I don't understand LiveBinding's purpose. I would like to know which are the cases in which LiveBinding is most valuable. Embarcadero's manual describes it: "LiveBindings is a data-binding feature supported by both the VCL and FireMonkey frameworks in RAD Studio. LiveBindings is an expression-based framework, which means it uses binding expressions to bind objects to other objects or to dataset fields".
Thanks but I still don't know more than before.
I have seen some video in which a guy spends 12 minutes and hundredths of clicks to connect the caption of a TLabel to a TListBox control. When the user clicks an item in ListBox the name of the item is shown in Label. I could have done that with a single line of code (few keystrokes and no mouse clicks).
I am not criticizing LiveBinding. I am saying that I don't understand where it is helpful. I am missing something. Since it is not doing something that cannot be done from code, it means it's doing something that can be done from code, but visually and much much faster. I admit I haven't invested a lot of time in this topic but everywhere I look I see a terribly convoluted way (come on, you really need 5 extra controls to make LiveBinding works?) to do a simple task.
Also, it seems that LiveBinding was mostly designed for DB. All examples will include some kind of DB connectivity. But I am expressly interested only about the cases where I can use LiveBindings and there is no data set/DB involved. I am not using DB that much.
I doubt v. much that anyone would use live bindings if they could use traditional db-aware VCL components. However, that's not an option for non-VCL projects (Android, Apple, etc) and live bindings is the only Emba-supplied option for delivering data to those from TDataSet descendants.
An advantage of live bindings is that in addition to the Android and Apple targets, you can use them in Windows apps, so conceivably you could write the same (FMX-based) application for all three.
Libe-binding can also be used in VCL applications, but tbh, I can't imagine why anyone would use live bindings if they were only targeting a Windows DB application, as they are much slower than the traditional db-aware controls, especially multi-row ones such as grids.
I have not tried myself, but because the implementation of live bindings is interface-based, its potential use extends far beyond DB applications, but you would have to implement the interfaces yourself. It seems to be based around a fairly abstract expression-evaluation engine.
Setting up a l.b. project in the IDE does seem to require quite a bit more clicking around than you'd be used to from a traditional VCL app, but that's mostly because there is an additional step involved where you tell the IDE how to bind the gui objects to the data source(s). However, it is quite straightforward to "wire up" live bindings entirely in code if you want to.
Related
Heading : How can I read a StringGrid content in another application's window?
I could get the StringGrid's handle
A Delphi string grid is a pure VCL control. You cannot use windows messages to read its content. You cannot use any of the automation APIs because Embarcadero do not and have never made their controls accessible. For which, incidentally, shame on them.
The only viable way to do this is through gross hacking. If you know the memory layout of the control you can read its memory the same way as a debugger does. Using calls to ReadProcessMemory. However, this will be exceptionally messy and hard to achieve.
A simple approach would be to inject a DLL into the target process. So long as your DLL is built with the same version of Delphi as the target process, there's a reasonable chance that you'll be able to read out the contents of the grid. You can then use IPC to send the information back to the other program.
Note that none of these solutions are remotely appealing. If you can find a cleaner way to do this, possibly avoiding this target process altogether, then you should give it strong consideration.
Although it is comparatively hard to write in C++ than in Pascal I'm really attracted by multi-platform support of Qt. I can connect to an MSSQL server running on Win2003 server from Linux or I can connect to a PostGreSQL server running on Linux. That made a plus when comparing with Delphi.
I'm trying to write sample programs to get used to the Qt and C++. So far I'm comfortable with the layouts and signals-and-slots mechanism (still double clicking the buttons to write event code though :) ). I wish I was using the SQL data in my programs as easily as in Delphi.
Is there any way that I can put some connection object, a DataSource, a DBGrid and a DBNavigator on to a form and go on without writing code? (For some forms it is really a time saver, a project with 300+ forms can be made faster)
I would like to hear from people using Qt with data from SQL servers.
You would have to write your own designer plugins to achieve that and make your widgets invisible, as there is no direct support for non gui components in Qt Designer.
However, writing explicit code in Qt (which is really a lot less work than in most other programming environments) helps the program to stay readable. Delphi projects with a lot of forms and components tend to become readable to the author alone, because dependencies jump across files a lot. If you store your forms in binary format, you are lost anyway, because you then cannot search your project textually to find dependencies.
Good design, which causes your code to become small and easily readable is necessary in any programming environment and makes aspects like invisible components in forms less important (though you will miss them for a while to come like I do).
So, unfortunately, you are on your own for the moment.
I've heard a lot about the new/improved RTTI capabilities of Delphi 2010, but I must admit my ignorance...I don't understand it. I know every version of Delphi has supported RTTI...and I know that RTTI (Runtime Type Information) allows me to access type information while my application is running.
But what exactly does that mean? Is Delphi 2010's RTTI support the same thing as reflection in .NET?
Could someone please explain why RTTI is useful? Pretend I'm your pointy haired boss and help me understand why RTTI is cool. How might I use it in a real-world application?
RTTI in Delphi is still not quite as full-featured as Reflection in .NET or other managed languages, because it is operating on compiled code, not an Intermediate Language (bytecode). However, it is a very similar concept, and the new RTTI system in Delphi 2010 brings it a lot closer to reflection, exposing an entire object-oriented API.
Pre-D2010, the RTTI was pretty limited. About the only thing I ever remember doing with it was converting an enumerated type to a string (or vice versa) for use in drop-down lists. I may have used it at one point for control persistence.
With the new RTTI in D2010 you can do a lot more things:
XML Serialization
Attribute-based metadata (TCustomAttribute). Typical use cases would be automatic validation of properties and automated permission checks, two things that you normally have to write a lot of code for.
Adding Active Scripting support (i.e. using the Windows script control)
Building a plug-in system; you could do this before, but there were a lot of headaches. I wasn't able to find a really good example of someone doing this from top to bottom, but all of the necessary functions are available now.
It looks like someone's even trying to implement Spring (DI framework) for Delphi 2010.
So it's definitely very useful, although I'm not sure how well you'd be able to explain it to a PHB; most of its usefulness is probably going to be realized through 3rd-party libraries and frameworks, much the same way it works in the .NET community today - it's rare to see reflection code sitting in the business logic, but a typical app will make use of several reflection-based components like an Object-Relational Mapper or IoC Container.
Have I answered the question?
D2010's extended RTTI is a lot like C#'s reflection. It gives you the ability to get at any field of an object, or inspect its methods. This has all sorts of potential uses. For example, if you can read any field of an object, you can write serialization code that can work with any object. And the ability to inspect methods and obtain their name and signature makes a class much easier to register with a scripting engine.
To me, that's the primary advantage of extended RTTI: The ability to write code that works with any class by examining its members, instead of writing different versions of the same code over and over, tailored to each individual class.
Most people probably won't use it in a real world application.
The people who will use it are the framework builders. Frameworks such as DUnit make extensive use of RTTI.
With the new RTTI capabilities we should expect to start seeing more advanced frameworks and tools appearing, similar to what is available for .NET. These frameworks will revolutionise your development moreso than RTTI will on it's own.
RTTI in Delphi has always been important since version 1.0. Classic RTTI features include the "published" properties section of Classes, which allowed the Object Inspector and the component designtime features to work. For my purposes, I would often use Published class properties to allow for enumeration of those properties at runtime. To store things from my objects to disk, for persistence.
The Delphi 2010 RTTI extends this classic RTTI massively, so much so that you could be forgiven for thinking Delphi did not even have RTTI until delphi 2010.
I would say the #1 most useful applications of "The New RTTI" are (as several other answers already state) going to be in Frameworks written by the gurus, that:
Handle persistence to files or databases. Database and configuration or document saving/loading frameworks and components would use this under the hood.
Handle pickling/marshalling/encoding/decoding to and from various
over-the-wire formats, like JSON, XML, EDI, and other things.
Unit testing was mentioned by someone else (JUnit), but I think perhaps the same frameworks could be really handy for debug and error reporting tools. Given an object passed as a parameter, on the stack, why not have bug reports that can dump all the data that was passed along to a function that failed, and not just a list of functions?
As you can see, some creative people are likely to think of even more uses for this. You could say, that though it does not bring parity to .NET reflection (which another answer speaks more about), it does bring a lot of "dynamic language" features (Think of Perl, Python, JavaScript) to an otherwise strongly typed static-type systems world of Delphi.
For me, personally, extended RTTI gave a possibility to retrieve calling convention from the method pointer. However, currently, that code is under conditional directive, because i am not satisfied with it.
(Critics and suggestions on workarond with basic RTTI are welcome, tho)
Look for TMS Aurelius and you will see that RTTI Attributes are very useful in terms of creating an ORM DataBase Framework and XML Serialization into pure objects and the opposite too.
You are supposed to care because they put it on the box. Clearly they think that some people will care.
Whether you actually have a use for it is entirely dependent on the nature of your projects. Since you didn't have it before and don't understand why having it now is a benefit, this would suggest to me that you don't have a use for it. It's then up to you whether to spend the time researching the subject further in order to discover whether you might be able to find a use for it.
Whether that is the most productive use of your time in relation to your projects, again is something only you can know.
I need to speed up my coding, too much work, so I need be able to generate code.
Any tools, any ideas?
Delphi includes Live Templates, a completely scriptable and configurable system for generating code constructs of any size or complexity.
Live Templates are, in my view, one of the more under-appreciated features in Delphi.
Find out how to use them at: http://delphi.wikia.com/wiki/Delphi_Live_Templates
and
http://delphi.wikia.com/wiki/Live_Templates_Technical_Info
Live templates are completely scriptable, meaning you can write Delphi code to do whatever you want with them.
An extendable example can be found here:
http://cc.codegear.com/Item/26420
Not a very good idea IMHO. If you need generator, then probably you have lots of code that looks very similar, so instead of generator, better thing would be to rethink and refactor code you have.
That should result in less code that is easier to maintain and less code in future for similar tasks.
If you are doing database application, then you could use some good visual SQL query builder to help you create queries. That is part that Delphi was not very good (I don't know if it improved in D2007 and D2009)
EDIT - Regarding SQL generation
There's lots of comments about query builder.
Well, I suppose I'm spoiled. As I remember, Delphi before version 6 (or maybe even 5?), had decent visual query builder. I had 0 (zero) bugs in SQL when I selected fields in query designer, opposed to writing SQL by myself.
SQL is just string in Delphi, there is no compiler checking, so this was the best way to ensure that SQL is correctly written.
If you mean something like a modeling tool, you could try out ModelMaker.
Rather than trying to code generate, you should probably just obtain code to do the bulk of what you want to do.
There are hundreds of free products at Sourceforge for Delphi.
And there are hundreds of thousands of code samples at Google Code Search that you can use.
Plus lots thousands of free or purchaseable components at repositories such as Torry's Delphi Pages or Embarcadero's Code Central for Delphi
Using components already made is the fastest way to speed up your coding, and to add capabilities that you would never have been able to.
For me best way is by creating custom components, and then create designer for this component.
I have find that i spent most of the time writing code that read/write values from controls. So i created control that can read, write, validate values, and automatically fill form or stored procedure or directly generate SQL and execute.
Custom designer allows you to setup all properties easy. Now i don't write code for such trivial task i just put control , open designer and set properties and rules that must be satisfied.
ModelMaker Code Explorer speed up my coding in times. It has a nice hotkeys for synchronising implementation and declaration, so if you changed one, you don't have to search for it pair. Also, very nice feature is, method editing dialog. And many more.
Have you tried GExpert? It is a set of tools built to increase the productivity of Delphi and C++Builder programmers by adding several features to the IDE. GExperts is developed as Open Source software.
Other alternative is using project template by saving a framework into the IDE Repository, create your own components and frames.
I wrote a code generator calle CodeTypo. I'm used it in many production environment. You can find it here: http://dade2000.altervista.org/index.php?page=CodeTypo
It's still in beta phase but is usable and reasonably stable.
I'll migrate all content of this old site in the new one (www.danieleteti.it) in english. And I'll add some other info about CodeTypo and code generators.
The thing that sped up my Delphi coding the most was getting CodeRush for Delphi (via a DevExpress VCL subscription for Delphi 5, 6, 7) and setting up a ton of templates.
I am re-writing and/or consolidating a bunch of my "app framework" classes (basic mainform, about box, locking routines & purchase linking, auto-update, datamodule initializer, etc) -- Basically, I have a number of small potential shareware apps that I'm wanting to get out the door, and want to re-use code where I can, as well as build a framework for later apps to save time.
In one app I have auto-updating, I'm using LMD's WebUpdate, and am reasonably happy with it, but given that I'm re-vamping everything, I thought I'd see what the consensus is for "best approach" on this. I don't mind paying for commercial, nor using open source if that's best... just would rather not reinvent the wheel. (I've read: Delphi: How do you auto-update your applications?)
What is the best Auto-update component for Delphi Win 32 apps?
I use TmxWebUpdate. It's free, simple and easy to customize. I also own TMS Component Pack with TWebUpdate, but never really found a good incentive to switch.
I use TWebUpdate from TMS Components and am very happy with it. I haven't used LMD so unfortunately am not able to provide a comparison.
TMS also supply a whole raft of other components so if your re-writes require any else, especially if you want some shiny UI enhancements (TMS have a range of iPhone-style components) then the website is certainly worth a visit.
They seem fairly active in their support forums (although I haven't had need to use them for the WebUpdate component) and they have a fairly regular release cycle.
I have heard good compliment about TWebUpdate from Tmssoftware
also torry has much components for the same job, some are free and others are commericals.
Now what's the best?, it's depend on your needs, you already using one from LMD, which is a good company and I have very good experince with their components, but never used this one.
If you need a specific functionality, or you have some problems with the current one you are using, it's will be better to list them, so you will get a better answers, but it's hard to define the best, because every one has different experience and views.
I use TWebUpdate myself. It works, but the docs are a bit limited and it seems a bit buggy sometimes.
I have looked into LMD's (I have their full component pack), but it seemed to be much more limited than TWebupdate.
I'm also using TWebUpdate, and have to echo stg's comments on quality of support (good), and quality of documentation (spotty -- it's old, and doesn't always reflect their new features immediately).
You'll also find some places that stress the "roll your own" approach.
Remember that part of the auto-update issue is the tools that you will need to create the update "package" at your end. TMS Software makes a tool available for use with TWebUpdate, and it's reasonably well done. In my case, I'm "misusing" the component to deal with multiple files so that I can refresh additional related libraries, text files, etc. The update builder tool isn't really good for that. So there's some manual editing. But the updating part works well.
I'll also add a caution that you need to be careful with updates in Vista (and probably Windows 7). Writing to the protected places in the Program Files hierarchy was problematic for me. You may want to check that out with whatever component you use.
Have you considered Appwave from Embarcadero. It's not free and I don't know the price.