* Description of the fpweb system

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.gitattributes

@@ -1057,6 +1057,7 @@ fcl/unix/resolve.inc svneol=native#text/plain
 fcl/unix/simpleipc.inc svneol=native#text/plain
 fcl/web/Makefile svneol=native#text/plain
 fcl/web/Makefile.fpc svneol=native#text/plain
+fcl/web/README svneol=native#text/plain
 fcl/web/custcgi.pp svneol=native#text/plain
 fcl/web/fpcgi.pp svneol=native#text/plain
 fcl/web/fpdatasetform.pp svneol=native#text/plain

fcl/web/README

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+This is the beginning of a server side web system for FPC.
+Although it is non-visual, it is geared towards use in Lazarus.
+
+Architecture:
+
+htmldefs
+--------
+(in ../inc) contains basic HTML declarations.
+
+httpdefs
+--------
+contains the basic HTTP system definitions: 
+header field names
+TCookie(s): 
+  collection with cookies in web request
+TUploadedFile(s): 
+  collection with uploaded files in request
+THTTPHeader:  
+  Class describes HTTP Request/Response headers.
+  it has properties for all possible HTTP headers, including cookies
+TRequest: 
+  Descendent of THTTPHeader, describes client request.
+  Contains uploaded files.
+TResponse: 
+  describes the web server response. Includes headers and contents. 
+TCustomSession: 
+ Base for all session components.
+
+fphttp:
+-------
+Basic web system components/classes
+
+TCustomHTTPModule: 
+  Abstract TDataModule descendant, which processes a webrequest
+  and prepares a response.
+TModuleFactory/TModuleItem: 
+  Module registration and creation system.
+TCustomWebAction(s): 
+  Webactions.
+RegisterHTTPModule():
+  routine registers a module with the web system.
+THTTPContentProducer : 
+  abstract HTTP producer component.
+
+The idea is that the URL relative to the server is taken and parsed as
+follows
+http://www.server.org/Path1/Path2
+
+Path1 determines which module in the system is created to handle the
+request. (the factory is queried)
+Path2 determines which web action inside the module is used to handle the
+request. (implemented in TWebModule, see fpweb)
+
+websession
+----------
+Implements basic session support.
+
+TSessionHTTPModule:  
+  TCustomHTTPModule descendent with session support.
+TIniWebSession: 
+  TCustomSession descendent which stores session variables in inifiles.
+TFPWebSession:  
+  TIniWebSession descendent for use in fpweb. Uses cookies to store session info.
+GetDefaultSession() : 
+  returns default session object.
+
+fptemplate
+----------
+Unit which implements template support.
+
+TTemplateParser: 
+  Template parse object. Does the actual parsing and replacing. Delimiters
+  are configurable. Standard variables can be specified, callbacks for unknown
+  values can be set.
+
+TFPCustomTemplate:
+  TPersistent for use in components. Allows properties to configure the
+  TTemplateParser. Supports streams, template and template files.
+
+fpweb
+-----
+Actual usable implementation of TCustomHTTPModule. 
+
+TFPWebAction(s): 
+  Web actions with template support.
+TCustomFPWebModule: 
+  Descends from TSessionHTTPModule, implements WebActions and has template support.
+TFPWebModule: 
+  published TCustomFPWebModule properties for use in Lazarus.
+
+fphtml
+------
+This creates web modules specialized in creating HTML content.
+
+THTMLContentProducer: 
+  Descendent of THTTPContentProducer which produces HTML
+THTMLCustomDatasetContentProducer: 
+  Descendent of THTTPContentProducer which produces HTML from datasets.
+THTMLDatasetContentProducer: 
+  Descendent of THTMLCustomDatasetContentProducer which publishes some 
+  properties.
+THTMLSelectProducer:
+  Produces a combo box.
+THTMLDatasetSelectProducer
+  Produces a combo box bases on values in a dataset.
+TCustomHTMLModule:
+  TCustomHTTPModule descendent which produces HTML content only.
+
+htmlelements
+------------
+
+Implements a DOM for HTML content. Contains a TDOMElement descendent for
+all valid HTML 4.1 tags.
+
+THtmlCustomElement:
+  Basis for all HTML tag elements.
+THTMLDocument:
+  TDOMDocument descendent
+THTMLIDElement:
+  element representing <ID> tag 
+
+All tags are in tagsintf.inc.
+
+htmlwriter
+----------
+
+Implements a verified HTML producer.
+
+THTMLwriter:
+  This is a class which allows to write certified correct HTML.
+  It works using the DOM for HTML.
+  It also has forms support.
+
+Writing HTML is done as follows:
+
+  StartBold;
+  Write('This text is bold');
+  EndBold;
+or
+  Bold('This text is bold');
+
+But the following is also possible
+  Bold(Center('Bold centered text'));
+
+Open tags will be closed automatically.
+
+wtagsintf.inc contains all possible tags.
+
+fpdatasetform
+-------------
+
+This contains classes which allow to create complicated HTML/forms 
+based on a TDataset.
+
+THTMLDatasetFormProducer
+  Creates an edit form for a TDataset record.
+  Complicated table layouts are possible.
+
+THTMLDatasetFormGridProducer
+  Creates a grid with data from a TDataset
+  Complicated table formatting is possible.
+
+
+custcgi:
+--------
+  CGI application base class. It knows nothing of the fp
+  HTTP module system.
+
+TCustomCGIApplication : 
+  TCustomApplication descendent which handles a CGI request.
+  No instance of this class is created, this is done in fpcgi.
+
+TCGIRequest:
+  TRequest descendent which retrieves content from the CGI 
+  environment.
+
+TCGIResponse:
+  TResponse descendent which returns content to the CGI environment.
+
+fpcgi:
+------
+  Standard CGI application instance.
+
+TCGIApplication:
+  TCustomCGIApplication descendent which uses the fpWeb system
+  to create a TCustomHTTPModuleClass to handle the request.
+
+It contains an Application instance which handles everything.