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.NameList property returns nil #189

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
Place a THTMLViewer, TMemo and TButton component on a form.  Load a local HTML 
file:

  HtmlViewer1.LoadFromFile('c:\temp\sample.html');

Then add a Button click event:

procedure TformMain.Button1Click(Sender: TObject);
begin
  Memo1.Text := HtmlViewer1.NameList.Text;
end;

You will see that nothing is placed into the TMemo.  The Namelist is empty 
rather than containing hyperlink information.

Also, OrphanCat had previously suggested the following in order to get 
information about the links within a loaded HTML document:

Bernd: THtDocument.IDNameList offer the list of bookmarks incl. their YOffsets

The problem is, there is no documentation on how to us the IDNameList. We've 
tried the following, and always get nil:

  Memo1.Text := HtmlViewer1.SectionList.IDNameList.Strings[0]

  Memo1.Text := String(HtmlViewer1.SectionList.IDNameList.AnsiStrings);

  Memo1.Text := HtmlViewer1.SectionList.IDNameList.Text;

  Memo1.Text := HtmlViewer1.SectionList.IDNameList.Names[0];

I fail to see any way to obtain information about the hyperlinks on a currently 
loaded HTML document.

Original issue reported on code.google.com by xyz.123....@gmail.com on 6 Sep 2012 at 3:43

GoogleCodeExporter commented 9 years ago 
Hi xyz,

it would be easier to answer if I had a copy of c:\temp\sample.html.

HtmlViewer.NameList:ThtStringList (which references its document's 
IDNameList:TIDObjectList) collects ID attributes of all tags and name 
attributes of A tags. The strings contain the uppercased ID resp. NAME and the 
corresponding object is a TIdObject derivate.

OrphanCat

Original comment by OrphanCat on 7 Sep 2012 at 5:00

GoogleCodeExporter commented 9 years ago 
Hi xyz,

thanks for the sample.html.

With this procedure:

procedure TFormLiveHtml.NameList1Click(Sender: TObject);
var
  Infos: TStringList;
  Names: TIDObjectList;
  I: Integer;
begin
  // simply get the names
  //Clipboard.AsText := HtmlViewer.NameList.Text;

  // get the names and the actual types of the associated TIDObject derivates.
  Infos := TStringList.Create;
  try
    Names := HtmlViewer.SectionList.IDNameList;
    for I := 0 to Names.Count - 1 do
      Infos.Add(Names.Strings[I] + ' (' + Names.Objects[I].ClassName + ')');
    Clipboard.AsText := Infos.Text;
  finally
    Infos.Free;
  end;
end;

I'm getting this result from the ClipBoard:

0 (TChPosObj)
1 (TChPosObj)
10 (TChPosObj)
11 (TChPosObj)
12 (TChPosObj)
13 (TChPosObj)
14 (TChPosObj)
15 (TChPosObj)
16 (TChPosObj)
17 (TChPosObj)
18 (TChPosObj)
19 (TChPosObj)
2 (TChPosObj)
20 (TChPosObj)
21 (TChPosObj)
22 (TChPosObj)
23 (TChPosObj)
24 (TChPosObj)
25 (TChPosObj)
26 (TChPosObj)
27 (TChPosObj)
28 (TChPosObj)
29 (TChPosObj)
3 (TChPosObj)
30 (TChPosObj)
31 (TChPosObj)
32 (TChPosObj)
33 (TChPosObj)
34 (TChPosObj)
35 (TChPosObj)
36 (TChPosObj)
37 (TChPosObj)
38 (TChPosObj)
39 (TChPosObj)
4 (TChPosObj)
40 (TChPosObj)
41 (TChPosObj)
42 (TChPosObj)
43 (TChPosObj)
44 (TChPosObj)
45 (TChPosObj)
451 (TChPosObj)
453 (TChPosObj)
46 (TChPosObj)
466 (TChPosObj)
6 (TChPosObj)
65 (TChPosObj)
7 (TChPosObj)
8 (TChPosObj)
9 (TChPosObj)
ABUZZ (TChPosObj)
AZANS (TChPosObj)
ZERO (TChPosObj)
ZOON (TChPosObj)

which seems to be okay.

OrphanCat

Original comment by OrphanCat on 12 Sep 2012 at 8:55

GoogleCodeExporter commented 9 years ago 
OrphanCat,

Thank you for providing an example of how to access the NameList properties of 
the contents of THTMLViewer.  What I really would like to learn is how to 
obtain the properties of NameList items in the current THTMLViewer VIEW window. 
I need to be able to determine the range of items within the current view, not 
the entire document.

Original comment by xyz.123....@gmail.com on 15 Sep 2012 at 12:38

GoogleCodeExporter commented 9 years ago 
Hi,

you might be interested in ThtDocument.PositionList resp. 
ThtDocument.FindSectionAtPosition(). PositionList is a TList containing objects 
based on TSectionBase. It is used in FindSectionAtPosition() to find the last 
section starting at or above a given YPosition.

For example:

SectionFrom := HtmlViewer.SectionList.FindSectionAtPosition( 
  HtmlViewer.VScrollBar.Position, 
  SectionYPosition1, SectionIndexInPositionList1);
SectionTo := HtmlViewer.SectionList.FindSectionAtPosition( 
  HtmlViewer.VScrollBar.Position + HtmlViewer.PaintPanel.Height - 1, 
  SectionYPosition2, SectionIndexInPositionList2);

gets first and last section within the view.

Most probably this is still not the whole story you need, but it might get you 
closer to it...

As to the empty NameList: is this issue been solved?

OrphanCat

Original comment by OrphanCat on 11 Oct 2012 at 9:24

GoogleCodeExporter commented 9 years ago 
>> As to the empty NameList: is this issue been solved?

Yes, it has.  Thank you.

Original comment by xyz.123....@gmail.com on 13 Oct 2012 at 1:52

GoogleCodeExporter commented 9 years ago 
>> For example:
>> SectionFrom := ...
>> gets first and last section within the view.

Thanks, but unfortunately your code snippet isn't sufficient for me to figure 
out how to implement the example.

Original comment by xyz.123....@gmail.com on 13 Oct 2012 at 1:59

GoogleCodeExporter commented 9 years ago

Original comment by OrphanCat on 26 Apr 2014 at 10:12