Does Delphi support internationalization in any way?
I've seen that I can add different languages for a project, but that seems to create multiple instances of the dfm files. Am I right that the language therefore cannot be changed at runtime?
How do you handle internationalization (if you do)? Are there any best-practices?
Delphi ships with some tools to do this.
Here is a tutorial for Delphi 2005, and a video of Nick Hodges showing off the more recent version for Delphi 2009.
I have once experimented with runtime change of languages. It worked great, but I needed to write lots of code myself (and circumvent the dfm files). The problem is, it is a lot of hassle and you almost never need this.
The better option (in my opinion) is to create a base language version and use a translator tool for the other language. We use a third party translator that works on the executable and dll. It replaces the strings in the resources and creates new binary files.
One big plus of this tool is that it shows the translated dialogs (standard windows components only) so you have direct feedback if labels are too large.
Amd then there is dxgettext:
http://dxgettext.po.dk/
traditionally one of the tools used to change language runtime without restart.
Note that with Delphi/unicode the amount of code changes with this packages has decreased (one no longer has to change any resourcestring use)
I have been using the SiComponents before. They allow you to change all text independently from the executable. You can embed the diferent languages in your executable (not recomended) or load them from files. There is also an editor to support translation. They are very good, stable, and fast.
In Delphi 2006 under Tools, Options, Translation Tools Options you can configure the translation tools, especially theTranslation Repository. It can be found under View, Translation Manager. All translated strings will be ressource strings and can be stored in language specific dll. Searching the help for Translation Manager will point you in the right direction.
I second the recommendation for using the TsiLang components(www.sicomponents.com). I've just used them to upgrade from English-only to English + Chinese, selectable at run-time, and found the process to be quite a lot easier than I was expecting. The end results are not perfect, but certainly good enough to work with.
Related
I'm writing a program for both Delphi and Lazarus/FreePascal, so I can also reach customers using Linux or Mac OS X.
Is there a cross-platform tool that works in both environments too, so I can add multiple languages?
I tried GNU Gettext for Delphi and C++ Builder, but it does not compile in Lazarus for Mac OS X.
Is there anything comparable?
No, simply since the only system that FPC uses is gettext.
Lazarus afaik uses gettext, also on OS X, but obviously the FPC one, not the delphi one.
I suggest you devote some more attention to getting the gettext solution to work, maybe asking specific questions here.
In reply to your comment:
If I look in the LCL, I see in the translate routines stuff that translates properties of tpersistents, but only for special "TTranslatestrings" fields. So it doesn't seem to translate full forms directly.
Did you have a look at this:?
http://wiki.lazarus.freepascal.org/DxGetText
DKLang Localization Package is an open source project that works very well. It has not been tested under FreePascal, but we would be willing assist with any needed changes.
This one is note entirely free, but parts of it are: (The GUI editor isn't, but the code parts are, and the editor isn't strictly required):
http://www.be-precision.com/products/precision-langs/
I'm porting a app to FreePasal/Lazarus & found that their form converter is not good. I have a small utility app, and each time I do a change I need to reconvert, relayout and reimport graphics. Plus, some things are messed up.
I wonder if exist a automatic tool for convert the DFM files to delphi sourcecode, so I can do this more easily. Is not problem if the sourcecode is not FPC compatible.
The free GExperts plug-in has a "components to code" feature. Install it in your Delphi IDE and open the form you wish to convert. Select the components and invoke the command, and it will place equivalent creation and initialization code on the clipboard for you to paste wherever you need it.
Updating to trunk versions of both Lazarus (0.9.29) and FPC (2.5.1) might also be a solution.
Several things have changed:
last month sb started working on the converters (Juha)
FPC 2.4+ bring the resource handling closer to Delphi (no more .lrs)
We recently converted our long-running Delphi project to Open Source. Multiple people have contributed patches already, which is great, but unfortunately forms and frames when saved with Delphi 2006 (and later) contain new properties in the .dfm that are not handled by older versions. Forms are handled quite gracefully by the IDE ("ignore propery?"), but frames are loaded at runtime and result in errors. Not an option, as far as I'm concerned.
I now removed those properties from the .dmf files by hand, but I am really wondering if there is a more elegant solution. There is no way to save in a backwards compatible format from the new IDE's, is there? Are there existing tools to strip the nonsupported properties from the .dfm's ? Any other elegant solution I am missing?
Normally, with a commercial project, I'd just upgrade the project to the most recent version applicable... but as this is open source I really don't want to loose out on those developers still working on Delphi 7. That includes myself, actually.
The JEDI JVCL project uses a little utility dc.exe (delphi cleaner) and a list of properties in DFMs that are not present in older versions of delphi, mine contains the following text:
*.PopupMode
*.PopupParent
*.ExplicitLeft
*.ExplicitTop
*.ExplicitWidth
*.ExplicitHeight
*.BevelKind
*.BufferDocument
*.DoubleBuffered
*.ParentDoubleBuffered
*.DisableHyperlinks
*.AlwaysEnquoteFloats
*.PixelsPerInch
I run this dc.exe utility from a batch file which cleans my dfms before I commit
changes to subversion. The syntax in my batch file for this is:
dc.exe -s -fd10.txt *.dfm -i
You can grab my stuff at:
http://sites.google.com/site/warrenpostma/files
You can try Andy's DFMCheck. It can automatically open and close all forms and frames in a project, which makes the IDE remove unknown properties (as Marco wrote).
Well, for sake of completeness:
Open the dfms in the oldest Delphi supported, let it remove all unknown properties, change a property and save.
For your purposes, Warren's solution is better, but it can be a workaround. I did it for a while when we were dual D7-D2006ing.
I am looking to add the capability for users to write plugins to the program I have developed in Delphi. The program is a single executable with no DLLs used.
This would allow the user community to write extensions to my program to access the internal data and add capabilities that they may find useful.
I've seen the post at: Suggestions for Adding Plugin Capability? but its answers don't seem transferrable to a Delphi program.
I would like, if possible, to add this capability and keep my application as a single executable without any DLLs or additional modules required.
Do you know of any resources, components or articles that would suggest how to best do this in Delphi, or do you have your own recommendation?
The first question I would ask is, do you need the plugins to access the UI of your host application, or add any UI elements of their own? Or will the plugins be limited to querying and/or supplying data to your host app?
The latter is much easier and opens up two possibilities. Others have already mentioned DLLs, which is the first way to go. Certain caveats apply - in general you should be interfacing with a dll using only the data types that are used in Windows API. THat way you can be sure that the plugin DLLs will understand your data types, no matter what language/compiler they were created in. (So for example, use PChars, not strings. Do not as a rule pass Delphi classes such as TStream to a DLL. This will appear to work in some cases, but is unsafe in general, because even if the DLL was compiled in Delphi, it may have been a different version of the compiler, with a slightly different idea of what TStream is). Google for using DLLs in Delphi, and you'll find plenty more tips.
Another way that hasn't been mentioned yet is to enable scripting in your application itself. There are several very capable 3rd-party scripting engines, both commercial and free, and most of them allow you to exchange Delphi objects with the script. Some of these libraries support only Pascal as the scripting language, others will let you use Basic (perhaps better for beginner users) or other languages. See for example RemObjects Pascal Script (free) at http://www.remobjects.com/free.aspx .
My favorite scripting solution at the moment is Python for Delphi (P4D, also free) from http://mmm-experts.com/Products.aspx?ProductID=3 It can interface beautifully with your classes via RTTI, and allows you to execute Python code in your Delphi app, as well as use Delphi classes in Python scripts. Given the popularity of Python, this may be a viable solution if you want to attract developers to your project. However, every user will need to have a Python distribution installed.
It seems to me that the barrier to entry, from the point of view of potential plugin writers, is lower if you use scripting than if you choose DLLs.
Now, back to my initial question: things get much more complicated if you need the plugins to interact with your user interface, e.g. by placing controls on it. In general, DLLs cannot be used to do this. The Borland/CodeGear-sanctioned way is to use packages (BPLs). With BPLs, you can access and instantiate classes offered by a plugin as if they were declared in your host application. The catch is, all BPLs must be compiled with the same exact version and build of Delphi that your main application is. In my opinion this makes packages completely impractical, since it's hard to expect that all the potential plugin writers around the world will be using the same version of Delphi you are. A major pitfall.
To get around this, I have experimented with a different approach: keep using DLLs, and develop a syntax for the plugin to describe the UI it needs, then create the UI yourself in the host app. (XML is a convenient way to express the UI, since you get the concept of parenting / nesting for free.) The UI description syntax can include callbacks to the DLL triggered when the contents or state of the control changes. This method will restrict plugins to the set of VCL controls your application already uses or has registered, though. And it's not a one-nighter job, while BPLs certainly are.
Google for "Delphi plugin framework", too. There are some ready-made solutions, but as far as I know they usually use BPLs, with their limited usefulness.
Actually, the accepted answer to the question you cite is quite appropriate for Delphi as well. Your plug-ins will be DLLs, and you can dictate that they should export a function with a certain name and signature. Then, your program will load the DLL (with LoadLibrary) and get the address of the function (with GetProcAddress). If the DLL doesn't load, or the function isn't there, then the DLL is not a plug-in for your application.
After you have the address for the DLL, you can call it. You can pass the function an interface to something that represents the parts of your application that you wish to expose. You can also require that the function return an interface with methods that your application will call at various times.
When testing your plug-in system, it will be wise to write a plug-in yourself with a language other than Delphi. That way, you can be more confident that you haven't inadvertently required everyone to use Delphi.
At first I went for BPL and DLL base plugins. And found them hard to mantain.
If you use BPL system, then you need to match BPL version with EXE version. This includes Delphi updates which can break something. I found out (the hard way) that if I need to include all my plugins with every release, there is no point in having plugins at all.
Then I switched to plain DLL plugins. But that system just complicated code base. And that's not a good thing.
While crusing the net I found out Lua embedded script language, and delivered with it. Lua is 150K DLL, embedding bytecode compiler, interpreter and very simple and smart dynamic programing language.
My plugins are simple lua scripts. Easily mantaind and made. There are premade Delphi examples, so you can export any class or procedure as Lua table or function. GUI or not. For example I had TurboPower Abbrevia in my app for zipping. I exported my zipping class to lua, and all plugins now can call zip('.', 'dir.zip') and unzip(). Then I switched to 7zip and only implemented old class to use 7zip. All plugins work as they did, with support for new zip('.', 'dir.7z').
I made TLuaAction which calls Execute(), Update(), Hint() procedure from its script.
Lua allso have it's own plugin system that makes it easy to add funcionality to it. Eg luacom make is easy to use COM automation, luainterface allows calling .net from lua.
See luaforge for more. There is Lua IDE made in Delphi, with source.
I tried to make an overview of all such options some time ago. Together with my readers/commenters we built this list:
DLL/BPL loaded from the program.
DLL/BPL loaded from a sandbox (which could be another copy of the program or a specialized "server" application and which communicates with the main program via messages/sockets/msmq/named pipes/mailslots/memory mapped files).
COM (in any of its variants).
DDE (please not).
External program that communicates via stanard input/output.
External program that communicates via files (file name is a parameter to the program).
External program that works via drop folder (useful for batch processing).
External program that communicates with windows messages/windows sockets/msmq/named pipes/mailslots/memory mapped files/database publish-subscribe.
The most universal method of adding plug-in capability is to use COM. A good book to get you started on the road is Delphi Com Programming by Eric Harmon. While it was originally written for Delphi versions 3 through 5, the books contents are still valid with the latest versions of Delphi.
Personally, I have used this technique along with active scripting to allow end user customization.
I'm using plug-ins to implement most of the functionality in the game engine I'm building. The main EXE is made up of a script engine, a plug-in manager, some basic graphics routines and not much else. I'm using TJvPluginManager from the JEDI VCL library. It's a very good manager, and it can add just about anything you want to your program. Check out the demos included with the package to see how it works. The only downside is that it adds a lot of JCL/JVCL code to your program, but that's not really an issue if you're already using other JVCL components.
If plugins will be developed in Delphi or C++ builder, use packages + interfaces. Delphi OTA is a good example for that.
If plugins will be language independent, COM is a good way to go.
Addition: If you won't use COM, u may need to provide SDKs for each language. And datatype handling between different languages can be pain(for example delphi string type). Delphi COM support is excellent, u don't need to worry about kind of details. Those are mostly impilicit with Delphi COM support. Don't try to invent the wheel again. I'm surprised why people doesn't tend to mention about it.
I found an article by Tim Sullivan:
Implementing Plug-Ins for Your Delphi Applications
You could have a look at Hydra from Remobjects. Not only will this allow you to add plugins, but also to mix win32 and .net.
I have developed about 300 Applications which I would like to provide with multi-language capabilities independent from the Operating System. I have written a just-in-time translator, but that is too slow in applications with many components. What would you suggest I do?
We are using TsiLang and are very happy with it.
One of the best points is that you can pretranslate the project with a dictionary (which you filled from existing translations).
I've heard that the TsiLang components are nice, but your looking at an inplace solution...
I've used GNU gettext for Delphi which does exactly the thing you want, it loads the translations from a text file and replaces the text in your components. It even has a pas/dfm scanner to automatically generate the English translation file.
It's also possible to automatically change your pascal source code to inject the gettext procedure inplace of your static strings. If I'm not mistaken it just adds a underscore as function to it, as below.
ShowMessage('Hello'); // before
ShowMessage(_('Hello')); // after
I must say it has been 2 years since I last used this method.
One thing will remain problematic, the Delphi components are not unicode enabled (D2009 fixes this), so when you don't change the components you'll still have limited support for other languages.
A good free solution would be GNU gettext for Delphi. It has some capabilities not present in TsiLang - for example, you can put the knowledge on how to count things (different endings for one, two, four, hundred and two, many ...) into the translation file so that you don't have to teach each program to know this stuff.
License for the Delphi part is very permissive but I'm not sure how much the included GNU stuff will affect your application.
Get Multilizer. It is made in Delphi and it can handle Delphi programs like no other with special support for VCL. You can even redo your screens easy for every language. With Multilizer you can use different techniques to translate and run your program.
Delphi 2009 has added an Integrated Translation Environment/External Translation Manager
ITE and ETM are now available for both Delphi and C++Builder.
In Codegear's article: What's New in Delphi and C++Builder 2009, they state:
The Integrated Translation Environment
(ITE) is a part of the IDE that
simplifies localizing your projects.
ITE can create a new localized project
from an existing project. ITE does not
automatically translate text, but
provides a dialog listing all text
that needs to be localized and fields
in which to enter the corresponding
translated text. Once you have entered
the translated text and built the
localized project, you can set another
language active and display a form in
the localized text; you don't have to
switch locales and reboot your system.
This allows you to perform
localization without requiring a
localized system.
The External Translation Manager (ETM)
is a standalone application that works
with DFM files and text strings in the
source code. Although ETM does not
allow you to create a new localized
project, it does provide a dialog
listing localized text and the
translated text, similarly to ITE.
This is what I plan to try first once I am at the point that I want to Internationalize my product.
However, to me the easy part is to translate the program. The hard part is to translate the help file.
I would say GNU gettext for Delphi in combination with TMS Unicode Component Pack (previously free under TntWare) to get unicode support in the components.
To work with, or have translators work with, the gettext files I recommend looking at the free cross-platform Poedit that may edit the .po files.
Just to mention cxLocalizer if you own DexExpress components.