Read a specific value from a JSON request using SuperObject

Question

Hello I get the next result in a web API in JSON format:

[
   {
      "$id":"47",
      "CodISO":"BIH",
      "ES":"Bosnia y Herzegovina",
      "EN":"Bosnia and Herzegovina"
   },
   {
      "$id":"48",
      "CodISO":"BLR",
      "ES":"Bielorrusia",
      "EN":"Belarus"
   },
   {
      "$id":"49",
      "CodISO":"BLZ",
      "ES":"Belice",
      "EN":"Belize"
   },
   {
      "$id":"50",
      "CodISO":"BOL",
      "ES":"Bolivia",
      "EN":"Bolivia"
   },
   {
      "$id":"51",
      "CodISO":"BON",
      "ES":"Bonaire",
      "EN":"Bonaire"
   },
   {
      "$id":"52",
      "CodISO":"BOT",
      "ES":"Botsuana",
      "EN":"Botswana"
   },
   {
      "$id":"53",
      "CodISO":"BRA",
      "ES":"Brasil",
      "EN":"Brazil"
   },
   {
      "$id":"54",
      "CodISO":"BRB",
      "ES":"Barbados",
      "EN":"Barbados"
   }
]

Now, I want read the value from item 'ES' where the value of item 'CodISO' = 'BOL' in Delphi SuperObject, I'm not able to find the solution, took all day trying it.

I don't know how iterate with SuperObject elements as I do it with Embarcadero TJSONValue, TJSONObject, TJSONArray. I'm a newbie with SuperObject:

var
  json: ISuperObject;
  Retriever: TIdHTTP;
  Url: string;
  AnsiStr: AnsiString;
begin
  URL := Form1.RestClient1.BaseURL;
  try
    Retriever := TIdHTTP.Create(nil);
    try
      AnsiStr := Retriever.Get(Url);
      json := SO(AnsiStr); 
      { Here code to iterate with json elements in SuperObject.......
      .
      .
      .
      .
      }             
    finally
      Retriever.Free;
    end;
  except
    on E: Exception do
      ShowMessage(E.ClassName + ': ' + E.Message);
  end;
End;

"I'm not able to find the solution, took all day trying it" - what exactly did you try? Please show your code. This should not have taken more than a few minutes to solve if you actually look at SuperObject's available API. JSON does not have anything like XPath for XML, so you have to iterate the items manually. Starting at the root array, you loop through the array's items one at a time reading their `CodISO` and `ES` fields as needed, then break the loop when you find a match. Simple as that. — Remy Lebeau, Nov 23 '14 at 23:38
Did you have a look at the [readme.html](https://superobject.googlecode.com/git/readme.html) of superobject? That is the intention of a readme file, you should read to get more information — Sir Rufo, Nov 24 '14 at 00:28

score 1 · Accepted Answer · edited Sep 01 '21 at 10:52

As Sir Rufo said, you need to read the SuperObject documentation.

Try something like this:

var
  JsonArr, JsonObj: ISuperObject;
  Retriever: TIdHTTP;
  Url, JsonStr, ES: string;
  I: Integer;
begin
  URL := Form1.RestClient1.BaseURL;
  try
    Retriever := TIdHTTP.Create(nil);
    try
      JsonStr := Retriever.Get(Url);
    finally
      Retriever.Free;
    end;
    JsonArr := SO(JsonStr).AsArray; 
    for I := 0 to JsonArr.Length-1 do
    begin
      JsonObj := JsonArr.O[I];
      if JsonObj.S['CodISO'] = 'BOL' then
      begin
        ES := JsonObj.S['ES'];
        Break;
      end;
    end;
  except
    on E: Exception do
      ShowMessage(E.ClassName + ': ' + E.Message);
  end;
end;

Read a specific value from a JSON request using SuperObject

1 Answers1