Office.Cloud.Microsoft.Tasks

About

The SequenceGenerator updates Bushiness Objects members with unique sequential values.

Installation

1. First you need the nuget package so issue this command to the VS Nuget package console

   Install-Package Xpand.XAF.Modules.SequenceGenerator.

   The above only references the dependencies and nexts steps are mandatory.

2. Ways to Register a Module or simply add the next call to your module constructor

   RequiredModuleTypes.Add(typeof(Xpand.XAF.Modules.SequenceGeneratorModule));

Versioning

The module is not bound to DevExpress versioning, which means you can use the latest version with your old DevExpress projects Read more.

The module follows the Nuget Version Basics.

Dependencies

.NetFramework: net461

DevExpress.Persistent.Base	Any
DevExpress.ExpressApp	Any
DevExpress.ExpressApp.Validation	Any
DevExpress.ExpressApp.Xpo	Any
Fasterflect.Xpand	2.0.7
JetBrains.Annotations	2019.1.3
System.Reactive	4.3.2
Xpand.Extensions	2.201.28
Xpand.Extensions.Reactive	2.201.28
Xpand.Extensions.XAF	2.201.28
Xpand.Extensions.XAF.Xpo	2.201.28
Xpand.XAF.Modules.Reactive	2.201.28
Xpand.VersionConverter	2.201.7

Issues-Debugging-Troubleshooting

To Step in the source code you need to enable Source Server support in your Visual Studio/Tools/Options/Debugging/Enable Source Server Support. See also How to boost your DevExpress Debugging Experience.

If the package is installed in a way that you do not have access to uninstall it, then you can unload it with the next call at the constructor of your module.

Xpand.XAF.Modules.Reactive.ReactiveModuleBase.Unload(typeof(Xpand.XAF.Modules.SequenceGenerator.SequenceGeneratorModule))

Details

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Credits: to Brokero that sponsor the initial implementation of this module.

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The SequenceGenerator module is a well tested implementation variation of the E2829. The module can be configure to generate unique numerical sequences per ObjectType/memberName combination.

In details: when any XAF database transaction starts an Explicit UnitOfWork is used to acquire a lock to the SequenceStorage table. If the table is already locked the it retries until success, if not it queries the table for all the object types that match the objects inside the transaction and assigns their binding members (e.g. a long SequenceNumber member). After the XAF transaction completes with success or with a failure the database lock is released. A long sequential number is generated only one time for new objects.

Configuration

You can configure the Sequence binding at runtime by creating instances of the SequenceStorage BO as shown in the next screencast.

The SequenceStorage table is a normal XAF BO, therefore it is possible to create sequence bindings in code by creating instances of that object. However we do not recommend creating instances directly but use the provided API (possibly in a ModuleUpdater). The API respects additional constrains and validations.

To generate the configuration of the screencast you can use the next snippet.

objectSpace.SetSequence<Order>(order => order.OrderID,2000);
objectSpace.SetSequence<Accessory>(accessory => accessory.AccesoryID,1000);

To share the same sequence between types use the SequenceStorage.CustomType member.

To observe the generation results you may use a call like the next one:

SequenceGeneratorService.Sequence.OfType<Order>()
.Do(DoWithOrder)
.Subscribe();

SequenceGeneratorService.Sequence.OfType<Accessory>()
.Do(DoWithAccessory)
.Subscribe();

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Limitations:

The module works only for MSSQL, MySql, and Oracle databases.

Possible future improvements:

1. Provide logic to allow re-generation of a sequence for e.g. when an object is deleted or per demand.
2. Support all database providers.
3. Additional constrains e.g. based on view, on model, on object state etc.

Let us know if you want us to implement them for you, or if you have other ideas and needs.

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Tests

The module is tested on Azure for each build with these tests