How to access multidimensional JSON array in php

Question

I am trying to build a web based file manager where I can view, create, edit, and delete folders and files. I need a data structure for storing the information about the files folders and subfolders.

I was trying JSON, but the problem is that there can be any number of subfolders inside subfolders which will come dynamically.

I wrote by hand a JSON test file, which the link is given below

{
  "home": {
    "file1": {
      "type": "file",
      "name": "test",
      "ext": "pdf",
      "date": "12/03/2015"
    },
    "file2": {
      "type": "file",
      "name": "test",
      "ext": "doc",
      "date": "31/01/2010"
    },
    "folder1": {
      "type": "folder",
      "name": "folder1",
      "date": "11/01/2010",
      "in": {
        "file": {
          "type": "file",
          "name": "test3",
          "ext": "pdf",
          "date": "23/01/2017"
        },
        "folder2": {
          "type": "folder",
          "name": "folder2",
          "date": "22/03/2011",
          "in": {
            "file4": {
              "type": "file",
              "name": "test3",
              "ext": "pdf",
              "date": "23/01/2017"
            }
          }
        },
        "folder4": {
          "type": "folder",
          "name": "folder4",
          "date": "11/09/2009",
          "in": {
            "file5": {
              "type": "file:",
              "name": "file5",
              "date": "11/09/2011"
            }
          }
        }
      }
    },
    "folder7": {
      "type": "folder",
      "name": "folder7",
      "date": "23/08/2015",
      "in": {
        "file7": {
          "type": "file",
          "name": "file7",
          "date": "11/01/2016"
        }
      }
    }
  }
}

There will be a dynamic generation of folders and subfolders which needed to be updated in the JSON file.

How can I access all the data from the JSON file after encoding into a variable in PHP or JavaScript, and update the file with new data as well?

Thank you

Lucas Meine · Answer 1 · 2017-05-27T03:29:45.397

0

Read the file using file_open()

Parse the json using json_decode

Do whatever you want with your arrays

encode the json again with json_encode

write it to your file again with fwrite()

Your code should look like this:

<?php
 $json = fread($myfile,filesize("json.txt"));
 $json = json_decode($json);
 //json is now an array, do whatever you want with it
 $json = json_encode($json);
 fwrite(file,json);

edited May 27 '17 at 03:29

answered May 27 '17 at 03:26

Lucas Meine

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How can I access all the dimensions in json using php? – Ep Sooraj May 27 '17 at 03:28
Once you use json_decode, you can work with it as an array – Lucas Meine May 27 '17 at 03:31
It would look like something like this: $json['home']['file1']['type'] – Lucas Meine May 27 '17 at 03:32
How to access them if I don't know what all data is inside it and how many dimensions it went in? home, file1, type etc are dynamically created. How to access if I cannot know the variables? – Ep Sooraj May 27 '17 at 03:32
then you can just iterate the arrays using foreach, so you can access the individual indexes and keys – Lucas Meine May 27 '17 at 03:33
sure: foreach($json as $key=>$value) { echo $value; } – Lucas Meine May 27 '17 at 03:34
Thank you. I will try that. :) – Ep Sooraj May 27 '17 at 03:36
One problem I am facing now is, using above code I can only go through the first layer. The file will have layers inside layers. And the depth is also unknown. How can I access every layer dynamically [ I cannot know any values inside the file] – Ep Sooraj May 27 '17 at 05:22
you can check if the value is an array, and if it is, iterate through it – Lucas Meine May 27 '17 at 05:25
check out this question for further reference on this subject: https://stackoverflow.com/questions/3684463/php-foreach-with-nested-array – Lucas Meine May 27 '17 at 05:26

score 0 · Answer 2 · answered May 27 '17 at 03:27

The below snippet should work, it basically does a json_decode($str, true) of the JSON string :

$str = '{
    "type": "folder",
    "name": "folder1",
    "date": "11/01/2010",
    "in": {
        "file": {
            "type": "file",
            "name": "test3",
            "ext": "pdf",
            "date": "23/01/2017"
        },
        "folder2": {
            "type": "folder",
            "name": "folder2",
            "date": "22/03/2011",
            "in": {
                "file4": {
                    "type": "file",
                    "name": "test3",
                    "ext": "pdf",
                    "date": "23/01/2017"
                }
            }
        },
        "folder4": {
            "type": "folder",
            "name": "folder4",
            "date": "11/09/2009",
            "in": {
                "file5": {
                    "type": "file:",
                    "name": "file5",
                    "date": "11/09/2011"
                }
            }
        }
    }
}';


var_dump(json_decode($str, true));

After encoding how can I access the data from the encoded variable? — Ep Sooraj, May 27 '17 at 03:29
Basically, it would be something like `$array['in']['folder4']['in']['file5']['type']` — Gayan Hewa, May 27 '17 at 03:31

score 0 · Answer 3 · answered May 27 '17 at 03:43

0

Your code should look like this:

<?php
 $json = file_get_contents('json.txt'); // read the file contains JSON code
 $array = json_decode($json); // convert json to normal php array

 //json is now a normal php array, do whatever you want with it

 echo '<pre>';
 print_r($array);
 echo '</pre>';

 $json = json_encode($array);
 file_put_contents('json.txt');

answered May 27 '17 at 03:43

Thanx for the reply I'll try this – Ep Sooraj May 27 '17 at 05:03

How to access multidimensional JSON array in php

3 Answers3