Central Repository Data Access Tutorial

This tutorial describes how to access and modify the data in Central Repository at run time on the Symbian platform.

Steps

1. Open a repository

   The repositories are identified by a UID. To access the data in the Central Repository create a new [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]CRepository object with the UID of the repository.

   Example:

   CRepository* repository = CRepository::NewL(KMyRepositoryUid);

   One [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]CRepository object must be created for each repository.

2. Retrieve data from the repository

   The data can be retrieved by using [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Get() or [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Find() functions of the [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]CRepository class.

   1. Use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Get() to retrieve an individual value

      Example:

      TInt Get(TUint32 aKey, TInt& aVal);    

   2. Use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Find() function to retrieve the values by passing a range of keys The input parameters are a partial key and a key mask and the function returns all the settings that match the input range.

      Example:

      TInt FindL(TUint32 aPartialKey, TUint32 aKeyMask, RArray<TUint32>& aFoundKeys);

      aKey parameter represents a setting in a 32 bit unsigned integer and aVal represents the corresponding value of the setting.

3. Modify the data of the repository opened

   The [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Set() functions of the [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]CRepository class allows the applications to modify the data in the Central Repository.

   Set new values using [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Set()

   Example:

   TInt Set(TUint32 aKey, TInt aVal);
   

4. Read the metadata of the repository

   1. Use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]GetMeta() to get the metadata of the repository. The eight most significant bits are reserved for internal purpose and clients must not use these values. The value of the reserved bits may change for each [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]GetMeta() call.

   2. Applications must use logical AND function with the return value of [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]GetMeta() and the constant [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]KMetaUnreserved to retrieve the user bits of the metadata. The constant KMetaUnreserved is defined in centralrepository.h.

   Example:

   TInt GetMeta(TUint32 aKey, TUint32& aMeta);

5. Add a new setting

   To add a new setting in the repository use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Create().

   Example:

   TInt Create(TUint32 aKey, TInt aVal);

   To delete an existing setting use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Delete()

   Example:

   TInt Delete(TUint32 aKey);

6. Move settings

   To move one or more settings from one key to another key use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Move()

   Example:

   TInt Move (TUint32 aSourcePartialKey, TUint32 aTargetPartialKey, TUint32 aMask, TUint32 &aErrorKey) ;

   The source key, target key and the partial mask must be provided by the clients.

7. Reset the settings

   1. To reset the settings of a repository to the default values use [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Reset()

      Example:

      TInt Reset();

   2. To reset a particular setting, pass the key of the setting as a parameter to the [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]Reset() function.

      Example:

      TInt Reset(TUint32 aKey);

      Go back to step 2 if you want to modify the settings after a reset or continue to step 8

8. Close the repository

   To close repository, use delete.

   Example:

   delete repository;
   

   Each instance of the [[[ERROR: [NOKX000E] Unable to find definition for key reference 'CRepository']]]CRepository object must be deleted to clean up the resources.