TdjWebComponent Class Reference

A base class which can be subclassed to create a HTTP component for a Web site. More...

Inheritance diagram for TdjWebComponent:

Public Member Functions
	TdjWebComponent ()
	~TdjWebComponent ()
TIdHTTPSession	GetSession (TdjServerContext Context, TdjRequest Request, TdjResponse Response, const Boolean Create=True)
	Get or create a HTTP session.
IWebComponentConfig	GetWebComponentConfig ()
	Returns a IWebComponentConfig object, which contains initialization parameters for this component.
	Init ()
	A convenience method which can be overridden so that there is no need to call inherited Init(config).
	Init (const IWebComponentConfig Config)
	Called by the container on startup.
	Service (TdjServerContext Context, TdjRequest Request, TdjResponse Response)
	Handle a HTTP request.

Public Attributes
IWebComponentConfig	Config

Protected Member Functions
	OnDelete (TdjRequest Request, TdjResponse Response)
	Called by the server to handle a DELETE request.
	OnGet (TdjRequest Request, TdjResponse Response)
	Called by the server (via the service method) to allow a component to handle a GET request.
TDateTime	OnGetLastModified (TdjRequest Request)
	Returns the time the WebComponent object was last modified.
	OnHead (TdjRequest Request, TdjResponse Response)
	Called by the server (via the service method) to allow a component to handle a HEAD request.
	OnOptions (TdjRequest Request, TdjResponse Response)
	Called by the server (via the service method) to allow a component to handle a OPTIONS request.
	OnPatch (TdjRequest Request, TdjResponse Response)
	Called by the server to handle a PATCH request.
	OnPost (TdjRequest Request, TdjResponse Response)
	Called by the server to handle a POST request.
	OnPut (TdjRequest Request, TdjResponse Response)
	Called by the server to handle a PUT request.
	OnTrace (TdjRequest Request, TdjResponse Response)
	Called by the server to handle a TRACE request.

Detailed Description

A base class which can be subclassed to create a HTTP component for a Web site.

A subclass of TdjWebComponent must override at least one method, usually one of these:

• OnGet, if the web component supports HTTP GET requests
• OnPost, for HTTP POST requests
• OnPut, for HTTP PUT requests
• OnDelete, for HTTP DELETE requests

Constructor & Destructor Documentation

TdjWebComponent()

TdjWebComponent::TdjWebComponent

(

)

References TdjWebComponent().

Referenced by TdjWebComponent(), ~TdjWebComponent(), OnGetLastModified(), OnPatch(), and Service().

~TdjWebComponent()

TdjWebComponent::~TdjWebComponent

(

)

References TdjWebComponent().

Member Function Documentation

GetSession()

TIdHTTPSession TdjGenericWebComponent::GetSession ( TdjServerContext Context, TdjRequest Request, TdjResponse Response, const Boolean Create = True )

inherited

Get or create a HTTP session.

Note

it requires the current TdjServerContext so calling it from one of the HTTP method handlers is not possible. It can be called from the Servive method.

if the context was created with the Auto Session option, this method will always return a session independent of the Create parameter

Parameters

Context	HTTP server context
Request	HTTP request
Response	HTTP response
Create	if True, create a session if no one exists

Returns

HTTP session

GetWebComponentConfig()

IWebComponentConfig TdjGenericWebComponent::GetWebComponentConfig ( )

inherited

Returns a IWebComponentConfig object, which contains initialization parameters for this component.

Exceptions

EWebComponentException

if the method is called before the component has been initialized.

Implements IWebComponent.

Init() [1/2]

TdjGenericWebComponent::Init ( )

inherited

A convenience method which can be overridden so that there is no need to call inherited Init(config).

Init() [2/2]

TdjGenericWebComponent::Init ( const IWebComponentConfig Config )

inherited

Called by the container on startup.

Note

if this method is overridden, the overriding code must also call inherited Init.

Parameters

Config

the configuration

Exceptions

EWebComponentException

if initialization failed

Implements IWebComponent.

Referenced by ~TdjGenericWebComponent().

OnDelete()

TdjWebComponent::OnDelete ( TdjRequest Request, TdjResponse Response )

protected

Called by the server to handle a DELETE request.

Parameters

Request	The HTTP request to process
Response	The HTTP response to fill

Exceptions

EWebComponentException

if an exception occurs

OnGet()

TdjWebComponent::OnGet ( TdjRequest Request, TdjResponse Response )

protected

Called by the server (via the service method) to allow a component to handle a GET request.

OnGetLastModified()

TDateTime TdjWebComponent::OnGetLastModified ( TdjRequest Request )

protected

Returns the time the WebComponent object was last modified.

If the time is unknown, this method returns 0 (the default).

WebComponents that support HTTP GET requests and can quickly determine their last modification time should override this method. This makes browser and proxy caches work more effectively, reducing the load on server and network resources.

Parameters

Request

HTTP request

Returns

the last modified timestamp

References TdjWebComponent().

OnHead()

TdjWebComponent::OnHead ( TdjRequest Request, TdjResponse Response )

protected

Called by the server (via the service method) to allow a component to handle a HEAD request.

OnOptions()

TdjWebComponent::OnOptions ( TdjRequest Request, TdjResponse Response )

protected

Called by the server (via the service method) to allow a component to handle a OPTIONS request.

OnPatch()

TdjWebComponent::OnPatch ( TdjRequest Request, TdjResponse Response )

protected

Called by the server to handle a PATCH request.

Parameters

Request	The HTTP request to process
Response	The HTTP response to fill

Exceptions

EWebComponentException

if an exception occurs

See also

http://tools.ietf.org/html/rfc5789

References TdjWebComponent().

Referenced by OnPost().

OnPost()

TdjWebComponent::OnPost ( TdjRequest Request, TdjResponse Response )

protected

Called by the server to handle a POST request.

Parameters

Request	The HTTP request to process
Response	The HTTP response to fill

Exceptions

EWebComponentException

if an exception occurs

References OnPatch().

OnPut()

TdjWebComponent::OnPut ( TdjRequest Request, TdjResponse Response )

protected

Called by the server to handle a PUT request.

Parameters

Request	The HTTP request to process
Response	The HTTP response to fill

Exceptions

EWebComponentException

if an exception occurs

OnTrace()

TdjWebComponent::OnTrace ( TdjRequest Request, TdjResponse Response )

protected

Called by the server to handle a TRACE request.

Parameters

Request	The HTTP request to process
Response	The HTTP response to fill

Exceptions

EWebComponentException

if an exception occurs

Service()

TdjWebComponent::Service	(	TdjServerContext	Context,
		TdjRequest	Request,
		TdjResponse	Response )

Handle a HTTP request.

The status code of the response always should be set for a component that throws or sends an error.

Note

a custom Web Component should not override this method.

Parameters

Context	HTTP server context
Request	HTTP request
Response	HTTP response

Exceptions

EWebComponentException

if an exception occurs that interferes with the component's normal operation

Implements IWebComponent.

References TdjWebComponent().

Member Data Documentation

Config

IWebComponentConfig TdjGenericWebComponent::Config

inherited

Referenced by ~TdjGenericWebComponent().