Can't use JSON array in a php loop - php

Question

i have a json file, that has to be parsed in a loop.
i cant seem to succeed
JSON:
{"IMD":{"url":"http:\/\/www.google.com","timeOut":1515155361},"cvH":{"url":"http:\/\/www.google.com","timeOut":1515155364}}
PHP:
<?php
$linkyValues="./linky.json";
if (file_exists($linkyValues)) {
$fileStream = fopen($linkyValues, 'r');
$fileValue=json_decode(fread($fileStream, filesize($linkyValues)));
fclose($fileStream);
echo count($fileValue);//Always 1!
for($i=0;$i<count($fileValue);$i++){
$timeout=$fileValue->item($i)->timeOut;
if(time()>=$timeout){
unset($fileValue[$i]);
}
}
$fileStream = fopen($linkyValues, 'w');
fwrite($fileStream, json_encode($fileValue));
fclose($fileStream);
}
?>
my problem is that count($fileValue) is always 1.
Output of var_dump($fileValue):
object(stdClass)#2 (2) {
["IMD"]=>
object(stdClass)#1 (2) {
["url"]=>
string(21) "http://www.google.com"
["timeOut"]=>
int(1515155361)
}
["cvH"]=>
object(stdClass)#3 (2) {
["url"]=>
string(21) "http://www.google.com"
["timeOut"]=>
int(1515155364)
}
}
it looks like an array to me...

Answer 1

JSON does not support the concept of an associative array, but stores such maps as objects instead.
Your JSON file contains such an object. For PHP this means, that it can either import it as an stdClass ( object ) or as an associatiave array.
This is decided by the json_decode's second parameter, that is either TRUE to read the object as an associative array, or FALSE to read it as an object.
Therefore this will fix your problem:
$fileValue = json_decode(fread($fileStream, filesize($linkyValues)), TRUE);
json_decode documentation
In addition to that, your code has problems with iterating the array. You use $fileValue->item($i) as well as $fileValue[$i], while you have an associative array.
You work with it as if it was an indexed array, while it is an associative array, which means it has keys instead of indices, that identify the values in your array.
The propper way to iterate an associative array is with foreach, like deomstrated belo:
foreach($fileValue as $key => $value) {
if (time() >= $value['timeOut']) {
unset($fileValue[$key]);
}
}
Yet, since you only want to remove specific values, you can use array_filter as well:
$fileValue = array_filter($fileValue, function($value){
return time() < $value['timeOut'];
});
array_filter will then take care of removing the specified fields from your array, so you do not have to unset them manually.

Answer 2

You can use :
count((array)$fileValue);

Answer 3

You're mixing up arrays and objects here.
count() can only be used on arrays, however you can cast an object to array to achieve the same thing.
$fileValue[$i] is a method to access an array, which won't work with your json object.
I see a solution already is to just change your object to an array so I'd like to offer the solution if you wanted to stick with objects.
$linkyValues="./linky.json";
if (file_exists($linkyValues)) {
$fileStream = fopen($linkyValues, 'r');
$fileValue=json_decode($jsonString);
fclose($fileStream);
//Cast the object to an array to get the count, but count isn't really requierd
echo count((array)$fileValue);
//loop through the object
foreach($fileValue as $key=>$fv){
//pull the timeout
$timeout=$fv->timeOut;
//do the check
if(time()>=$timeout){
//remove the timeout from the object
unset($fileValue->$key);
}
}
$fileStream = fopen($linkyValues, 'w');
fwrite($fileStream, json_encode($fileValue));
fclose($fileStream);
}
?>