翻译 PHP REST API 中的响应和请求

Question

I am still struggling with a logic how to translate correctly the response and the request for my PHP REST API. I have following array which I get from the REST API

[{
  "id": "49557a36-028b-40c6-b2d8-8095468af130",
  "startDate": "2020-04-15T06:00:00Z",
  "endDate": "2020-04-15T10:00:00Z",
  "bookedOn": "0001-01-01T00:00:00",
  "doctorNotes": "",
  "firstVisit": true,
  "visitReasonID": "",
  "patient": {
    "firstName": "",
    "lastName": "",
    "birthday": "0001-01-01T00:00:00",
    "gender": "x",
    "street": "",
    "postboxNumber": "",
    "city": "",
    "zip": "",
    "country": "",
    "email": "",
    "telephone": "",
    "info": ""
  }]

on the other hand I also have some data which I send to the REST API and it goes like this

array(8) {
  ["GUID"]=>
  NULL
  ["datumzeit_from"]=>
  string(19) "2020-03-13 13:30:00"
  ["datumzeit_till"]=>
  string(16) "2020/03/13 17:00"
  ["titel"]=>
  string(2) "61"
  ["beschreibung"]=>
  string(4) "okay"
  ["firstVisit"]=>
  bool(true)
  ["patient"]=>
  array(1) {
    [0]=>
    array(11) {
      ["vorname"]=>
      string(4) "John"
      ["nachname"]=>
      string(7) "Daniels"
      ["geburtsdatum"]=>
      string(10) "1970-01-01"
      ["titel"]=>
      string(4) "Herr"
      ["strasse"]=>
      string(15) "Danielstraße 3"
      ["ort"]=>
      string(6) "Conan"
      ["plz"]=>
      string(5) "93085"
      ["land"]=>
      string(2) "DE"
      ["email"]=>
      string(1) "1"
      ["telnr"]=>
      string(10) "0835597839"
      ["referenz"]=>
      string(3) "nothing"
    }
  }
  ["last_updated"]=>
  string(19) "2020-03-09 17:08:23"
}

for proper translation I created an exchange Array which goes like this:

<?php $exchangeArray = array( 
    "id" => "GUID",
    "startDate" => "datumzeit_from",
    "endDate" => "datumzeit_till", 
    "bookedOn" => "last_updated", 
    "doctorNotes" => "beschreibung",
    "firstVisit" => "firstVisit",
    //"visitReasonName" => "titel",
    "visitReasonID" => "visitreason_nr",
    "patient" => array(
        "firstName" => "vorname",
        "lastName" => "nachname",
        "birthday" => "geburtsdatum",
        "gender" => "titel", //anders
        "street" => "strasse",
        //"postboxnumber" => "",
        "city" => "ort", // ort id
        "zip" => "plz",
        "country" => "land", 
        "email" => "email",
        "telephone" => "telnr",
        "info" => "referenz"),
); ?>

now to my main problem, always when I send or want to receive the data, I always want to translate it between my database and REST API and I do exactly the following $result = translate(json_decode($data, "IN"); //either json_decode+IN or encode+OUT to call the result I either put some data and send it out or decode and receive it. So I basically want to change keys and preserve the values, so here's the bottleneck

function sortVars($var, $iterKey, $iterVal, $i, $IN = TRUE){ //the main logic is here and also the issue in the algorithm, it sorts out the variables
    if(is_array($var)){
        foreach($iterVal as $x=>$y){
            if($IN == TRUE){
                if(isset($var[$x])) $transformed[$i][$iterKey][$var[$x]] = $y;
            } else if(isset($var[$y])) $transformed[$i][$iterKey][$var[$y]] = $x;   
        }
    } else $transformed[$i][$var] = $iterVal;
return $transformed;
}   
function transSort($data, $stat, $i=0){ //that one sorts out the whole array
    global $exchangeArray;
    if($stat == "IN"){
        foreach($data as $kay=>$val){
            if(isset($exchangeArray[$kay])){
                $transformed[] = sortVars($exchangeArray[$kay], $kay, $val, $i);
            }       
        }
    } elseif($stat == "OUT"){
        foreach($exchangeArray as $kay=>$val){
            if(!is_array($val)){
                if(isset($data[$val])) $transformed = sortVars($data[$val], $val, $kay, $i, FALSE);
            } else{ //for strange reason its array with 0 in the beginning
                if(isset($data[0][$val])) $transformed = sortVars($data[$val], $val, $kay, $i, FALSE);
            }
        }
    }
    $i++;
    return $transformed;
}
function translate($data, $stat){ //translate response
    $i=0;
    if(isset($data[1])){ //if its array
        foreach($data as $key){
            $result = transSort($key, $stat, $i++);
        }
    } else $result = transSort($data, $stat);

    return $result;
}

It loops over arrays and depending on $stat translates them either to request or response, but it doesn't translate correctly and still has many issues, I had just one function before and $stat=IN worked perfectly fine but once I created more functions to have less code it started to have issues and also $stat=OUT has some logic problems regarding the correct translation, does someone have an idea what's the main issue in the following code?

Answer 1

I often run into cases where I need to convert something from model A to model B (regardless of translation).

I find that it's almost always easier to not create a configuration + system for automatically translating. Even though it's a bit more typing, just creating a function for each case has some advantages:

1. Easier to see whats going on
2. Simpler code
3. Not every conversion is easy to express. This might make your 'conversion system' to grow in complexity over time and this can get very painful. The configuration might at some point rival if you just wrote the code. As you can see, it's already quite complex and hard to debug.

So if this was me, I would write small conversion functions for each case:

function toGerman($input) {

  return [
    "datumzeit_from" => $input['startDate'],
    // every other property
  ];

}

I noticed that writing a function instead of a configuration + mapping system goes against the nature of a lot of devs, but it's easy to see how much easier and flexible this can be. It's just PHP. You can use loops and deal with weird edge cases, Instead. you wrote a little transpiler.

Unfortunately you might not consider this a real answer to your question, if so I'm happy to delete this answer.

Answer 2

I think there is a slightly simpler way

1) Create a function to flip the German => Eng to Eng => German

function array_flip_recursive($array) {

    $out = [];

    foreach ($array as $k => $v) {

        if (is_array($v)) {

            $out[$k] = array_flip_recursive($v);

        } else {

            $out[$v] = $k;

        }

    }

    return $out;

}

2) Replace the keys with the translated version

function translate($data, $dictionary, $flip = false) {

    if ($flip) $dictionary = array_flip_recursive($dictionary);

    $out = [];

    foreach ($data as $k => $v) {

        if (is_array($v)) {

            $out[$k] = translate($v, $dictionary[$k], $flip);

        } else {

            $out[$dictionary[$k]] = $v;

        }

    }

    return $out;

}

This function would take either your database output or the api output and the $exchangeArray from your earlier code. The $flip variable is in case you're converting German back to English.

Note you will need to json_decode($api_output, true) your API output to convert it to an associative array. The example you gave was an array of data, so you'd then need to loop over it:

3) Process your data

//From the API
foreach(json_decode($api_output, true) as $api_data) {

    $myData[] = translate($api_data, $exchangeArray);

}

print_r($myData);

//From your database
foreach($database_output as $database_data) {

     $myData[] = translate($database_data, $exchangeArray, true);

}

print_r($myData);