How to delete value from JSON file with HTTP request and PHP?

Question

Assume a JSON file on a server contains ['one','two','three'].

If an HTML button click event occurs and a variable is set to 'two',
How do you use HTTP request and PHP to delete 'two' from the JSON file if the num variable value matches 'two' in the JSON file?

UPDATE!!! Same value returns after button click

Files (JS & HTML):

$('#button1').click(function() {
  let num = 'two';
  $.ajax({
    type: "POST",
    url: "./update.php",
    data: num
  });
});

<html>

<head>
  <title>Button Writer</title>
</head>

<body>
  <button id="button1" type="button">Write to File</button>



  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

  <script src="./app.js"></script>
</body>

</html>

JSON File: (codes.json)

["one","two","three"]

PHP File (update.php)

<?php
$jsonContents = file_get_contents('./codes.json');//Read here the json file into text
$array = json_decode($jsonContents);

$value = $_POST;

if (($key = array_search($value, $array )) !== false) {
   unset($array [$key]);
}

$jsonString = json_encode($array);
//Here you can save the content of $jsonString into the file again
file_put_contents("./codes.json", $jsonString);

echo $jsonString;
?>

"if this value matches 2" ...what value are you talking about? and what do you want to do with the new altered JSON? put it back in the file? — I wrestled a bear once.
– I wrestled a bear once., Commented Feb 9, 2018 at 20:57
@Iwrestledabearonce. what I mean is to send an HTTP request the value of the variable num to splice out 'two' from the JSON file if there is a match. — claOnline
– claOnline, Commented Feb 9, 2018 at 21:02
@Iwrestledabearonce. Take a look at the JS file. let num = 'two'; on button click event — claOnline
– claOnline, Commented Feb 9, 2018 at 21:09

webketje · Accepted Answer · 2018-02-10 11:09:36Z

1

Then on the server, you can:

$jsonContents = file_get_contents('path/to/file.json'); //Read here the json file into text
$array = json_decode($jsonContents);

$value = $_POST["num"];

if (($key = array_search($value, $array )) !== false) {
   unset($array[$key]);
}

$jsonString = json_encode($array);
//Here you can save the content of $jsonString into the file again
file_put_contents('path/to/file.json', $jsonString);

edited Feb 10, 2018 at 11:09

webketje

11.2k3 gold badges28 silver badges56 bronze badges

answered Feb 9, 2018 at 21:18

Pipe

2,4342 gold badges20 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

webketje Over a year ago

+1 if you change the first line to $jsonContents = file_get_contents('path/to/file.json'); // comment... so PHP doesn't throw a syntax error

claOnline Over a year ago

@Tyblitz I changed the first line and tried to write to file file_put_contents("./codes.json", $jsonString); but values in the JSON file still returns the same. Check the contents of my PHP code above to see if I did something wrong

webketje Over a year ago

@claOnline The code is valid, except you should remove the space between $array [$key]. If it's not that, you probably have a server permission issue (check PHP function chmod), try doing chmod('./code.json', 0755) before you file_put_contents.

claOnline Over a year ago

@Tyblitz. Did everything removed space and added chmod function. It still does not work. Still returns ["one","two","three"] instead of ["one","three"] Anyway, I am testing with XAMPP on windows 10 pc.

webketje Over a year ago

@claOnline Check all other possible points of failure. Does your AJAX call succeed, does PHP respond, etc.? In any case, this falls outside the scope of your original question, and you should probably signal to the community that this answer is correct by accepting it as it does answer the question in the title.

Collectives™ on Stack Overflow

How to delete value from JSON file with HTTP request and PHP?

1 Answer 1

5 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related