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The TBIJson class enables importing JSON data with automatic handling of nested objects, arrays, and type detection.

​
Quick Start

uses BI.JSON, BI.DataItem;

var
  Data: TDataItem;
  
// Import JSON file
Data := TBIJson.FromFile('data.json');

// Import from text
var
  Json: TBIJson;
Json := TBIJson.Create;
try
  Data := Json.ImportText('{"name":"John","age":30}');
finally
  Json.Free;
end;

​
Key Methods

​
ImportFile

Import a JSON file: 
function ImportFile(const FileName: String): TDataArray;
Example: 
var
  Json: TBIJson;
  DataArray: TDataArray;
  
Json := TBIJson.Create;
try
  DataArray := Json.ImportFile('customers.json');
  Data := TBISource.FromData(DataArray);
finally
  Json.Free;
end;

​
ImportText

Import from JSON string: 
function ImportText(const Text: String): TDataItem;
Example: 
var
  JsonText: String;
  
JsonText := '{' +
  '"products": [' +
    '{"name":"Widget","price":19.99},' +
    '{"name":"Gadget","price":29.99}' +
  ']' +
'}';

Data := Json.ImportText(JsonText);
BIGrid1.Data := Data['products'];

​
Import from TStrings

function Import(const Strings: TStrings): TDataArray;
Example: 
var
  Json: TBIJson;
  
Json := TBIJson.Create;
try
  // For MongoDB format (one object per line)
  Json.Format := TBIJSONFormat.Array;
  DataArray := Json.Import(Memo1.Lines);
finally
  Json.Free;
end;

​
FromFile with Format

class function FromFile(const AFileName: String; 
  const AFormat: TBIJSONFormat): TDataItem;
Example: 
// Normal JSON structure
Data := TBIJson.FromFile('data.json', TBIJSONFormat.Normal);

// Array format (MongoDB style)
Data := TBIJson.FromFile('records.json', TBIJSONFormat.Array);

​
JSON Formats

​
Normal Format

Standard JSON objects and arrays: 
{
  "customers": [
    {
      "id": 1,
      "name": "John Smith",
      "email": "[email protected]"
    },
    {
      "id": 2,
      "name": "Jane Doe",
      "email": "[email protected]"
    }
  ]
}

Json.Format := TBIJSONFormat.Normal; // Default
Data := Json.ImportFile('customers.json');

​
Array Format (MongoDB)

Multiple root objects, one per line: 
{"id":1,"name":"John","city":"NYC"}
{"id":2,"name":"Jane","city":"LA"}
{"id":3,"name":"Bob","city":"Chicago"}

Json.Format := TBIJSONFormat.Array;
Data := Json.ImportFile('restaurants.json');

​
Nested Structures

TeeBI automatically handles nested JSON: 
{
  "order": {
    "id": 12345,
    "customer": {
      "name": "John Smith",
      "email": "[email protected]"
    },
    "items": [
      {"product": "Widget", "quantity": 2},
      {"product": "Gadget", "quantity": 1}
    ]
  }
}

Data := TBIJson.FromFile('order.json');

// Access nested data
CustomerName := Data['order']['customer']['name'].TextData[0];

// Access array items
Items := Data['order']['items'];
BIGrid1.Data := Items;

​
Hierarchical vs Flat Mode

Json.Hierarchical := True;  // Default - preserve structure
Json.Hierarchical := False; // Flatten with master-detail
Hierarchical mode preserves the JSON structure exactly. Flat mode creates master-detail relationships for better grid/query support.

​
Data Type Detection

TBIJson automatically detects:
  • Numbers: Int32, Int64, Double
  • Strings: Text
  • Booleans: Boolean
  • Null values: Missing data markers
  • Arrays: Nested tables
  • Objects: Sub-structures

​
Advanced Examples

​
Import with Progress

var
  Json: TBIJson;
  
Json := TBIJson.Create;
try
  Json.OnProgress := procedure(Sender: TObject; 
                               Percent: Integer; 
                               var Cancel: Boolean)
    begin
      ProgressBar1.Position := Percent;
      Application.ProcessMessages;
    end;
    
  Data := Json.ImportFile('large_data.json');
finally
  Json.Free;
end;

​
Import from Folder

Json.IncludePattern := '*.json';
Json.ExcludePattern := 'temp_*.json';
Data := Json.Import('C:\\JSONData', True); // Recursive

​
Custom Engine

Use a different JSON parser: 
uses BI.JSON.Standard; // or BI.JSON.FPC

TBIJson.EngineClass := TStandardJSON;

var
  Json: TBIJson;
Json := TBIJson.Create;
try
  Data := Json.ImportFile('data.json');
finally
  Json.Free;
end;

​
Export to JSON

Use TBIJSONExport to save data as JSON: 
uses BI.JSON;

var
  Export: TBIJSONExport;
  
Export := TBIJSONExport.Create;
try
  Export.Data := MyData;
  Export.Header := True; // Include metadata
  
  Export.SaveToFile('output.json');
finally
  Export.Free;
end;
Or as a one-liner: 
var
  JsonString: String;
  
JsonString := TBIJSONExport.AsString(MyData, False);

​
File Format Detection

// Check if file is JSON
if TBIJson.Supports('.json') then
  Data := TBIJson.FromFile(FileName);

// Get file filter for dialogs
OpenDialog1.Filter := TBIJson.FileFilter.ToString;
// Returns: 'JSON files|*.json'

​
Common Patterns

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REST API Response

uses System.Net.HttpClient;

var
  Http: THTTPClient;
  Response: IHTTPResponse;
  Json: TBIJson;
  
Http := THTTPClient.Create;
Json := TBIJson.Create;
try
  Response := Http.Get('https://api.example.com/data');
  Data := Json.ImportText(Response.ContentAsString);
finally
  Json.Free;
  Http.Free;
end;

​
Array of Objects

[
  {"id": 1, "name": "Alice"},
  {"id": 2, "name": "Bob"},
  {"id": 3, "name": "Charlie"}
]

Data := TBIJson.FromFile('users.json');
BIGrid1.Data := Data;

​
Common Issues

Check the hierarchical mode:
Json.Hierarchical := True; // or False
Set the correct format:
Json.Format := TBIJSONFormat.Array;
JSON parser detects types automatically. To force a type, convert after import:
Data['amount'].Kind := TDataKind.dkDouble;

​
See Also

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