Add to a JSON object, with PHP

I’d like to increment a JSON object with a new given one but I can’t do it. I have the following JSON:

{ "field_name":{ "type":"text", "visual_name":"Field Name", "required": true } }

The user will create more fields and I’d like to insert in the original JSON the new field that comes in this format:

"field_name2":{ "type":"select", "visual_name":"Field Name 2", "required": true, "options":{"opt1":"yes","opt2":"no"} }

Answer

Looks like you’re trying to add new elements to the root JSON object, in which case you simply need to:

1. Decode the JSON objects into PHP arrays.
2. Merge the arrays into one.
3. Encode the merged array back into JSON.

$field1 = '{"field_name":{"type":"text", "visual_name":"Field Name", "required":true}}';
$field2 = '{"field_name2":{"type":"select", "visual_name":"Field Name 2", "required":true, "options":{"opt1":"yes", "opt2":"no"}}}';

$arr = array_merge(json_decode($json1, true), json_decode($json2, true));
$json = json_encode($arr);

The final $json object will be:

{
    "field_name": {
        "type": "text",
        "visual_name": "Field Name",
        "required": true
    },
    "field_name2": {
        "type": "select",
        "visual_name": "Field Name 2",
        "required": true,
        "options": {
            "opt1": "yes",
            "opt2": "no"
        }
    }
}

If you want to add the fields into a JSON array, rather than an object, you can do this instead:

$arr = [json_decode($json1, true), json_decode($json2, true)];

Which results in:

[
    {
        "field_name": {
            "type": "text",
            "visual_name": "Field Name",
            "required": true
        }
    },
    {
        "field_name2": {
            "type": "select",
            "visual_name": "Field Name 2",
            "required": true,
            "options": {
                "opt1": "yes",
                "opt2": "no"
            }
        }
    }
]

---

Note

If you try to add your original second field as you have given it in your question, it won’t work because it’s not a fully formatted JSON string. You must ensure it has the outer pair of curly braces.

Incorrect:

"field_name2":{"type":"select", "visual_name": ...}

Correct:

{"field_name2":{"type":"select", "visual_name": ...}}