Synopse Open Source

2014-08-11

Cross-Platform mORMot Clients - Units and Platforms

By AB4327-GANDI, 2014-08-11. Open Source › mORMot Framework

Current version of the main framework units target only Win32 and Win64 systems.

It allows to make easy self-hosting of mORMot servers for local business applications in any corporation, or pay cheap hosting in the Cloud, since mORMot CPU and RAM expectations are much lower than a regular IIS-WCF-MSSQL-.Net stack.
But in a Service-Oriented Architecture (SOA), you would probably need to create clients for platforms outside the Windows world, especially mobile devices.

A set of cross-platform client units is therefore available in the CrossPlatform sub-folder of the source code repository. It allows writing any client in modern object pascal language, for:

Any version of Delphi, on any platform (Mac OSX, or any mobile supported devices);
FreePascal Compiler 2.7.1;
Smart Mobile Studio 2.1, to create AJAX or mobile applications (via PhoneGap, if needed).

This series of articles will introduce you to mORMot's Cross-Platform abilities:

Any feedback is welcome in our forum, as usual!

2014-08-05

Returning content as XML

By AB4327-GANDI, 2014-08-05. Open Source › mORMot Framework

By default, interface-based services of a mORMot server will always return a JSON array (or a JSON object, if TServiceFactoryServer.ResultAsJSONObject is true).
With some kind of clients (e.g. if they are made by a third party), it could be useful to return XML content instead.

Your mORMot server is able to let its interface-based services return XML context instead, or in addition to the default JSON format.

2014-07-12

Static class variables are just global variables in disguise

By AB4327-GANDI, 2014-07-12. Pascal Programming

Cape Cod Gunny just wrote a blog article about how to replace a global variable by a static class instance.

But I had to react!
Using such static declaration is just another way of creating a global variable.
This is just a global variable in disguise.
In fact, the generated asm will be just like a global variable!

It encapsulates the global declaration within a class name space, but it is still IMHO a very wrong design.
I've seen so many C# or Java code which used such a pattern (there is no global variable in those languages), and it has the same disadvantages as global variables.
Just like the singleton syndrome,
Code is just not re-entrant nor thread-safe.
Nightmare to debug and let evolve.

2014-07-04

Website of the day

By AB4327-GANDI, 2014-07-04. Open Source

Just wanted to share some awesome SOA revolutionary idea, on 4th of July... You should take a look at http://devnull-as-a-service.com ! DAAS rocks! We will write certainly a native mORMot provider for this great data provider. This is another great Open Source project (full code is included).

2014-06-30

Sub-optimized Win64 Delphi compiler: missing branch table for case of

By AB4327-GANDI, 2014-06-30. Pascal Programming

As we already stated here, the Delphi compiler for the Win64 target performs well, as soon as you by-pass the RTL and its sub-optimized implementation - as we do for mORMot.
In fact, our huge set of regression tests perform only 10% slower on Win64, when compared to Win32.
But we got access to much more memory - which is not a huge gain for a mORMot server, which uses very little of RAM - so may be useful in some cases, when you need a lot of structures to be loaded in your RAM.

Slowdown on Win64 is mostly due to biggest pointer size, which will use twice the memory, hence may generate a larger number of cache misses (failed attempts to read or write a piece of data in the cache, which results in a main memory access with much longer latency).
But in Delphi, apart from the RTL which may need more tuning about performance (but seems not to be a priority on Embarcadero side), is also sometimes less efficient when generating the code.
For instance, sounds like if case ... of ... end statements do not generated branch table instructions on Win64, whereas it does for Win32 - and FPC does for any x64 platform it supports.

2014-06-27

RoadMap refreshed

By AB4327-GANDI, 2014-06-27. Open Source › mORMot Framework

We did some cleaning in the mORMot official RoadMap.
Now feature requests tickets will detail all to-do items we would like to implement.

Current framework RoadMap and implementation is in fact going into a pragmatic direction.
No need to make all framework's unit compatible at once: so we introduced some client-dedicated units, without any dependency on SynCommons.pas.

We would like to implement (in this order):

Cross-platform clients (Delphi FMX, SmartMobileStudio, FPC) [09ae8513eb] [168eb753e5] [d7e5521da5];
MVC web support [bd94c11ab1];
Cross-platform server via FPC [3a79adc10f];
Event-driven features [aa230e5299].

The CrossPlatform folder already contains units which compile under all Delphi compilers (VCL and FMX), and FPC.

But perhaps we would move the server to Linux, either via FPC, or using Delphi itself!

Tip about Fossil ticket reports

By AB4327-GANDI, 2014-06-27. Open Source

It appears that version 1.25 of Fossil did change the ticket storage behavior:

Enhancements to ticket processing. There are now two tables: TICKET and TICKETCHNG. There is one row in TICKETCHNG for each ticket artifact. Fields from ticket artifacts go into either or both of TICKET and TICKETCHNG, whichever contain matching column names. Default ticket edit and viewing scripts are updated to use TICKETCHNG.

As stated by the official Fossil Change Log.

It appears that it just broke existing reports, so we had troubles with display of the ticket on our site.

Since we managed to find a workable solution, we would like to share it on our blog, to save other users time!

2014-06-22

Audit-trail for ORM change tracking

By AB4327-GANDI, 2014-06-22. Open Source › mORMot Framework

Since most CRUD operations are centered within the scope of our mORMot server, we implemented in the ORM an integrated mean of tracking changes (aka Audit Trail) of any TSQLRecord.
In short, our ORM is transformed into a time-machine, just like the good old DeLorean!

Keeping a track of the history of business objects is one very common need for software modeling, and a must-have for any accurate data modeling, like Domain-Driven Design.
By default, as expected by the OOP model, any change to an object will forget any previous state of this object. But thanks to mORMot's exclusive change-tracking feature, you can persist the history of your objects.

Enabling audit-trail

By default, change-tracking feature will be disabled, saving performance and disk use.
But you can enable change tracking for any class, by calling the following method, on server side:

 aServer.TrackChanges([TSQLInvoice]);

This single line will let aServer: TSQLRestServer monitor all CRUD operations, and store all changes of the TSQLInvoice table within a TSQLRecordHistory table.