Create an Array from Json Object - arrays

Question

I have the following JSON structure, calling it from web:
[
{
"Code":"31212",
"Desc":"JOHN",
"DOYDESC":"MADRID",
"Street":"Str41",
"StreetNo":"86"
},
{
"Code":"30214",
"Desc":"GEORGE",
"DOYDESC":"NEW YORK",
"Street":"Str3",
"StreetNo":null
},
{
"Code":"09215",
"Desc":"MARY",
"DOYDESC":"PARIS",
"Street":"Str3",
"StreetNo":"22"
},
{
"Code":"10217",
"Desc":"MEGAN",
"DOYDESC":"ROME",
"Street":"Str4",
"StreetNo":null
}
]
I want the user to give a number in Edit.Text, and then search the values of Code to find if the given value exists.
Is there a way to create an array named Code with the values from the JSON?
For example, to create something like this:
Code = ["31212","30214","09215","10217"]
and then make the search? Or, is there another way to find a specific value of Code from the JSON? I tried this so far:
procedure Tlog_form.Button2Click(Sender: TObject);
var
jso : TJsonObject;
jsv,jsval : TJsonValue;
jsa,jsarr : TJsonArray;
data,str : string;
i,j,user : integer;
jsp : TJsonPair;
arr : array of string;
begin
try
data := GetURLAsString('http://...');
except
on E: exception do
end;
try
jsv := TJSONObject.ParseJSONValue(data);
try
jsa := jsv as TJSONArray;
try
for I := 0 to jsa.Size - 1 do
begin
jso := jsa.Get(i) as TJsonObject;
if jso.ToString = 'Code' then
begin
str := jso.GetValue('Code').ToString;
if Edit1.Text = str then
begin
ShowMessage('found it');
end;
end;
end;
finally
end;
finally
jsv.Free;
end;
except
on E: exception do
end;
end;
When I debug, it doesn't get any error. but it still doesn't work.

Answer 1

You are converting each TJSONObject in the array to a string, and then comparing that to your TEdit text. Which will obviously not match. You need to compare only the Code field of each TJSONObject, which you would be doing if you remove the if jso.ToString = 'Code' then check completely, eg:
procedure Tlog_form.Button2Click(Sender: TObject);
var
jsv : TJSONValue;
jsa : TJSONArray;
jso : TJSONObject;
data, str, code : string;
I : integer;
begin
str := Edit1.Text;
try
data := GetURLAsString('http://...');
jsv := TJSONObject.ParseJSONValue(data);
if jsv <> nil then
try
jsa := jsv as TJSONArray;
for I := 0 to jsa.Size - 1 do
begin
jso := jsa.Get(I) as TJSONObject;
code := jso.GetValue('Code').ToString;
if str = code then
begin
ShowMessage('found it');
end;
end;
finally
jsv.Free;
end;
except
end;
end;

Answer 2

I'm not sure I understand you very well, but if you try TALJsonDocument (https://github.com/Zeus64/alcinoe), you have this function:
Function ALFindJsonNodeByTextChildNodeValue(const JsonNode:TalJsonNode;
Const ChildNodeName: AnsiString;
Const ChildNodeValue : AnsiString;
Const Recurse: Boolean = False): TALJsonNode;