writing all files in directory to json - php

Question

I made simple text editor and now working on image upload and image manager. I have set up manager to read .json file with all images and it works ok. The problem is for php script to actually write newly added images to that json.
$file = "images.json";
$arr_data = array();
foreach(glob('/uploads/*') as $image) {
$arr_data = array(
'link' => $image,
'tag' => 'images',
);
}
$jsondata = file_get_contents($file);
$arr_data = json_decode($jsondata, true);
array_push($arr_data,$jsondata);
$jsondata = json_encode($arr_data, JSON_PRETTY_PRINT);
file_put_contents($file, $jsondata));
I am getting
Warning: array_push() expects parameter 1 to be array
even tho array data is provided. How to solve this?

Answer 1

If you are starting with an empty file i.e. images.json then the first time you run these 2 lines
$jsondata = file_get_contents($file);
$arr_data = json_decode($jsondata, true);
the second line will change $arr_data into a boolean probably. As json_decode() will fail to convert nothing into an array.
So add this to initialize the file for use
<?php
$file = "images.json";
file_put_contents($file, '[]'); // init the file
You are also reusing the $arr_data variable so amend this also and you are overwriting the new array as well
$file = "images.json";
file_put_contents($file, '[]'); // init the file
$arr_data = array();
foreach(glob('/uploads/*') as $image) {
// amended to not reuse $arr_data
// ameded to not overwrite the array as you build it
$new_arr[] = array( 'link' => $image, 'tag' => 'images');
}
$jsondata = file_get_contents($file);
$arr_data = json_decode($jsondata, true);
array_push($arr_data,$new_arr);
$jsondata = json_encode($arr_data, JSON_PRETTY_PRINT);
file_put_contents($file, $jsondata));