Any Docs for THTMLDatasetContentProducer
lazarus / 38-Networking and Web Programming

----------------------------------------------------------------------
Michael Collier · 2012-02-24 17:05

I'd like to try THTMLDatasetContentProducer but didn't find anything
on the wiki. Specifically I need details for producing the content, I
guessed a few methods but didn't work.

I tried the ProduceContent method (raised exception), do I need to use
the other events to produce anything? The source mentions that this
method is for testing only?

The cgi works in all other respects, I can handle the action, open
connection to MySQL, open query, etc and have set the actions
ContentProducer property to HTMLDatasetContentProducer1

I was expecting/hoping to do something like this for the action
OnRequest event
Response.Content := HTMLDatasetContentProducer1.ProduceContent;
Handled := True

I can use HTML by hand and produce a <table></table> but would prefer
to use this component

----------------------------------------------------------------------
devEric69 · 2020-05-14 07:27

Quote from: Michael Collier on February 24, 2012, 06:05:21 pmI was
expecting/hoping to do something like this for the action OnRequest
event
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
AResponse.Content :=
HTMLDatasetContentProducer1.ProduceContent;Handled := True;I can use
HTML by hand and produce a <table></table> but would prefer to use
this component

Assuming that there is a TWebAction named act_get_my_html, you must
ask to write in AResponse, the return of an internal stream (when
answering with html Producer objects solution, we must use the methods
of the writer, which manages a memory stream for a purpose of
rapidity; no string type here like with the fpTemplate solution which
uses text \ string processing in the Php way) by a recursive " foreach
" that traverses the polymorphic objects of the THtmlCustomElement \
TDOMElement hierarchy written by aWriter forming a DOM Tree, with this
call ( it's the Producer's job to convert its internal stream into
text in the response; that's how the pattern was designed, although
there is a text-html rendering method for debugging purposes only;
caution: sometimes it returns '' in some overriden ProduceContent
methods of the html DOM elements  ):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TFPWebModule1.act_get_my_htmlRequest(Sender: TObject; ARequest:
TRequest; AResponse: TResponse; var Handled: Boolean);begin 
HTMLEntityProducer1.HandleRequest(ARequest, AResponse, Handled); 
Handled := True;end;
~~~~~~~~

Here is another example, always with an html Producer object, allowing
to create a web application RAD way, i.e. with drag-drop of
components:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TFPWebModule1.HTMLEntityProducer1WriteEntity(Sender:
THTMLContentProducer; aWriter: THTMLWriter);begin  aWriter.Startbody; 
  aWriter.Startparagraph;      aWriter.heading2('Hello, world from
inside §1');      aWriter.Text('Here is text written inside the
current paragraph.');    aWriter.Endparagraph;   
aWriter.paragraph('This is another text written inside a self "started
and ended paragraph.');    aWriter.Startparagraph;     
aWriter.heading2('Hello, world from inside §2');     
aWriter.Text('Here is the final text.');    aWriter.Endparagraph; 
aWriter.Endbody;end;
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TFPWebModule1.act_get_my_htmlRequest(Sender: TObject; ARequest:
TRequest; AResponse: TResponse; var Handled: Boolean);begin  (*    ask
HTMLEntityProducer1 for its objects DOM tree 's stream content:  *) 
HTMLEntityProducer1.HandleRequest(ARequest, AResponse, Handled); 
Handled := True;end;

----------------------------------------------------------------------
egsuh · 2020-06-08 11:43

Any progress on this? I'm looking at this component, to review the
content of a dataset via web.
I think this should display the content of a dataset in tabular
format, without any further codes, but not.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  
 datasource1.dataset := sqlitedataset1;    dsetcont.datasource :=
datasource1;   webaction1.contentproducer := dsetcontent;   //
dsetcontent = THTMLDataSetContentProducer   

Using aWriter.... works for THTMLEntityProducer,  but not for
THTMLDataSetContentProducer.

----------------------------------------------------------------------
devEric69 · 2020-06-08 15:33

For information, not knowing what you know about this component.

I tried to make this component 100% operational, 2 weeks ago (I gave
myself 2 days, not having more time; so I copied the unit in my
project directory, and debugged it with LazLogger and "raise
HTMLException"). The problem is the time - as usual - to find the
0,???1% of lines to modify ^^.

Indeed, I think that writing with HTML words encapsulated in Pascal
objects rather than using the template engine, only makes sense to me
if it saves time. For a newbee - i know you're not - who doesn't know
Web programming, but who knows how to create a database and how to
create a .htaccess and a .htpassword files, using this component saves
time.

Quickly, from memory, roughly the idea seemed to me to be that we
should create an HTML table (loop on SQL records, to create each HTML
row), with creation of an "edit" button in the last column of each
HTML row.
There's a inter-pages HTML navigator provided, that can present, HTML
table URL by HTML table URL, all x records of an SQL table.

The "edit" button of each HTML row calls a server-side web action,
which should display the single row for its edition (labels column,
followed by the html controls column for input). And there should be 
two buttons "save changes" and "undo changes".

It's very far from ajax, but it's RAD which allows to hide technical
problems for someone who wants to quickly publish and manage a SQL
table, on the web or on an intranet.

nb: when editing, it's called THTMLDatasetEditContentProducer i.e.
it's one step further.