CentRepExample: -Using Central Repository for Persistent Storage

Description

Several -Symbian platform components have state and settings information that need -to be persistent. There is also a global state that needs to persist, for -example, default filenames, locale settings, user preferences.

The -CentRep example application first registers a group of settings with the central -repository server. It uses E80000AD.txt, a UTF-16 format -text file to initialise the repository. This text file contains access control -structure and the initial content of the repository. It is recommended to -convert the initialisation text file into a binary file using the central -repository converter tool to speed up the execution.

The application -creates a CRepository object using the CRepository::NewLC() method -to access a repository using its UID. It resets the whole repository using CRepository::Reset() method -with the contents in the initialisation file.

Each setting stored -in the repository will have a unique key to identify the setting. This unique -key is used to read and change the setting by calling the CRepository::Get() and CRepository::Set() methods -respectively. The application moves these keys to a different location using CRepository::Move() method -and deletes them from their original location.

The application also -creates another CRepository object to demonstrate that, at -any given point a repository cannot be opened with READ/WRITE access -by more than one client. In such situations, it is recommended to start a -transaction before a write operation using CRepository::StartTransaction() method. -A transaction guarantees the consistency and persistence of all values read -and written during the transaction.

Finally, the application requests -the central repository server to notify any changes to the original settings.

Related -APIs

CRepository - Provides access to a repository.
CRepository::Get()
CRepository::Move()
CRepository::NewLC()
CRepository::Reset()
CRepository::Set()
CRepository::StartTransaction()

Download

Click -on the following link to download the example: CentRepExample.zip

Click: browse to view the example code.

Build

The Symbian build process describes -how to build an application.

The CentRepExample builds -an executable called CentRepExample.exe in the standard -location (\epoc32\release\winscw\<build_variant > for CodeWarrior). -After launching the executable, depending on the emulator you are using, you -may need to task away from the app launcher/shell screen to view the console.

+ + + + + +CentRepExample: Using Central Repository for Persistent StorageThis example application demonstrates the usage of Central +Repository API for persistent storage. +

Description

Several Symbian platform components have state and settings information +that need to be persistent. There is also a global state that needs +to persist, for example, default filenames, locale settings, user +preferences.

The CentRep example application first registers +a group of settings with the central repository server. It uses E80000AD.txt, a UTF-16 format text file to initialise +the repository. This text file contains access control structure and +the initial content of the repository. It is recommended to convert +the initialisation text file into a binary file using the central +repository converter tool to speed up the execution.

The application +creates a CRepository object using the CRepository::NewLC() method to access a repository using +its UID. It resets the whole repository using CRepository::Reset() method with the contents in the initialisation file.

Each +setting stored in the repository will have a unique key to identify +the setting. This unique key is used to read and change the setting +by calling the CRepository::Get() and CRepository::Set() methods respectively. The application +moves these keys to a different location using CRepository::Move() method and deletes them from their original location.

The +application also creates another CRepository object +to demonstrate that, at any given point a repository cannot be opened +with READ/WRITE access by more than one client. In such situations, +it is recommended to start a transaction before a write operation +using CRepository::StartTransaction() method. A +transaction guarantees the consistency and persistence of all values +read and written during the transaction.

Finally, the application +requests the central repository server to notify any changes to the +original settings.

Related APIs

CRepository - Provides access to a repository.
CRepository::Get()
CRepository::Move()
CRepository::NewLC()
CRepository::Reset()
CRepository::Set()
CRepository::StartTransaction()

Download

Click on the following link to download the example: CentRepExample.zip

Click: browse to view the example code.

Build

The Symbian build process describes how to build an application.

The CentRepExample builds an +executable called CentRepExample.exe in the standard +location (\epoc32\release\winscw\<build_variant > for CodeWarrior). +After launching the executable, depending on the emulator you are +using, you may need to task away from the app launcher/shell screen +to view the console.

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