如何使用php更新（覆盖）json文件

Question

[
  {
     "id"  : 1,
    "name"  : "levin",
    "description" : "some desc",
    "size"  : "100KG",
     "actions" : {
                 "walking" : true,
                  "eating" : true
                  }
  },
  {
    "id"  : 2,
    "name"  : "clara",
    "description" : "some desc",
    "size"  : "2000KG",
     "actions" : {
                 "walking" : false,
                  "eating" : true
                  }

  }
]

This is my person.json file. I like to update(overwrite) existing values. Am not found any useful questions regarding this.

i have a name "levin" i like to overwrite it to empty or "---". But its should only based through "id" .Following is my php code but its not working :(

public function api_put()
    {
         //print($this->put('id')); am getting here 2 value from other page 
        //print($this->put('action'));.

        if($this->put('action') == "remove"){
            $file = json_decode(file_get_contents("assets/json/person.json"));
            $new_val = array();
            $i = 0 ;
            foreach ($file as $key => $value) {
                if((string)$value->id == $this->put('id')) {
                    $data[] = (string)$value->name="--";(string)$value->description="--";
                    $new_val[$i] =  $data;
                    $i++;
                }

            }
            file_put_contents('assets/json/person.json', json_encode($new_val));
            $message = array('id' => $this->put('id'), 'message' => 'Successfully updated!!');

            $this->response($message, 200); 
        }
    }

How can i overwrite a json value depend upon a particular id and with out change all other id data. am using codeigniter REST api. thanks in advance

Answer 1

A couple of things.

1. You don't need a $new_val array, you can just edit these resources in place.
2. PHP is weakly typed , so doing (string)$value->id == $this->put('id') is not necessary. The PHP engine will do this conversion for you.
3. Casting on the left side of the equal sign does nothing. (string)$value->description="--"; That statement has no effect.
4. This is poor form, in any programming language ... (string)$value->name="--";(string)$value->description="--"; Two statements doing two operations should be on two different lines.
5. General concept, your code should be easy to read. Space it out a little bit, let it breath. When you come back to your code years later you'll be glad that you did.

---

public function api_put()
{
    if ($this->put('action') == 'remove')
    {
        $file = json_decode(file_get_contents('assets/json/person.json'));

        foreach ($file as $key => $value)
        {
            if ($value->id == $this->put('id'))
            {
                $value->name = '--';
                $value->description = '--';
            }
        }

        file_put_contents('assets/json/person.json', json_encode($file));

        $message = array('id' => $this->put('id'), 'message' => 'Successfully updated!!');

        $this->response($message, 200);
    }
}

There, isn't that much nicer?

Answer 2

I think you must need to loop like this to store all details

foreach ($file as $key => $value) {
    if((string)$value->id == $this->put('id')) {
        $value->name="--";(string)$value->description="--";
    }
        $new_val[$i] =  $value;
    $i++;

}