POST variable analysis contains JSON format string PHP

Question

I am verifying certain codes that work well and I don't know what else to optimize in them or what other tests to do: in this case it is a php script that takes the data of the $_POST variable analyzes them and converts them into an array, this is since in some cases the post field may contain a JSon string.

I leave a functional example where I have manually set the $_POST variable to do the Demonstration:

https://wtools.io/php-sandbox/bqsT

Original Code example:

<?php
#Example Array
$_POST = array(
 "valor1" => 1200,
 "valor2" => "texto",
 "valor3" => true,
 "valor4" => '{"seclvl_text":"datp","seclvl_boolean":"false"}',
);
#Validate Function for Json
function ValidateJson($Var) {
 if (!is_array($Var)) {
 return ((json_decode($Var) != null) AND (is_object(json_decode($Var)) OR is_array(json_decode($Var)))) ? true : false;
 } else {
 return false;
 }
}
#Parse Function
function buildVirtualData($data) {
 if (is_array($data)) {
 $result = [];
 foreach ($data as $key1 => $val1) {
 $valJson = ValidateJson($val1);
 if ($valJson) {
 $jsonObj = json_decode($val1, true);
 $result[$key1] = buildVirtualData($jsonObj);
 } elseif ($valJson == false && is_array($val1)) {
 foreach ($val1 as $key2 => $val2) {
 $result[$key1][$key2] = buildVirtualData($val2);
 }
 } else {
 if ($val1 === 'true') {
 $val1 = true;
 } else if ($val1 === 'false') {
 $val1 = false;
 }
 $result[$key1] = $val1;
 }
 }
 return $result;
 } else {
 if (ValidateJson($data)) {
 $jsonObj = json_decode($data, true);
 return buildVirtualData($jsonObj);
 } else {
 return $data;
 }
 }
}
# call to Function:
$data = buildVirtualData($_POST);
echo '<pre>';
echo var_dump($data);
echo '</pre>';

this parse have the feature that convert any text true or false to Boolean.

Answer 1

I think you're are definitely on the right track here. I spent a good deal of time trying to refactor, here's what I came up with

#Validate Function for Json
function jsonDecodeAndValidate($var, $assoc = false) {
 if(!is_string($var))
 return false;
 if(!$decoded = json_decode($var, $assoc))
 return false;
 if(!is_object($decoded) && !is_array($decoded))
 return false;
 return $decoded;
}
#Parse Function
function buildVirtualData($data) {
 if (is_array($data) || is_object($data)) {
 foreach ($data as $key1 => $val1) {
 if(is_array($val1)){
 foreach ($val1 as $key2 => $val2) {
 $result[$key1][$key2] = buildVirtualData($val2);
 }
 }
 else if($decoded = jsonDecodeAndValidate($val1)){
 $result[$key1] = buildVirtualData($decoded);
 } else {
 if(in_array($val1, ['true', 'false']))
 $val1 = filter_var($val1, FILTER_VALIDATE_BOOLEAN);
 $result[$key1] = $val1;
 }
 }
 return $result;
 } else {
 if ($decoded = jsonDecodeAndValidate($data, true)) {
 return buildVirtualData($decoded);
 } else {
 return $data;
 }
 }
}

At the very least this will save you some calls to json_decode as the decoding is done once per iteration.

EDIT: I took another stab at it. I think you can boil it down to this.

#decodeand validate
function jsonDecodeAndValidate($var) {
 if(!is_string($var))
 return $var;
 if(!$decoded = json_decode($var, true))
 return $var;
 if(!is_array($decoded))
 return $var;
 return $decoded;
}
#Parse Function
function buildVirtualData($data, &$build) {
 $data = jsonDecodeAndValidate($data);
 if(is_array($data) || is_object($data)){
 foreach($data as $key => $value){
 buildVirtualData($value, $build[$key]);
 }
 } else {
 if ($data === 'true')
 $data = true;
 if ($data === 'false')
 $data = false;
 $build = $data;
 }
}
# call to Function:
$build = [];
buildVirtualData($_POST, $build);
echo '<pre>';
echo json_encode($build, JSON_PRETTY_PRINT);
echo '</pre>';

You just have to declare your array outside of the function.

• Minos Framework: this trown error: filter_var($data, FILTER_VALIDATE_BOOLEAN)
• Minos Framework: is and error of the website sandbox test... sorry
• Minos Framework: I love it when I see this: &$build optimizing memory usage with pointers.
• Rager: I changed that part back to what it was. Seems you need a module installed to use filter_var

Answer 2

I don't think your JSON validation function is very useful because it does more or less what does the json_decode function itself, except that it tests if the result is an array or an object (that is useless too, since buildVirtualData always uses json_decode with the second parameter set to true and since the $_POST variable can't contain an object but only strings and arrays.).

Always use a strict comparison with null when you want to check the return of json_decode for validity. As a counter-example, elements like an empty string, 0 or false that are valid JSON themselves, return true in this non-strict comparison: var_dump(json_decode('""') == null);

Manualy replacing the strings "true" or "false" with a boolean isn't needed since json_decode does that automatically.

You can rewrite your function like that:

function buildVirtualData($var) {
 if ( is_string($var) ) {
 $json = json_decode($var, true);
 if ( $json !== null )
 $var = $json;
 }
 if ( is_array($var) )
 return array_map('buildVirtualData', $var);
 return $var;
}

demo

• Rager: This wouldn't work if a php object were passed. Or rather, it wouldn't parse it into an array.
• Casimir et Hippolyte: @Rager: a POST variable doesn't contain php object.
• Rager: $_POST = json_decode( <<<JSON { "valor1" : 1200, "valor2: : "texto", "valor3" : true, "valor4" : "{\"seclvl_text\":\"datp\",\"seclvl_boolean\":\"false\"}" } JSON )
• Casimir et Hippolyte: @Rager: are you serious?
• Rager: I guess you're right. $_POST cannot be object.