how to use JSON.stringify and json_decode() properly
PhpJavascriptArraysJsonStringifyPhp Problem Overview
Im trying to pass a mulitidimensional Javascript array to another page on my site by:
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using JSON.stringify on the array
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assigning the resultant value to an input field
-
posting that field to the second page
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using json_decode on the posted value
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then var_dump to test
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(echo'ing the posted variable directly just to see if it came through at all)
Javascript on page one:
var JSONstr = JSON.stringify(fullInfoArray);
document.getElementById('JSONfullInfoArray').value= JSONstr;
php on page two:
$data = json_decode($_POST["JSONfullInfoArray"]);
var_dump($data);
echo($_POST["JSONfullInfoArray"]);
The echo works fine but the var_dump returns NULL
What have I done wrong?
This got me fixed up:
$postedData = $_POST["JSONfullInfoArray"];
$tempData = str_replace("\\", "",$postedData);
$cleanData = json_decode($tempData);
var_dump($cleanData);
Im not sure why but the post was coming through with a bunch of "" characters separating each variable in the string
Figured it out using json_last_error() as sugested by Bart which returned JSON_ERROR_SYNTAX
Php Solutions
Solution 1 - Php
When you save some data using JSON.stringify() and then need to read that in php. The following code worked for me.
json_decode( html_entity_decode( stripslashes ($jsonString ) ) );
Thanks to @Thisguyhastwothumbs
Solution 2 - Php
When you use JSON stringify then use html_entity_decode first before json_decode.
$tempData = html_entity_decode($tempData);
$cleanData = json_decode($tempData);
Solution 3 - Php
You'll need to check the contents of $_POST["JSONfullInfoArray"]. If something doesn't parse json_decode will just return null. This isn't very helpful so when null is returned you should check json_last_error() to get more info on what went wrong.
Solution 4 - Php
None of the other answers worked in my case, most likely because the JSON array contained special characters. What fixed it for me:
Javascript (added encodeURIComponent)
var JSONstr = encodeURIComponent(JSON.stringify(fullInfoArray));
document.getElementById('JSONfullInfoArray').value = JSONstr;
PHP (unchanged from the question)
$data = json_decode($_POST["JSONfullInfoArray"]);
var_dump($data);
echo($_POST["JSONfullInfoArray"]);
Both echo and var_dump have been verified to work fine on a sample of more than 2000 user-entered datasets that included a URL field and a long text field, and that were returning NULL on var_dump for a subset that included URLs with the characters ?&#.
Solution 5 - Php
stripslashes(htmlspecialchars(JSON_DATA))
Solution 6 - Php
jsonText = $_REQUEST['myJSON'];
$decodedText = html_entity_decode($jsonText);
$myArray = json_decode($decodedText, true);`
Solution 7 - Php
I don't how this works, but it worked.
$post_data = json_decode(json_encode($_POST['request_key']));