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Contents 1 Introduction 2 Settings.h 3 Settings.cpp 4 YourApp.cpp 5 Your Document.cpp 6 Other Related Topics

Introduction

Most applications need some way to store persistent data. In most cases, the use of ini files is the easiest way to achieve this. Here's a simple setting class providing both loading and storing methods.

Settings.h

#ifndef SETTINGS_H
#define SETTINGS_H
 
#include <e32base.h> // CBase
#include <e32def.h> // TBool
 
class CApaApplication;
 
class CSettings : public CBase
{
public:
    CSettings(CApaApplication& aApp);
    void ConstructL();
 
    void LoadL();
    void StoreL();
 
public:
    TBool iStartOnBackground;
    // Other settings...
 
private:
    CApaApplication& iApp;
};
 
#endif

Settings.cpp

And the class implementation could be something like this:

#include "Settings.h"
#include "YourApp.h"
 
#include <coemain.h> // CCoeEnv
#include <s32stor.h> // CDictionaryStore
 
CSettings::CSettings(CApaApplication& aApp) : iApp(aApp)
{}
 
void CSettings::ConstructL()
{
    LoadL();
}
 
void CSettings::LoadL()
{
    CDictionaryStore* iniFile = iApp.OpenIniFileLC(CCoeEnv::Static()->FsSession());
 
    if (iniFile->IsPresentL(KYourAppUid))
    {
        RDictionaryReadStream readStream;
        readStream.OpenLC(*iniFile, KYourAppUid);
 
        TUint16 version = static_cast<TUint16> (readStream.ReadUint16L());
 
        iStartOnBackground = static_cast<TBool> (readStream.ReadInt8L());
        // Initialize other settings
 
        CleanupStack::PopAndDestroy(&readStream);
    }
    else
    {
        // ini doesn't exist, so use default values
        iStartOnBackground = EFalse;
    }
 
    CleanupStack::PopAndDestroy(iniFile);
}
 
void CSettings::StoreL()
{
    CDictionaryStore* iniFile = iApp.OpenIniFileLC(CCoeEnv::Static()->FsSession());
    RDictionaryWriteStream writeStream;
    writeStream.AssignLC(*iniFile, KYourAppUid);
 
    // You may support some simple versioning if you wish
    writeStream.WriteInt16L(KYourAppVersion);
 
    writeStream.WriteInt8L(iStartOnBackground);
 
    writeStream.CommitL();
    iniFile->CommitL();
    CleanupStack::PopAndDestroy(2, iniFile);
}

YourApp.cpp

You should keep in mind to override your Application's OpenIniFileLC(), as some frameworks (Avkon for instance) disable ini file creation by default.

CDictionaryStore* CYourApp::OpenIniFileLC(RFs& aFs) const
{
    return CEikApplication::OpenIniFileLC(aFs);
}

Your Document.cpp

A good place to instantiate your setting class could be in your Document or AppUi classes:

void CYourAppDocument::ConstructL()
{
    // Load settings from ini file
    iSettings = new(ELeave) CSettings(*Application());
    iSettings->ConstructL();
}
 
CYourAppDocument::~CYourAppDocument()
{
    delete iSettings;
}

Other Related Topics

Using .ini Files

RDictionaryReadStream

RDictionaryWriteStream