Formatting JSON formatted text file in PHP - php

Question

So I got a HTML page with a button. When I click the button, a separate javascript file sends a GET request to my PHP file, expecting a JSON object in return. My PHP reads a JSON formatted text file and should convert it into a JSONObject and echo it out for my javascipt. I had some code working before, but it doesn't seem to do it anymore since I changed to a Ajax aproach instead of having everything in the same file. This is my code:
readLog.php
<?php
class test{
function clean($string){
return json_decode(rtrim(trim($string),','),true);
}
function getLog(){
header('Content-Type: application/json');
$logLines = file('../../../home/shares/flower_hum/humid.log');
$entries = array_map("clean",$logLines);
$finalOutput = ['log' => $entries];
echo json_encode($logLines);
}
}
?>
My humid.log file looks like this:
{"date":"26/09/2016", "time":"22:40:46","temp":"16.0", "humidity":"71.0" }
{"date":"26/09/2016", "time":"23:10:47","temp":"16.0", "humidity":"71.0" }
Now If I press my button, this is the response I get checking the console in my web browser:
Response:
["{\"date\":\"26\/09\/2016\", \"time\":\"22:40:46\",\"temp\":\"16.0\", \"humidity\":\"71.0\" }{\"date\":\"26\/09\/2016\", \"time\":\"23:10:47\",\"temp\":\"16.0\", \"humidity\":\"71.0\" }\n"]
JSON:
"{"date":"26/09/2016", "time":"22:40:46","temp":"16.0", "humidity":"71.0" }{"date":"26/09/2016", "time":"23:10:47","temp":"16.0", "humidity":"71.0" }\n"
obviously something is wrong with the formatting, but I don't know what. As I said, this code worked just fine when I had my php and HTML in the same file.
EDIT:
I have also tried formatting the JSON with something like this, but it just prints the brackets:
function getLog(){
$text = file('../../../home/shares/flower_hum/humid.log');
$textRemoved ="["; //Add opening bracket.
$textRemoved .= substr($text, 0, strlen($text)-1); (Remove last comma)
$textRemoved .="]";//Add closing bracket
$json = json_encode($textRemoved);
echo $json;
}

Answer 1

So I managed to solve it myself. Basicly The formatting of the textfile was wrong and as some commentors said, I don't need to encode it if I am doing it myself. What I ended up doing was in my application that generates the log file to add comma after each row. Then in my PHP I added brackets and removed the last comma.
function getLog(){
header('Content-Type: application/json');
$file = file_get_contents('../../../home/shares/flower_hum/humid.log');
$lengthOfFile = strlen($file)-2;
$subFile = substr($file, 0, $lengthOfFile);
$res ="[";
$res .= $subFile;
$res .="]";
echo $res;
}

Answer 2

You can't just jam two+ JSON strings togther. It's JSON, which means it HAS to be syntactically correct Javascript CODE. If you want to join two json strings together, you HAVE to decode them to a native data structure, join those structures together, then re-encode the new merged structure:
$temp1 = json_decode('{"foo":"bar"}', true);
$temp2 = json_decode('{"baz":"qux"}', true);
$new = array_merge($temp1, $temp2);
echo json_encode($new);
which will produce:
{"foo":"bar","baz":"qux"}
and remain valid JSON/Javascript.
Why? Consider that bare integers are valid json:
json_encode(42) -> 42
json_encode(123) -> 123
If you have two json-encoded integers and jam together, you get a "new" integer:
42123
and on the receiving end, you'll be going "Ok, so where is the split between the two", because 4 and 2123 are just as valid as possible original values as 4212 and 3.
Sending the two integers as distinct and SEPARATABLE values would require an array:
[42,123]