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.