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Where can I find document for how to implement the GenerateID() interface?

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davidklitzke View Drop Down
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Post Options Post Options   Quote davidklitzke Quote  Post ReplyReply Direct Link To This Post Topic: Where can I find document for how to implement the GenerateID() interface?
    Posted: 03-Jan-2011 at 9:45am

If you are looking at DevForce 2009, you can find the files at a location such as:

 C:\Program Files\IdeaBlade DevForce\Learning Resources\040_BusObjPersistence\AddingDeleting\Snippets\NumericIdGenerator

If you are looking at DevForce 2010, the files are not where you might expect them to be (i.e., in the "030_BusObjPersistence\AddingDelecting" folder).  However you can find both C# and VB versions in the "030_BusObjPersistence\_MiniDemos" folder.

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Post Options Post Options   Quote tj62 Quote  Post ReplyReply Direct Link To This Post Posted: 03-Jan-2011 at 7:55am
I have searched all over the place on my computer and it is not there the LearningResources folder does not exist. Except I find it for an old 2009 installatoin at:
    C:\Program Files\IdeaBlade DevForce\Learning Resources
But the current installatoin is at:
    C:\Program Files\DevForce 2010
where there is no Learning Resources folder at all.
 
Where in heck is it?
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pucsoftware View Drop Down
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Post Options Post Options   Quote pucsoftware Quote  Post ReplyReply Direct Link To This Post Posted: 03-Feb-2010 at 8:21am
In DevForce v5.2.4.2 on Windows 7 we found the sample class, both C# & VB versions, installed here:
 
C:\Users\Public\Documents\DevForce\Learning Resources\040_BusObjPersistence\AddingDeleting\Snippets\NumericIdGenerator
 
This may be useful if you're looking for the VB version.
puctx
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GregD View Drop Down
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Post Options Post Options   Quote GregD Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 5:18pm
/* A sample IIdGenerator implementation.
 *
 *  You can use this as-is (almost) or modify as needed.  This is provided as a sample only.
 *
 *  You may want to use an IIdGenerator to generate both temporary and real Id values for
 *  key fields of your Entities.  Note that for tables using keys based on identity or sequence/serial
 *  values the StoreGeneratedIdGenerator provided by the DevForce framework should be sufficient.
 *
 *  Possible customizations -
 *     - change the namespace
 *     - change the class name
 *     - alter IsApplicable() logic for your data source key
 *     - alter GetNextTempId() logic for custom temporary Id values
 *     - alter GetReadIdMap() logic for custom real Id allocation
 *     
 *  Place your IdGenerator class in an assembly which can be deployed on both client and server.
 *
 *  If you implement a custom IIdGenerator, place the assembly name in either the
 *  ProbeAssemblyNames for a given data source key or the ProbeAssemblyNames
 *  at the root of the IdeaBlade Configuration file.  
 *
*/
using System;
using System.Data;
using System.Runtime.Serialization;

using IdeaBlade.Ado;
using IdeaBlade.Core;
using IdeaBlade.EntityModel;

namespace IdeaBladeTest1Model {

  /// <summary>
  /// Sample IIdGenerator implementation.  The class should be marked with the Serializable
  /// or DataContract attribute if you plan to save and restore the EntityCache to/from files.
  /// </summary>
  [DataContract]
  public class NumericIdGenerator : IIdGenerator {

    /// <summary>
    /// An instance of the IIdGenerator will be instantiated by the DevForce framework
    /// on both the client and server.  A public parameterless constructor is required.
    /// </summary>
    public NumericIdGenerator() {
    }

    /// <summary>
    /// Return true if this IIdGenerator should be used with the specified key.
    /// </summary>
    /// <remarks>
    /// In this example we test the key name, but this is for illustration only.  Be sure to
    /// change this code for your implementation.  If you require an IdGenerator but DevForce
    /// can't find an "applicable" one, an exception is thrown.  Called on both client and server.
    /// </remarks>
    public bool IsApplicable(IDataSourceKey dataSourceKey) {
      return dataSourceKey.Name.StartsWith("IdeaBladeTest1");
    }

    /// <summary>
    /// Called by DevForce on the client to retrieve a temporary Id value for the specified column.
    /// </summary>
    /// <remarks>
    /// This example returns negative values starting at -1.  If you need custom temporary Ids then
    /// change this logic as necessary.
    /// Be sure to store all temporary Ids.  The framework will request them in the <see cref="TempIds"/>
    /// property.
    /// </remarks>
    public object GetNextTempId(DataEntityProperty entityColumn) {
      Object id;
      _nextBaseId++;
      long longId = (long) (-1 * _nextBaseId);
      try {
        id = Convert.ChangeType(longId, entityColumn.DataType);
      } catch {
        throw new NotSupportedException("This id generator cannot generate ids of type " + entityColumn.DataType);
      }

      _tempIds.Add(new UniqueId(entityColumn, id));
      return id;
    }  

    /// <summary>
    /// Called by DevForce on the client to retrieve a collection of the temporary Id values generated since
    /// the last <see cref="Reset"/> call.  
    /// </summary>
    /// <remarks>
    /// Be sure to maintain the collection of temporary Ids generated in <see cref="GetNextTempId"/>.
    /// </remarks>
    public UniqueIdCollection TempIds {
     get { return _tempIds; }
    }

    /// <summary>
    /// Return whether the specified Id is a temporary Id generated by this IdGenerator.
    /// </summary>
    /// <remarks>
    /// DevForce will call this on the client to test whether the specified Id is temporary and will require
    /// "fixup" as a real id.  
    /// </remarks>
    public bool IsTempId(UniqueId uniqueId) {
      if (_tempIds == null) {
        return false;
      }
      return _tempIds.Contains(uniqueId);
    }

    /// <summary>
    /// Called by DevForce after an EntityManager.SaveChanges call is performed and all temporary Id values
    /// have been "fixed up" as real Ids.  Use this to clear your temporary Id collection and reset counters.
    /// </summary>
    public void Reset() {
      _tempIds.Clear();
      _nextBaseId = 0;
    }

    /// <summary>
    /// Called by DevForce from the BOS to retrieve "real" Id values for the temporary Ids passed.
    /// </summary>
    /// <remarks>
    /// You can retrieve "real" Ids in any manner you like - this sample shows allocation
    /// of Ids from a single table holding a global sequence value.
    /// You must return a UniqueIdMap from this method containing a real Id value for each
    /// temporary Id.  Note that the UniqueId objects passed in contain information on the
    /// EntityColumn used.  You can use this information to perform more complex Id allocation
    /// if needed.
    /// Because this method is called from the server, and the server is multi-threaded,
    /// you must provide synchronization logic to handle concurrent requests.  In this
    /// sample, a lock is used within the GetNextId logic.
    /// </remarks>
    public UniqueIdMap GetRealIdMap(UniqueIdCollection tempIds, IDataSourceKey dataSourceKey ) {

      UniqueIdMap idMap = new UniqueIdMap();

      long nextLongId = GetNextId(tempIds.Count, dataSourceKey);
      object nextId;

      // Build a UniqueIdMap containing the mapping of temporary to real Id values.
      foreach (UniqueId aUniqueId in tempIds) {
        try {
          nextId = Convert.ChangeType(nextLongId, aUniqueId.Property.DataType);
        } catch {
          throw new NotSupportedException("This id generator cannot generate ids of type " + aUniqueId.Property.DataType);
        }

        idMap.Add(aUniqueId, nextId);
        nextLongId++;
      }

      return idMap;
    }

    #region Server-side custom Id allocation

    /// <summary>
    /// Perform allocation and return the starting next Id value.
    /// This sample disallows Id allocation for more than MaxGroupSize (1000) values
    /// at a time.  It also always allocates 100 new values at a time.
    /// These numbers are arbitrary, and for illustration only.  
    /// </summary>
    private long GetNextId(int count, IDataSourceKey dataSourceKey) {

      // Serialize access to GetNextId - the BOS is multi-threaded and concurrent saves can be in progress.
      lock (__syncLock) {

        // Do some validation before proceeding.
        TraceFns.Assert(count > 0, "GetNextId requires a positive integer as its arg.");

        TraceFns.Assert(count <=  MaxGroupSize,"Cannot allocate more than "
          + MaxGroupSize + " in any one call to GetNextId");

        // Allocate more Ids only if necessary.  This allocates 100 at a time.
        if (__nextId + count > __maxNextId) {
          AllocateMoreIds(count, dataSourceKey);
        }

        long result = __nextId;
        __nextId += count;        // Next time we'll start here.
        return result;
      }
    }

    /// <summary>
    /// Allocate more "real" Id values.  This sample uses a table called NextId with
    /// "Name" and "NextId" columns.  It uses a "global" allocation strategy - that is,
    ///  Id values are not assigned on a table-specific basis, but globally within the application.
    /// </summary>
    private void AllocateMoreIds(int count, IDataSourceKey dataSourceKey) {
      const String sqlSelect = "select NextId from NextId where Name = 'GLOBAL'";
      const String sqlUpdate = "update NextId set NextId={0} where Name = 'GLOBAL' and NextId={1}";

      // Allocate the larger of the two:  amount requested or the default alloc group size.
      count = Math.Max(count, DefaultGroupSize);

      AdoHelper adoHelper = GetAdoHelper(dataSourceKey);
      IDbConnection aConnection = adoHelper.CreateDbConnection(true);
      aConnection.Open();

      using (aConnection) {
        IDbCommand selectCommand =  adoHelper.CreateDbCommand(aConnection);
        IDbCommand updateCommand = adoHelper.CreateDbCommand(aConnection);

        for (int trys = 0 ; trys <= MaxTrys ; trys++) {
          
          selectCommand.CommandText = sqlSelect;    
          IDataReader aDataReader = selectCommand.ExecuteReader();
          if (!aDataReader.Read()){
            throw new ApplicationException("Unable to locate 'NextId' record");
          }

          Object tmp = aDataReader.GetValue(0);
          long nextId = (long) Convert.ChangeType(tmp, typeof(Int64));
          long newNextId = nextId + count;
          aDataReader.Close();

          // Update the table to reflect the new NextId value to be assigned next time.
          updateCommand.CommandText = String.Format(sqlUpdate, newNextId, nextId);
         
          // If only one record was affected - we're ok; otherwise try again.
          if (updateCommand.ExecuteNonQuery() == 1) {
            __nextId = nextId;
            __maxNextId = newNextId;
            return;
          }
        }
      }
      throw new ApplicationException("Unable to generate a new id");
    }

    /// <summary>
    /// Retrieve an AdoHelper to use in data access.  This sample issues
    /// select and update commands to the database, using the AdoHelper.
    /// </summary>
    private AdoHelper GetAdoHelper(IDataSourceKey dataSourceKey) {

      // Option 1 - if you want to reference both IdeaBlade.EntityModel.Edm.v4
      //  and IdeaBlade.Rdb.v4 assemblies.
      IdeaBlade.EntityModel.Edm.EdmKey edmKey =
        dataSourceKey as IdeaBlade.EntityModel.Edm.EdmKey;
      RdbKey rdbKey = edmKey.RdbKey as RdbKey;
      return rdbKey.AdoHelper;


      // Option 2 - you might not want to reference the IdeaBlade.EntityModel.Edm.v4 assembly on your
      //  client (since it in turn references Entity Framework assemblies).  You could instead use
      //  a little reflection.
      //      Type t = InternalFns.GetIdeaBladeType("IdeaBlade.EntityModel.Edm.v4.EdmKey", true);
      //      RdbKey rdbkey = t.GetProperty("RdbKey").GetValue(dataSourceKey, null) as RdbKey;
      //      return rdbkey.AdoHelper;


      // Option 3 - You can create separate client-side vs. server-side IdGenerator implementations.
      //  Contact IdeaBlade for more information.

    }
    #endregion

    // Client-side variables.
    [DataMember]
    private UniqueIdCollection _tempIds = new UniqueIdCollection();
    [DataMember]
    private int _nextBaseId;

    private const int  MaxTrys           = 3;       // Fail after 3 unsuccessful allocation attempts.
    private const int  DefaultGroupSize  = 100;     // Allocate 100 new Ids at a time.
    private const int  MaxGroupSize      = 1000;    // Only allow 1000 Ids max in a call.

    // Server-side variables.
    private static object __syncLock = new object();
    private static long __nextId       = 0;
    private static long __maxNextId    = 0;
   
  }
}
 
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davidklitzke View Drop Down
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Post Options Post Options   Quote davidklitzke Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 2:26pm

I have seen some rare cases where the Learning Resources get installed to C:\MyTutorials or D:\MyTutorials (or some other drive:\MyTutorials).  I think if you look hard enough, you can find the Learning Resources.  It is extremely rare for the Learning Resources not to get installed somewhere on your hard drive.

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Post Options Post Options   Quote dpollot44 Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 1:00pm
...And I spoke too soon.  I've reinstalled a couple of times and the learning folder is empty each time.  Can someone just post the sample code (specifically looking for NumericIdGenerator).

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Post Options Post Options   Quote dpollot44 Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 12:35pm
I reinstalled.  The full/vs. custom install didn't include the learning units.
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Post Options Post Options   Quote dpollot44 Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 12:14pm
I forgot to mention that the "LearningResources" folder is empty for me (I had tried to do a quick search for the .cs file and it would have found it there otherwise).  Do I just need to re-download and extract?  Perhaps a different version?
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Post Options Post Options   Quote GregD Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 11:19am
Between August and now, the Learning Resources were reorganized and the sample implementation of IidGenerator was moved to the following location:

     LearningResources\040_BusObjPersistence\AddingDeleting\Snippets\NumericIdGenerator


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Post Options Post Options   Quote dpollot44 Quote  Post ReplyReply Direct Link To This Post Posted: 13-Jan-2010 at 8:52am
I'm evaluating the software (universal) and that directory does not exist for me.  There are three sub-folders; Documentation, Learning Resources, and SilverLight Assemblies... I would have thought perhaps either of the first two might contain the sample implementations but nope.

Is the code posted somewhere (saving me the time of re-downloading/registering)
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Post Options Post Options   Quote GregD Quote  Post ReplyReply Direct Link To This Post Posted: 24-Aug-2009 at 4:13pm
There are a couple of mentions of IIDGenerator in the Developer Guide, which describe at a high level what it does. Other than that, there is a sample implementation (NumericIDGenerator) included in the C:\Program Files\IdeaBlade DevForce\Samples.
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Post Options Post Options   Quote Suah Quote  Post ReplyReply Direct Link To This Post Posted: 20-Aug-2009 at 9:52pm
Where can I find document for how to implement the GenerateID() interface?
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