asked on

Extracting text only (500 points)

The user clicks on a list of files in a listbox and, if it is human readable (.txt, .doc, .htm, html, pdf), the text is extracted and displayed in a memo. Just the plain text without anything else.

Either the code or a component.

I am using Delphi Starter XE.

Many thanks for your help.

Mahdi78

Try this

procedure TForm1.ListBox1Click(Sender: TObject);
begin
if ExtractFileExt(ListBox1.Items[ListBox1.ItemIndex]) = '.txt' then
Memo1.Lines.LoadFromFile(ListBox1.Items[ListBox1.ItemIndex]);
end;

Ephraim Wangoya

This depends on what type of data you are loading
If its a simple txt file then its very simple

Text file

var
  List: TStringList;
begin
  List := TStringList.Create;
  try
    List.LoadFromFile(ListBox.Items[ListBox.ItemIndex]);
    Memo1.Lines.Assign(List);
  finally
    Lidt.Free;
  end;
end;

Open in new window

jimyX

The only human readable files in the Memo can be txt but the others .doc, pdf will not htm/html will show the HTML scripts as well.

You need special handling for each file type.

Mahdi78

As jimyx said, you will read just txt files as plain text, so if you want to read html code or binary text of pdf this code is exactly what you want

procedure TForm1.ListBox1Click(Sender: TObject);
const MyExt = '.txt.doc.pdf.html.htm';
begin
if Pos(ExtractFileExt(ListBox1.Items[ListBox1.ItemIndex]), MyExt) > 0 then
Memo1.Lines.LoadFromFile(ListBox1.Items[ListBox1.ItemIndex]);
end;

Ephraim Wangoya

For files like pdf or html, you have to know how to remove the tags but this is not really worth it.
Its much better to use a viewr for each type of file, eg TWebbrowser, TOleContainer, TRichEdit etc

var
Buffer: string;
Stream: TFileStream;
I: Integer;
begin
Stream := TFileStream.Create(ListBox.Items[ListBox.ItemIndex], fmOpenRead);
try
SetLength(Buffer, Stream.Size);
Stream.Read(Pointer(Buffer)^, Size);

//here you would have to strip out the tags depending on what tye of file you opened

memo1.Lines.Add(Buffer);
finally
FreeAndNil(Stream);
end;

rincewind666

ASKER

An example for a htm file:

I need "I want just this text to be extracted" in the memo, using the following html file( the same principle for doc and pdf files without any tags):

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<meta content="en-gb" http-equiv="Content-Language" />
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>Untitled 1</title>
</head>

<body>

I want just this text
to be extracted

</body>

</html>

jimyX

There is one component I know which can help you here:
http://atorg.net.ru/delphi/atviewer.htm

It reads all the mentioned formats and even more.

Ephraim Wangoya

As I said, this is not trivial, the tags in a PDF file are not the same as the tags in a HTML file. MS word files are binary so you wont get much out of them.

You really need a viewer to do this, just use a TOleContainer, that should be able to display all types of files

ASKER CERTIFIED SOLUTION

Mahdi78

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rincewind666

ASKER

Many thanks for your help.

rincewind666

ASKER

Many thanks for your help.

A note to jimyx: Thanks for the link to the atviewer component. It looks great and would have been used but it is not compatable with Delphi XE. A great shame. Anyway thanks for your help.