I know a lot of questions have been asked about VB6 migration (and I've read most of them), but I'm still not entirely certain on what the best way to go about this is.
We have a client that we built an order tracking application for about a decade back and they came to us this week saying they were having some issues with it. The app was written entirely in VB6, which has been something of a hassle as tracking down the necessary tools to work with a project so old took some considerable effort. In an effort to make any future maintenance less of a headache, my boss wants to pitch the idea to them of updating the app to .net and wants to know what exactly that would entail. I've never done anything like this before, but what I've read (both here and elsewhere) suggests that Microsoft's "auto-update" from VB6 to .net simply doesn't work very well and I'd pretty much have to rebuild the app from the ground up.
To get to the crux of my question: is this the case? Would I pretty much just need to rewrite it, or is there another means of going about this that could/would save me a lot of time/effort?
Any insight would be greatly appreciated.
VB6 and VB.NET are radically different. The syntax has changed, and so has the underlying structures, forms, custom controls, and almost every single aspect you can possibly think about.
A complete redesign and reassessment of needs and functionality is imperative. With .NET the plethora of new libraries and features supersede the antiquated VB6 libraries, OCXs, etc. Also if you feel bold, you can migrate your code to C# and other CIL languages aside from VB.
Out of hand, the Microsoft migration tool will not do much. Moreover, it also depends on whether you have your business logic well separated from your GUI. Otherwise, it will make it even harder. Depending on the size of your application, it might make it quite expensive. Another possible solution you might consider is to run your app in a virtual environment or on a remote app http://technet.microsoft.com/en-us/library/cc730673(v=ws.10).aspx that will ease the deployment pain.
I have also researched this topic.
Try the smart rewrite solution that converts 95% of the code automatically.
first, run your app through the assessment wizard to determine estimated costs and resources needed.
http://visualwebgui.com/Gizmox/Solutions/InstantbCloudmoveb/tabid/744/Default.aspx
There are a huge number of components that come with Delphi (XE2), many have been around for along time. Which components should be avoided (the BDE Components for instance), which are out of date (TXPManifest?), and which should be avoided because they are unusable or will just cause grief?
Anything for which you don't have the source. Nothing says "frustrate me" more than not being able to figure out why a component is behaving the way it is because it's poorly documented and being stuck on an old Delphi version because I can't recompile it.
Anything you don't absolutely need.
I am currently maintaining a large application that is dependent on a variety of 3rd party components. In order to upgrade the application, you need to upgrade the components. In the case of vendors that are no longer in business, that's a problem. As a result the entire application is stuck in limbo.
I used to use Pythia to obfuscate my D6 program. But it seems Pythia does not work anymore with my D2007.
Here's the link of Pythia (no update since early 2007) : http://www.the-interweb.com/serendipity/index.php?/archives/86-Pythia-1.1.html
From link above, here's what I want to achieve
Over the course of time, a lot of new language features were added.
Since there is no formal grammar available, it is very hard for tool vendors (including Embarcadero themselves) to keep their Delphi language parsers up at the same level as the Delphi Compiler.
It is one of the reasons it takes tool vendors a bit of time (and for Delphi generics support: a lot of time!) to update their tools, of they are update at all.
You even see artifacts of this in Delphi itself:
the structure pane often gets things wrong
the Delphi modelling and refactoring sometimes fails
the Delphi code formatter goes haywire
Pythia is the only obfuscator for the native Delphi language I know of.
You could ask them on their site if they plan for a newer version.
Personally, I almost never use obfuscators for these reasons:
reverse engineering non-obfuscated projects is difficult enough (it would take competitors long enough to reverse engineer, so the chance to lessen the backlog they already have in the first place is virtually zero)
their added value is limited when you have multi-project solutions (basically they only hide internal or private stuff)
they make bug hunting production code far too cumbersome
--jeroen
You may try UPX - Ultimate Packer for Executable). It will compress the resources and all the text entries are non-readable without de-compress first.
I don't know any good free solutions, but if you really need some protection you can always buy something like:
http://www.aspack.com/asprotect.html
or
http://www.oreans.com/themida.php
We have a medium-to-large size application. One version runs on Delphi 6 and another one on Delphi 2006.
One argument would be support for Unicode. We need that to cater to Customers around the world.
Other things I have read about are: better IDE (stability, speed), better Help and some cool additions to the language (e.g.: generics)
What about third-party components? We use DevExpress, DBISAM and many others. Are these already ported?
Touch/Gestures sound cool, but we have no use for that in our application.
Better theme support (eg., TStringGrid/TDBGrid now support themes).
Support for Windows Vista and Windows 7, including support for the Direct2D Canvas in Win7 and the Touch/Gesture support you mentioned.
Improved refactoring, including support for refactoring generics.
Built-in source code formatter.
IDE Insight allows you to find things in the IDE itself.
Enhanced RTTI.
Improvements in the debugger, including new custom data visualizers and the ability to create your own. There are two included with source (one for TDateTime and one for TStringList). Also better support for debugging threads, including the ability to name threads for debugging and set breakpoints on specific threads.
The ability to add version control support to the IDE via interfaces. This will allow version control developers to add support directly in the IDE itself.
The help is much better than in previous versions. It's been completely redesigned again, and is much more comprehensive and complete. There's also an online wiki-based version (used to generate the help itself) that you can add or edit.
Background compilation allows you to continue working while you're compiling your project.
As far as third party controls, that's up to the specific vendor; you'll have to check to see if Delphi 2010 versions are available for each of them individually. (You might check the Embarcadero web site, though, to see if they have a list already available; I seem to recall hearing of one... Ah, yes. Here it is. )
Last upgrade for old version
With old version of Delphi (before Delphi 2005), you have only before january 1 2010 to upgrade.
After you will have to buy a full version.
Productivity
http://www.tmssoftware.com/site/blog.asp?post=127
Purely as a reactive measure. Lets say that there is a new feature in the latest version of a yet to be released operating system. Lets say that this feature breaks certain features inside your application. IF there was to be a global fix for it, it would most likely not be placed in older versions of the compiler, but the newer versions which "officially" support the new operating system. The largest problem about waiting too long is that when such a measure is needed its generally at the zero hour when sales are at risk.
Upgrade NOW, and help prepare your application to be more reactive to future changes.
Don't convince him for a Delphi 2009/2010 upgrade, Do it for a Software Assurance.
The refactoring tools and overall
speed and stability of the IDE will
make the development team more
productive.
Working with the latest tools will make it easier to recruit top talent.
The IDE is definitely a step up from Delphi 6 and/or Delphi 2006.
If Unicode is important to your customers then Delphi 2009/2010 is a clear option. But if Unicode is important to you, rather than your customers, then I'd be careful.
Unicode is not "free". If your users/customers have concerns w.r.t memory footprint and/or performance, and/or your application involves extensive string handling, then Unicode exacts a price that all your customers will have to pay, and for customers who are not themselves concerned with Unicode support, that price comes with zero benefit (to them).
Similarly if your application sits on top of a currently non-Unicode enabled database schema. Migrating existing databases from non-Unicode to Unicode is non-trivial, and if you have customers with large production databases, incurring downtime for those customers whilst they migrate their data stores is something you should consider carefully.
Also you will need to be very aware of any interfaces to external systems - your code will unilaterally "go Unicode", and that may adversely impact on external interfaces to other systems that are not.
In such cases you would do well to tie the transition to Unicode with other compelling feature improvements and benefits to make the transition compelling for other reasons.
Also, if you genuinely have customers with a real need for true Unicode, then the transition is not as simple as recompiling with the latest/greatest compiler and VCL. True Unicode support will involve a great deal more work in your application code than you might at first appreciate.
Of course, having a Unicode capable compiler/VCL is a crucial component, but it's not an answer on it's own.
The Unicode change has a significant impact on 3rd party components. Even if you have the source to your 3rd party code you may find yourself facing Unicode issues in that code unless the vendor has taken steps to update that code in a more current version. Most current vendor libraries are Unicode by now though I think, so unless you are using a library that is no longer supported by the vendor, you should be OK on that score.
I would also exercise caution when it comes to those "cool" language features such as generics. They sure do look cool, but they have some seriously limiting characteristics that you will run into outside of feature demonstrations and can result in maintenance and debugging difficulties as the experience of the community in working with them is limited, so "best practice" has yet to emerge and the tool support perhaps hasn't yet caught up with the uses to which those features are being put in actual code.
Having said ALL that.... Since you cannot realistically choose any version other than Delphi 2010 to upgrade to, then if you are going to upgrade at all then you have to bite the Unicode bullet and will find yourself presented with lots of tempting language features to tinker with and distract you. ;)
And now that Embarcadero are imposing a more draconian policy w.r.t qualifying upgrade products, you will have to get off of Delphi 2006 if you wish to qualify for upgrade pricing for Delphi 20*11* onward, whether you decide that 2010 is right for you or not, otherwise when the time comes to upgrade to Delphi 2011 you will find yourself treated as a new customer, and if you thought that upgrade pricing was steep, check out the new user license costs!
D2006 was an awful version of Delphi. It's worth upgrading just to be rid of all the memory leaks and random IDE crashes and glitches. Justify it to the boss as a massive decrease in lost productivity. That means less money wasted paying you to not produce code because your dev tools aren't working. It'll pay for itself very quickly on that basis alone.
As for D6 vs. D2010, that's a feature argument. Start with Skamradt's response, that it helps your code be future-proof. Underscore it with OS compatibility. D2007 was the first version that understands Vista. D2010 is the first version to understand Windows 7. If you're compiling with any older version, your app is obsolete before you even deploy it because there's no guarantee it's compatible with modern versions of Windows.
Then you've got actual language features. The main improvements IMO from 2006 to 2010 are Generics, which helps out with all sorts of repetitive tasks, and extended RTTI. Robert Love has been doing some great blog posts lately on how the extended RTTI can simplify common real-world problems. (Plus Unicode, of course.)
Playing the devils advocate, there may be reasons not to upgrade. For instance you might be missing the source to certain components or you may still need to support Win9X.
I think you'll probably find the best reason to upgrade (leaving all the new wizz-bang features aside) is that you'll be significantly more productive in the new IDE. If you don't / can't upgrade I'd recommend grabbing a copy of Castalia, which can give you access to many productivity enhancements (e.g. refactoring) in Delphi 6.
DBISAM is updated, I just emailed them this past week concerning a project I hope to be upgrading from Delphi 3 to Delphi 2010.
All the other packages I looked into upgrading for that project (WPTools, Infopower, TMS) all state on their websites that they offer compatibility with 2010.
I never had D2006 (I have 2007) so I can't speak to any defects in that particular release (D2007 isn't that great, either) but it's generally a good principal to keep your tools in good shape. For a saw that means sharp, for software that means current. Especially in a new-OS year, you probably want the corresponding version of your primary development environment.
It seems to me there are 2 aspects in developing professional applications:
You want to earn money: you have to stick to your customer's demands, keep your stuff KISS, maintainable and so on... You have to be productive: no matter of generics, RTTI, widgets like flowpannel, gesture and so on because it takes time to learn and more time to use. In this way, change from D7 to D2010 is not nessary relevant. Change for another IDE like REAL Basic allowing multiplaform target is more accurate.
BUT as a developer there is a child and a poet in you, fascinated by new technologies or/and algorithms... This is the creative part of the job. You got to be creative if you want to be impressive and innovator. Upgrade to Delphi 2010 is a must have, searching for new classes, new objects is a way of life in today's programming.
That's my humble point of view and the reason that keep me spend my money to upgrade Delphi from I to 2010.
Best regards,
Didier
Lists of compatible components that already support Delphi 2010 including DevExpress (article will be periodically updated from our technology partner database) is at
http://edn.embarcadero.com/article/39864
Argument - tens of thousands of tools and components available for the things you might need in addition to the open api(s) for components and the IDE.
Item 9 of the The Joel Test: 12 Steps to Better Code is:
Do you use the best tools money can buy?
Perhaps this argument is germane here.
On the other hand if you are maintaining legacy code and not generating anything that has dependency on new OS or tool features, it is a hard argument to win. I would not however recommend generating entirely new projects on tools that old.
Unicode has been supported on Windows since at least NT 4.0, and for Windows 95/98/Me since the addition of MSLU in 2001 - so surely Delphi 2006 supports it!? [edit]Not fully supported in the component library it seems.[/edit]
I suggest that the one compelling argument is in order to ensure Vista and Windows 7 compatibility. I understand that 64bit target support was planned for Delphi this year. That may be another argument; but again it only applies if you actually intend to target such a platform, and in a way that will give a tangible benefit over 32bit code. [edit]I emphasised planned because I did no know whether it had made it into the product, but that it might be a consideration for you. It seems it has not, so the argument you put to management might be even less strong.[/edit]
Management are not going to be impressed by the "I just want cool tools to play with", you have to approach it on a "Return on Investment" (ROI) basis. Will you get your product out faster or cheaper using this tool? Are the existing tools a technical barrier to progress? Conversely, consider whether spending time porting your legacy code to new tools (with the associated validation and testing) will kill your budgets and deadlines for no commercial advantage?
I'm interested in finding something out. In Delphi the default since the begining when buying components has been to be able to purchase them with source (even if it might be a slightly more expensive option). This made sense in Delphi for a number of reasons, firstly Borland led the way by providing the full source of the VCL with every install of Delphi, but also having the source was considered essential since when you upgraded Delphi you had to recompile and sometimes Authors went out of business.
I'm interested in finding out whether any Delphi component writers out there have ever had reason to regret selling their component 'with source'? Has someone tried to release a competing product based on your code, or passed it off as their own?
The reason I ask is because it still seems to be the exception rather than the norm to provide a 'with source' option when purchasing an ActiveX control or a .NET assembly. Maybe a reassurance that people don't want the source for nefarious purposes might convince more component writers to allow source code to be purchased along with the component.
I have personal experience with this. I used to sell a component and function library for Delphi (Clipper Functions for Delphi, AKA CFD); we went from version 1 in '96 to version 5 in 2000 when I took a job that wouldn't allow moonlighting. We had 5000+ registered users at the end; I still provide quite a few of them with free updates and occasional bug fixes.
I never had any reason whatsoever for not making source available. In fact, there was no option to purchase CFD without source. I wouldn't buy any commercial Delphi component library that my app would depend on without source, for the very reasons you cite (recompiling with new Delphi releases and vendors going away).
Unless the component writer is using some form of obfuscation the source for any .Net assembly can be obtained by using reflector.
I've used this on assemblies from Microsoft as well as other vendors to track down problems in their code. In some cases I went ahead and patched the problem and recompiled it; but do that at your own peril.
For all Delphi components which I developed over the past 10 years, full source code was always included. It would however be a big advantage to have a compatible binary (DCU) format (similar to Java and .NET) in Delphi for trial versions, or for low cost 'personal editions' - versions which do not attract the real commercial developers, because of the missing source code. Compiling DCUs for Delphi 5,6,7,2006, 2007 and 2009 is possible (if the Delphi licenses are there), but managing so many different code versions requires a lot of work for automatic build and packaging systems ...
I have an issue especially with .Net skinning libraries. I have found none good enough that would include the code for a fairly economic price. I'm talking about prices that go over the $1000USD price line, which I think it´s astronomic for a freelance developer, for just a piece of software. But, those things that are harder to implement in each language are the most expensive as well, so there is a relation between those two factores in the difficulty of implementing something similar your self. I know this is no answer for your question, but my own view of things.
I don't have personal experience with this, but I do know that source code watermarking is available and some vendors have used it. Not sure how successful it would be.
I have never heard news of anyone releasing a competing product with source code from another commercial vendor. It does however happen frequently with open source ones though.