On 7/16/11 3:14 PM, David Myers wrote:
Dear subversion,I have recently started a new post and I am in the process of investigating some possible new working practices. This particularly relates to document control. I have read in various places about the 'tagging' system (where by I can use a property to effectively 'name' a file) used by subversion and things such as svn:needs-lock that forces any user who tries to commit a change to a file to be asked to acquire the lock that the file holds. These almost fit my requirements, but not quite. What I require is a method where I can make the file truly 'read only' after a certain point. From what I have read in various places I thing I understand that... subversion reflects the unix style permissions on it's subdirectories, in the subversion directory tree. If I want to make a specific location 'read only' I need to do this from a new directory, and then files in this directory will acquire the permissions of the parent directory. subversion doesn't store the file permissions of a file directly it stores it within the svn:properties However if the above statement is correct this may not fill my requirements. Let me expand on my problem (situation). A group of users may be working on a file over time. At a certain point they all agree that the file is up to its required needs and they formally create a hard copy of this file, and store it as a controlled document (signed and counter signed blah blah blah). The finalised hard copy of the file must be an exact match of the copy stored electronically. All the users will be aware that this file shouldn't be change on the disk. But life being life when a user opens the file to print it they may inadvertently add a space in a paragraph, or an accidental carriage return, or worse how often have you been working on document1 when you get that phone call to ask about a specific part of the controlled document2, so you open the document to have a quick read and clarify the situation. Then you get distracted by something else and you return and start editing the document2, thinking you are editing document1. We all know it shouldn't happen but it does occasionally. What I want to be sure of is that even if this is done by accident there is no way that the file on disk in the subversion repository can be inadvertently changed. The svn:need-lock property combined with another personal property (something along the lines of CtrlDoc:DO_NOT_CHANGE TRUE ), unless there is an svn:read-only property that I am yet to come across! I feel that the combination of these properties and proper use of the Head, commit and branch strategies should enable myself and my users to ensure that these types of problems don't occur. Please help me clarify this so as I can propose the use of a subversion to my colleagues, and give eloquent and correct answers to any of their queries.
First, subversion provides mechanisms to check for changes against a specified revision and to retrieve specified revisions into your working copy. Perhaps you can formalize the way you specify the revision(s) you want to be using or add checks for changes in files subsequent revisions in your workflow and relax the requirement to disallow changes. Version control systems are more about tracking changes than preventing them. If you ask for a specific revision it will always be the same regardless of changes in subsequent changes. Tags are sort-of a special case of this where a directory at a certain revision is copied to a name where you reference it more easily - but you'd get exactly the same results if you retrieved the source directory of the tag copy and specified the revision number. Because of the way tags are used, they are normally not modified after the copy that creates them, either just by convention or by a pre-commit hook that disallows changes to existing files. If you want to tweak things at that level, you could modify your pre-commit hook script to prevent changes to any files you want.
-- Les Mikesell lesmikes...@gmail.com
