Update AlphaTcl Help

Version:	9.0a1
Last update:	2015-12-24 09:41:55

This document explains how to update the AlphaTcl library embedded in Alpha.

Introduction
Instructions
Technical details

Introduction

AlphaTcl is the open-source library of Tcl scripts that implements most of Alpha's functionality. The fact that most of Alpha's functionality is implemented in Tcl scripts make it easy to modify Alpha, and implementing a new feature or fixing a bug is mostly done in AlphaTcl. For this reason, the AlphaTcl library is frequently revised, and these revisions can easily be retrieved and installed into you copy of Alpha, as described in this document.
The AlphaTcl library is hosted by SourceForge inside the AlphaCocoa project and its files are controlled by Subversion (aka svn) which is a version control system. In order to access this repository and retrieve the most recent version, you need the Subversion svn client installed on your machine. It comes preinstalled with Mac OSX 10.5 or higher.

Instructions

To update the AlphaTcl library, go to the submenu Update AlphaTcl in the application menu (that is the AlphaCocoa menu). This submenu has three relevant commands:

User Update
Developer Checkout
Developer Update

If you plan to update only once, the first command is recommended. If you if plan to update frequently, use first the Developer Checkout (and subsequently Developer Update).
The first time you interact with the SourceForge Subversion server, you may be prompted to accept a server certificate, and you have to press P to proceed. (Don't worry about messages like "Error validating server certificate". It isn't really an error, it just means your computer doesn't recognise the SourceForge server, which after all is natural if it never interacted with it before.)

Technical details

Here is exactly what the menu items do:

The User Update item executes an svn export command. This means retrieving the most recent contents of the repository without any Subversion administrative files. This is appropriate for users who just want a fresh version of the files and do not need to place them under version control.
The Developer Checkout item executes an svn checkout command. This means retrieving a complete working copy including the Subversion administrative files. This is required for developers who make modifications in the AlphaTcl library and want the files to be under Subversion control (in order to commit their changes to the repository), and is also the most convenient for anyone doing frequent updates. You only execute a Developer Checkout once: subsequently you use the Developer Update item instead.
The Developer Update item executes an svn update command. This is only possible if previously a checkout command has been issued, so that the files are already under Subversion control. The svn update command only retrieves the files that have been modified in the repository.