Delphi REST Client API

A Delphi REST client API to consume REST services written in any programming language.

The API was tested in Delphi 7, XE, XE2, XE3, XE4 and XE7. It is also compatible with Mac OSX and iOS.

Connection Layer

There are a IHttpConnection interface to abstract the real Http conection. This interface currently have two implementations, using Indy 10, WinHTTP and WinInet.

Indy 9 does not handles HTTP response codes correctly, then if you are using Delphi 7, you must update your indy library to version 10 or use WinHttp (recommended). To disable indy support comment the compiler directive {.$DEFINE USE_INDY} in DelphiRest.inc file.

Serialization/Desserialization

The objects are transmitted in JSON format. To function properly, the object must be declared as follows, with public fields.

TPerson = class(TObject)
public
  (* Reflect the server side object field names, for Java must be case-sensitive *)
  id: Integer;
  name: String;
  email: String;

  (* Static constructor *)
  class function NewFrom(Id: Integer; Name, EMail: String): TPerson;
end;

See more details about serialization here: Serialization

Samples

Note that all code below assume you have installed the component in your IDE and dropped the RestClient component on a form or data module, but of course you can also create the component directly in your code.

GET

var
  vList : TList<TPerson>;
begin
  vList := RestClient.Resource('http://localhost:8080/java-rest-server/rest/persons')
                     .Accept(RestUtils.MediaType_Json)
                     .Get<TList<TPerson>>();

GET ONE

var
  vPerson : TPerson;
begin
  vPerson := RestClient.Resource('http://localhost:8080/java-rest-server/rest/person/1')
                 .Accept(RestUtils.MediaType_Json)
                 .Get<TPerson>();

POST

var
  vPerson : TPerson;
begin
  vPerson := TPerson.NewFrom(123, 'Fabricio', 'fabricio.colombo.mva@gmail.com');
  RestClient.Resource('http://localhost:8080/java-rest-server/rest/person')
            .Accept(RestUtils.MediaType_Json)
            .ContentType(RestUtils.MediaType_Json)
            .Post<TPerson>(vPerson);

PUT

var
  vPerson : TPerson;
begin
  vPerson := //Load person
  vPerson.Email := 'new@email.com';
  RestClient.Resource('http://localhost:8080/java-rest-server/rest/person')
            .Accept(RestUtils.MediaType_Json)
            .ContentType(RestUtils.MediaType_Json)
            .Put<TPerson>(vPerson);

DELETE

var
  vPerson : TPerson;
begin
  vPerson := //Load person
  RestClient.Resource('http://localhost:8080/java-rest-server/rest/person')
            .Accept(RestUtils.MediaType_Json)
            .ContentType(RestUtils.MediaType_Json)
            .Delete(vPerson);

GET AS DATASET

The fields need be predefined.

var
  vDataSet: TClientDataSet;
begin
  vDataSet := TClientDataSet.Create(nil);
  try
    TDataSetUtils.CreateField(vDataSet, ftInteger, 'id');
    TDataSetUtils.CreateField(vDataSet, ftString, 'name', 100);
    TDataSetUtils.CreateField(vDataSet, ftString, 'email', 100);
    vDataSet.CreateDataSet;

   RestClient.Resource(CONTEXT_PATH + 'persons')
              .Accept(RestUtils.MediaType_Json)
              .GetAsDataSet(vDataSet);
  finally
    vDataSet.Free;
  end;

GET AS DYNAMIC DATASET

The fields are created dynamically according to the returned content.

var
  vDataSet: TDataSet;
begin
  vDataSet := RestClient.Resource(CONTEXT_PATH + 'persons')
                        .Accept(RestUtils.MediaType_Json)
                        .GetAsDataSet();
  try
    //Do something
  finally
    vDataSet.Free;
  end;

Authentication

RestClient supports HTTP Basic authentication. You can set credentials using the SetCredentials method before making the first request:

RestClient.SetCredentials('username', 'password');

You can set it once and it will be used for every request.

Java Rest Server

The java project is only for test purpose and has built using Maven and Jersey, so it's needed have installed the JRE 6+ (Java Runtime Environment) and Maven 2 to build and run the application. The Maven bin directory must be included in Windows Path environment variable.

After install Java and Maven just run 'start-java-server.bat' to start the application and 'stop-java-server.bat' to shut down them.

When 'start-java-server.bat' is first run maven dependencies will be downloaded, and it may take a while.

License

The Delphi REST client API is released under version 2.0 of the Apache License.

pedrolopix / delphi-rest-client-api