Validating Receipts of Mac App Store Purchases including In-App Purchases

For next prerelease we have something new.
We add three new classes: AppReceiptMBS, AppReceiptIAPMBS and AppReceiptVerificatorMBS.

The AppReceiptMBS class allows you to load the receipt from within your own app or from a given file. You can query identifier, app versions, various dates like purchase date or expiration date. Using the AppReceiptIAPMBS class we provide an array of the in-app purchases. For each in-app purchase you can query details like product identifier, purchase or cancellation dates, quantity or the transaction identifier.

Our AppReceiptVerificatorMBS class can verify if app receipt is valid. Either you pass in a receipt, bundle identifier and app version to check if some receipt file is valid for a given app. Or you just ask if the application's own receipt is valid.

We hope this helps Xojo developers using the Mac App Store. As we also have the whole StoreKit framework covered from Apple, you can use the MBS Plugins for a complete In-App Purchase solution.

Plugin will be available soon as part of pr8 or if you like to try it on the weekend, I could email you a copy.

Research Triange Park Group Meeting

we just go notice about a Xojo developer meeting in North Carolina, USA:

Are you in the RTP, North Carolina area? Join @Patrick McCabe and other Xojo devs at the next meeting, 7PM September 8th 2014 at Rally Point Sports Grill!

Jay is going to give a short explanation and demo of Database's in Xojo.

Address for Meeting:
Rally Point Sports Grill
1837 N. Harrison Ave
Cary, NC 27513
(919) 678-1088

It is located right off Interstate 40, in the shopping center across from SAS. They have a private room which is reserved for the group, the room is located to the left when you enter the restaurant.

Join the group for updates on all meetings:!forum/rtpnc-xojo-usergroup

MBS Xojo Developer Conference in three weeks

Just three weeks left until the conference starts. If you like to attend, please register soon. We already have participants from 10 countries and the hotel will soon run out of available rooms.

Stéphane Pinel will be present and talk about this topics:

  • What happened in 2014
  • Xojo 2014r3, the iOS take off
  • Works in progress
  • What's next?
  • Q&A
Xojo for iOS in deep
  • iOS support in the IDE
  • Introducing the new Xojo Framework
  • Extending iOS support using Declares
Social networks from Xojo
  • When/Why using social networks from your apps?
  • How to do it?
  • Live examples with Twitter & Facebook
The dates:
17th - Xojo Training in German
18th and 19th - MBS Xojo Conference in English
20th - Xojo Training in English

Tip of the day: Weak Property pattern

Often we have to keep properties with references to other objects, but want to avoid circle references causing memory leaks. So we have to have a clear reference tree from root object to child objects. If we want a reference from child back to parent, we need to use a weak reference.

Other use is if you have two windows where one window needs to reference other, but one of the windows should be able to get away without leaving a reference to a dead window. Sometimes we have trouble as a window was closed already, but we have a reference to it. Accessing it causes an exception as controls are dead already.

So how to make a weak property?

First you create the normal property, e.g. test as window. Next you select it to convert it to computed property. The private property created by Xojo now changes type to WeakRef. The setter changes to this:

Sub Set() if value = nil then mTest = nil else mTest = new WeakRef(value) end if End

As you see we now create a weak Reference for the given value. If value is nil, we don't need the weak reference, so we set to nil.
For the getter, we simply take the value from WeakRef the value and return it. We use a variant for easy casting:

Sub Get() if mTest <>Nil then dim v as Variant = mTest.Value return v end if End

The property can now be used like other properties. You don't really notice it is using a weak reference. Just you have to prepare for the case the property is suddenly nil.

MBS Xojo / Real Studio Plugins, version 14.3pr7

New in this prerelease of the 14.3 plugins:
  • Added JPEGData and PNGData to CGImageMBS class.
  • Added MemoryBlock.ConvertRGB12BitTo8BitMBS.
  • Added PDFDocumentMBS.appendPage.
  • Fixed JSONMBS.Constructor. Now creates an empty JSON object. If you need an array node, please use JSONMBS.NewArray.
  • Added containerURLForSecurityApplicationGroupIdentifier and containerFolderForSecurityApplicationGroupIdentifier to NSFileManagerMBS class.
  • Added WindowsTimerMBS class for high resolution timers.
  • Fixed AUPlayerMBS.Pan for older Mac OS X.
  • Added AUPlayerMBS.UseNewTimePitchUnit property.
  • JSONMBS now passes through \u0000 as it can't handle chr(0) in a string.
  • Added JSONMBS.ToString as property.
  • Added DragItem.NSDraggingInfoMBS function.
  • Improved NSDraggingInfoMBS class.
  • Changed NSScrollViewMBS to have properties visible in debugger.
Download: Or ask us to be added to our shared Dropbox folder.

PS: In newer plugins, the WindowsTimerMBS class got renamed to TimerMBS.

New Timer for Windows

If you use a normal Xojo Timer in your project, you can use periods down to around 16 ms. Even if you select 5 ms, you get about 16 ms. More than 60 action events per second are not possible. See this test project which measures what we get for a timer with 5 microseconds:

Now with next MBS Plugins, we have already prepared a replacement class: WindowsTimerMBS.
This class can provide an action event on main thread much closer to the 5 ms target as you see in this screenshot:

Of course timer can only fire if main thread is not busy, so if you do too much code in action event, the next event may be delayed.
I hope this makes a couple of Xojo developers happy, for example if you want to measure values 100 times per second on a serial port.

PS: In newer plugins, the WindowsTimerMBS class got renamed to TimerMBS.

MBS Xojo Developer Conference in 4 weeks

Just four weeks left until the conference starts. If you like to attend, please register soon. We already have participants from 10 countries and the hotel will soon run out of available rooms.

We still have seats available for training in English and German.

Recently we added a new session about Extending the Framework from Tobias Bussmann. He will also show their huge web app for the Swiss Academy of Sciences made with Xojo.
Finally a few days ago we added a session be Valdemar de Sousa about In-App Purchases in the Mac App Store.

Hotel in Koblenz is reserved for 17th to 20th September 2014.

17th - Xojo Training in German
18th and 19th - MBS Xojo Conference in English
20th - Xojo Training in English

Tip of the day: Autohide scrollbar

If you put this code in a textarea's open event, you get a modern small auto hiding scroll bar:

dim n as NSScrollViewMBS = me.NSScrollViewMBS n.scrollerStyle = NSScrollerMBS.NSScrollerStyleOverlay n.verticalScroller.controlSize = NSScrollerMBS.NSSmallControlSize n.verticalScroller.knobStyle = NSScrollerMBS.NSScrollerKnobStyleDark n.scrollerKnobStyle = NSScrollerMBS.NSScrollerKnobStyleDark n.verticalScroller.scrollerStyle = NSScrollerMBS.NSScrollerStyleOverlay

As you see plugin provides for a lot of framework classes a function to quickly get the plugin counterpart. For Textarea, we provide quick access to NSTextViewMBS and NSScrollViewMBS objects. And on the scrollview the plugin provides all the accessors and constants to do this.

MBS Xojo / Real Studio Plugins, version 14.3pr6

New in this prerelease of the 14.3 plugins:
  • Added XML parameter for WinSpeechMBS class, so text can embed xml commands to control voice.
  • Fixed a bug with PictureMBS, clipping and VM mapped files.
  • Added Audioformat parameter to SpeakFile method in WinSpeechMBS class.
  • Added SQLAnywherePreparedStatementMBS.kTypeNull and SQLPreparedStatementMBS.kTypeNull.
  • Changed SQL Plugin to raise UnsupportedOperationException if you call SQLDatabaseMBS TableSchema or FieldSchema functions.
  • Changed SQL Plugin to raise UnsupportedOperationException if you call update, edit, delete or deleteAll methods on a RecordSet.
  • Added FileListMBS class constructor parameters to filter items on Windows.
Download: Or ask us to be added to our shared Dropbox folder.

Tip of the day: Windows Notifications

In 2012 we added to our plugins a WinNotificationMBS class. This class was designed to send and receive broadcast messages on Windows between running apps. This way a helper app can send status updates easily to main app. Without the need to setup IPCSocket or other ways of communication.

Now Windows also sends a couple of messages to everyone about certain things. Like you can get a WM_DISPLAYCHANGE message whenever the display setup changed. Also the WM_DEVICECHANGE message informs about devices coming and going.

To use this, get a subclass of WinNotificationMBS and add the GotNotification event. Now listen for messages WM_DISPLAYCHANGE (&h7E) and WM_DEVICECHANGE (&h0219). The event will be called with those message codes so you can check state and update your app.

PS: On Mac you can also get similar events with NSWorkSpaceMBS and NSNotificationObserverMBS.

Xojo 2014r2.1

A few days ago Xojo 2014r2.1 was released. This is the final release to support Carbon as Cocoa will be the only option from 2014r3 on forward. So we are happy that the XmlDocument bugs have been fixed for Carbon target. Any other Carbon bug will probably never be fixed in the future.

For the Webkit support on Windows, Xojo went back from CEF3 to CEF1 version. The newer version had some side effects which made the older version a better choice. For our plugin, well the 14.2 plugins assume that 2014.2 uses CEF3. With 14.3 we put in an auto detect feature, so plugin can see what version of CEF is used and either use the CEF1 or the CEF3 API. So in case you use the Chromium classes from our plugins, be careful.

Database classes got some updates on MySQL, ODBC and SQLite. Like better full text search with unicode support for SQLite.

For Mac App Store the RegEx plugin was fixed, so you can submit again apps using it. See older blog post.

Please also check the blog post about the HandleSpecialURL change in this release.

For the last days, we have been using this version and it's quite stable for our projects here. So we can recommend the update.

MBS Xojo / Real Studio Plugins, version 14.3pr5

New in this prerelease of the 14.3 plugins:
  • Rewrote CPUID detection. Added new methods to CPUIDMBS class.
  • Updated DynaPDF to version
  • Made first changes for future Mac OS X version.
  • Added AUPlayerMBS.Reset.
  • Fixed bug with DataMatrix encoding in barcode generation.
  • Updated zint library to current version.
  • Updated to Portaudio v19 20140130.
  • Updated to OpenSSL 1.0.1i.
  • Fixed problem with NSRunningApplicationMBS objects in dictionaries.
  • Added options for SQLConnectionMBS and SQLDatabase to turn on SSL for MySQL via new options: MYSQL_SSL_KEY, MYSQL_SSL_CERT, MYSQL_SSL_CA, MYSQL_SSL_CAPATH and MYSQL_SSL_CIPHER. If those are set, we pass the strings to mysql_ssl_set function.
  • Added ConnectionHandler event to SQLConnectionMBS and SQLDatabase classes.
  • Fixed GKTurnBasedParticipantMBS.matchOutcome property to be writable.
Download: Or ask us to be added to our shared Dropbox folder.

MBS Xojo / Real Studio Plugins, version 14.3pr4

New in this prerelease of the 14.3 plugins:
  • Updated LCMS2 to latest 2.7beta0 from 3rd August 2014.
  • Updated LCMS2 used for GraphicsMagick to version 2.6.
  • Fixed issue with NSFileHandlerMBS object and NSNotificationMBS.
  • Improved NSPopupButtonMBS class with more properties.
  • Changed GMImageMBS.SetImageMask to turn set matte = true to make sure we have an alpha channel.
  • Fixed bug with internal NSObject to Variant conversion.
Download: Or ask us to be added to our shared Dropbox folder.

MBS Xojo Developer Conference

The early bird offer will end 11th August and that is also the end date for the hotel contingent. Please register quickly to make sure you get a room in the hotel.
Also we still have seats available for english and german training.

Hotel in Koblenz is reserved for 17th to 20th September 2014.

17th - training in German
18th and 19th - conference in English
20th - training in English
The biggest plugin in space...


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