README

Extension to Delphi's built-in TFileStream that allows fmAppend and fmAppendExisting open modes.

(C) 2018 HeartWare

Distributed under Creative Commons License CC-BY-SA.

Generally speaking this grants you a limited right to use this software - also commercial use - as long as you attribute the author in your documentation. Also, if you change the software (f.ex. to suit your specific needs) you must make available your modifications under a license not stricter than the original license the work was distributed under.

Read more here:

https://en.wikipedia.org/wiki/Attribution_(copyright) - BY (Attribution) https://en.wikipedia.org/wiki/Share-alike - SA (Share-Alike)

Requirements: A UNICODE Delphi compiler (ie. Delphi 2010 or later).

Usage: Simply include the HeartWare.FileStream unit in your project. Your existing code should continue to work as previously, but you now have a few extra Modes that you can use:

fmAppend - Opens (or creates) the file and moves the file pointer to the end of the file, ready to append data to the file. fmAppendExisting - Opens an existing file in Append mode. Identical to fmAppend, except that the call fails with an exception if the file does not already exist.

In addition to these two new modes, the new TFileStream also supports overloaded constructors that allow you to specify an Encoding scheme to use for writing text to the file. Since the main usage for appending files is LOG files, I have made a few extensions that makes it easier to do so:

TFileStream.WriteLine(CONST S : STRING) - Writes the string to the file TFileStream.WriteLine(CONST Format : STRING ; CONST Args : ARRAY OF CONST) - Writes a formatted string to the file (like Format function) TFileStream.TW - The built-in TTextWriter. You can use this to access all the other methods of the internal TTextWriter. The above two methods are simply gateways to the appropriate overloaded TW.WriteLine. CLASS VAR TFileStream.DefaultEncoding - Use this to once and for all specify the default encoding to use on all created TFileStream instances. If not set by you if will default to TEncoding.Default (ANSI on Windows, UTF-8 on MAC). FUNCTION DefEncoding : TEncoding - VIRTUAL function that allows you another method of specifying default encoding. If you have the need for various encodings on different TFileStream instances, you can subclass the new TFileStream with your own and OVERRIDE this function. Do NOT call the inherited function, unless you want to only have your own implemtation active in certain configurations. FUNCTION CreateTextWriter(Encoding : TEncoding) - VIRTUAL function that you can override in a subclassed TFileStream if you need a specific TTextWriter descendant instead of the default one used (TStreamWriter).

Beisdes these extensions, there is also these VIRTUAL methods:

FUNCTION DefaultShare(Mode : Cardinal) - For CONSTRUCTOR calls that don't have a Sharing parameter, this VIRTUAL function is called to determine the default sharing mode. As it is, it will return fmShareDenyWrite for fmAppend and fmAppendExisting modes, and fmShareCompat for other modes.