merge json from directory to one file

[Jeisson]

Hello

I have several json files in one directory. i would like to merge them in to one.

I did something like this

<?php
foreach (glob("../json/*.json") as $filename) {
    echo basename($filename) . "\n";
}
$res1 = file_get_contents($filename);
echo $res1;
?>

But it echoes only the last (the first echo is to view all files which is not important here)

Then I tried many versions of foreach inside foreach with no success. Like this:

<?php
foreach (glob("../json/*.json") as $filename) {

foreach (file_get_contents($filename) as $a) {
  }
}
echo $a;
?>

So I appreciate a little help here, thank you.

[Jacques1]

If you want to do something with each $filename, you have to do it inside the loop. Doing it after the loop only gets you the last filename as a leftover.

<?php

$complete_json = '';
foreach (glob(__DIR__.'/../json/*.json') as $json_path)
{
    $complete_json .= file_get_contents($json_path);
}

echo $complete_json;

Note that a JSON document has a specific structure (it must be either an array or an object), so you probably can't just concatenate all individual files. You'll need to wrap them in a common structure.

Edited February 25, 2016 by Jacques1

[Jeisson]

thank you I will continue from here. The json files have all same structure so I thought I could merge them to one.

 

But if that will not work I will try to get a specific key from each files directly. Maybe something like that would be better anyway.

[Jacques1]

You can merge JSON documents, but you can't just concatenate them. If all documents have an object as their toplevel structure, you need to put the key/value pairs into a common object, possibly resolving key conflicts. If all documents are arrays, you can concatenate the individual elements. In both cases, array_merge() should be useful.

 

But if you already have a better approach, that's of course preferrable.

[Jeisson]

I don't yet have any better approach I'm just thinking out loud. I will need to try and test. this was first step.

 

Are you suggesting it would be safe way to decode everything then array_merge and encode this to json?

[Jacques1]

If you're dealing with JSON arrays, yes. In case of objects, you need to be careful with conflicting keys. It might make more sense to keep each object in a separate “namespace”. For example,

{
    "x": 1,
    "y": 3
}

and

{
    "x": 2
}

would become

{
    "a-meaningful-name-for-the-first-dataset" : {
        "x": 1,
        "y": 3
    },
    "a-meaningful-name-for-the-second-dataset" : {
        "x": 2
    }
}

But I don't know your data, so this is a decision you'll have to make.

[Jeisson]

yeah I will see. My json files are not ready yet. So I will work on them when I have the code that does something with them. Iḿ just such a noob.

May I ask why first code works

json_decode($complete_json,true);
var_dump($complete_json);

while this not.

$content = json_decode($complete_json,true);
var_dump($content);

I just don see the logic always

[Jacques1]

The first code fragment doesn't do anything (useful). It decodes $complete_json, throws away the result and then dumps the original JSON-encoded data. The second fragment attempts to actually display the decoded content.

 

Are you sure $complete_json is valid JSON? Like I already said, concatening individual JSON documents doesn't work, it was just a demonstration of loop logic.

[Jeisson]

Ok now I realize. I thought in my case they would be valid but that is not the case.
Need to re-think the whole thing now. Something like decoding each file and then getting what I am lookin for and store that as new json. Whole merging and concatening I think I do not need..