. Try this:

if ($allFieldsPresent) {
    $keys = array();
    foreach ($dimensionFieldNames as $keyFieldName) {
        $keys[] = $row[$keyFieldName];
        // lets sum values
        foreach ($sumFieldNameArray as $sumFieldName)
            self::deepAssign($outArray, $keys, $sumFieldName, $row[$sumFieldName], true);
        foreach ($staticFieldNameArray as $staticFieldName)
            self::deepAssign($outArray, $keys, $staticFieldName, $row[$staticFieldName]);
    }
}

protected static function deepAssign(&$array, $keys, $fieldName, $value, $sum = false) {
    $target =& $array;
    foreach ($keys as $key) {
        if (!isset($target[$key]))
            $target[$key] = array();
        $target =& $target[$key];
    }
    if($sum)
        $target[$fieldName] += $value;
    else
        $target[$fieldName] = $value;
}