path: root/development/pim/pim_howto/pim_howto.lyx

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% /Title   ClearSim-RealtTime und Andere
%  /Creator (Tex)
%  /Author  (Stefan Eilers)
%  /Subject ()
%  /Keywords (Simulation,Real-Time,ClearSim,prototype,efsm)
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\layout Title

How to use the Opie-Pim API without getting tired!
\newline 
(Aka: Hitchhikers Guide Through the Opie-Pim API)
\newline 
(Pre V 0.1)
\layout Author


\family sans 
Stefan Eilers
\layout Section*


\family sans 
Abstract
\layout Standard

The Opie-Pim API provides a powerfull access interface to the PIM (Personal
 Information Management) data which contains your contact information, the
 dates in your calendar tool (in this paper called datebook events) and
 your todo events.
 Beside providing full featured access to this information, it covers the
 real management of this informantion - the access of the databases - from
 the user.
 
\layout Standard

While starting to read the automatically generated API-documentation, the
 user may be confused by a lot of unnecessary classes and details which
 makes the quick start not as easy as possible.
 Due to the fact that a user will not need most of the details, this paper
 should help to start to become confortable with those details he need to
 solve his problems.
\layout Standard


\begin_inset LatexCommand \tableofcontents{}

\end_inset 


\layout Chapter

Introduction
\layout Standard

Before starting to jump into the work, we should introduce some specialties
 of the PIM API, first.
 To know these facts should help to avoid possible irritations and misunderstand
ings:
\layout Enumerate

The PIM-API heavily uses C++ templates (as known as generic classes), but
 you don't have to understand very deeple what templates are doing and how
 they work! Most of the API works without even seeing the templates.
 In some cases we have to use them (for instance to use the factory classes),
 but this guide will provide examples which should help to find the path
 through.
 But it is a good idea to read some short introduction of templates to avoid
 unnecessary mistakes.
\layout Enumerate

The PIM-API is split into two parts: The 
\emph on 
frontend
\emph default 
 and the 
\emph on 
backend.

\emph default 
 While the frontend provides the API for the user, the backend implements
 how to access the databases and what to do with the data.
 As we just want to access data, this paper just focuses the frontend.
 Thus, you should ignore all classes which contains something like 
\begin_inset Quotes gld
\end_inset 

backend
\begin_inset Quotes grd
\end_inset 

 in its name! Backends are just interesting for people who want to extend
 or implement new possibilities about how to access databases, which will
 be discussed at the end of this paper.
 Currently, you just have to understand that there do exist several backends
 for every type of PIM data (Contact, Todo, Datebook) which controls whether
 you want to access an XML, SQL (SQLite) or VCard style database.
 If you just want to use the default database, you even don't have to think
 about this!
\layout Standard

In the next chapter, we will show how to access the default database as
 easy as possible.
 This will be the solution for most of the problems you may face while accessing
 the PIM data.
\layout Chapter

Quick Guide to access the Database
\layout Standard

In this chapter we will introduce very quickly how to get access to the
 database and how to access data.
 It should help to find the right directions.
 If it is too short for you, you should read the next chapter afterwards
 to find a more complete and detailed view into the system.
\layout Section

Instantiate the access-object
\begin_inset LatexCommand \label{sec:Instantiate-the-Access}

\end_inset 


\layout Standard

To gain access to the database you need something we will call
\emph on 
 access-object
\emph default 
 (an instance of the access-class for the database) which handles the database
 access.
 Requesting such an object is very easy by using the operation 
\emph on 
defaultAccess()
\emph default 
 of the factory class 
\series bold 
OPimAccessFactory
\series default 
 (see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimAccessFactory.html}

\end_inset 

).
 This operation is defined like this:
\layout LyX-Code

T* defaultAccess (typename OPimGlobal::PimType type, const QString &appName)
\layout Standard

You just have to add the following lines to your source code to use it (this
 example is for accessing the contact database):
\layout LyX-Code

#include <opie2/opimaccessfactory.h>
\layout LyX-Code

use namespace Opie;
\layout Standard

[...]
\layout LyX-Code

OPimContactAccess* sourceDB = OPimAccessFactory<OPimContactAccess>::defaultAcces
s( OPimGlobal::CONTACTLIST, "my-app" );
\layout Standard

If everything works as expected, you will receive a pointer to the contact
 access-class which has to be used for accessing the database.
 Accessing the datebook database works equally
\begin_inset Foot
collapsed false

\layout Standard

The API will be changed in the future: ODateBookAccess will be renamed to
 OPimEventAccess.
\end_inset 

:
\layout LyX-Code

ODateBookAccess* sourceDB = OPimAccessFactory<ODatebookAccess>::defaultAccess(
 OPimGlobal::DATEBOOK, "my-app" );
\layout Standard

And the same for todo:
\layout LyX-Code

OPimTodoAccess* sourceDB = OPimAccessFactory<OPimTodoAccess>::defaultAccess(
 OPimGlobal::TODOLIST, "my-app" );
\layout Standard

Using 
\emph on 

\begin_inset Quotes gld
\end_inset 

defaultAccess()
\begin_inset Quotes grd
\end_inset 


\emph default 
, the default database is accessed automatically
\begin_inset Foot
collapsed false

\layout Standard

The configuration file 
\begin_inset Quotes gld
\end_inset 

pimaccess.conf
\begin_inset Quotes grd
\end_inset 

 defines which backend is selected as default!
\end_inset 

.
 If you want to use anything else, you have to read the next chapter to
 get the information how to do this.
 
\layout Standard

The last parameter 
\begin_inset Quotes gld
\end_inset 

my-app
\begin_inset Quotes grd
\end_inset 

 is very importand and should be equal for every instance of an application.
 Some database backends (like the XML backend) uses this string as an unique
 filename to create a journal file.
 If your application should run in several instances independently you will
 need multiple journal files and therefore several name strings!
\layout Standard

If the database access-object is is not needed anymore, you have to remove
 it by calling 
\emph on 
delete
\emph default 
:
\layout LyX-Code

delete sourceDB;
\layout Section

Accessing the Access-Object
\begin_inset LatexCommand \label{sec:Accessing-the-access-object}

\end_inset 


\layout Standard

After receiving the access-object, we just have to use its API which is
 mainly defined by the common base class 
\series bold 
OPimAccessTemplate
\series default 
 (see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimAccessTemplate.html}

\end_inset 

).
 This API is inherited by all access-classes and therefore common to all
 access-objects.
 We will show the most important operations of it first (please replace
 
\begin_inset Quotes gld
\end_inset 

T
\begin_inset Quotes grd
\end_inset 

 below with the corresponding 
\emph on 
data-class
\emph default 
 for the selected access-class: OPimContact
\begin_inset Foot
collapsed false

\layout Standard

see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimContact.html}

\end_inset 


\end_inset 

 for OPimContactAccess, OPimEvent
\begin_inset Foot
collapsed false

\layout Standard

see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimEvent.html}

\end_inset 


\end_inset 

 for ODateBookAccess and OPimTodo
\begin_inset Foot
collapsed false

\layout Standard

see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimTodo.html}

\end_inset 


\end_inset 

 for OPimTodoAccess):
\layout LyX-Code

bool load ();
\layout LyX-Code

bool reload ();
\layout LyX-Code

bool save ();
\layout LyX-Code

\layout LyX-Code

bool add (const T& t);
\layout LyX-Code

bool remove (const T& t);
\layout LyX-Code

bool replace (const T& t);
\layout Standard

After receiving an access-object, we have to load the existing dataset into
 the backend, which is done by the 
\begin_inset Quotes gld
\end_inset 

load()
\begin_inset Quotes grd
\end_inset 

 operation.
 The 
\begin_inset Quotes gld
\end_inset 

save()
\begin_inset Quotes grd
\end_inset 

 operation is important to write back (or 
\emph on 
commit
\emph default 
) local changes into the global database.
 After doing this, the changes are globally accessable! The 
\begin_inset Quotes gld
\end_inset 

reload()
\begin_inset Quotes grd
\end_inset 

 operation loads changes of the global database into the local set 
\series bold 
without
\series default 
 removing any local changes
\begin_inset Foot
collapsed false

\layout Standard

We should check whether all databases behave like this! (se)
\end_inset 

.
 This may be done after receiving information about any change by an other
 application which is not in scope of this chapter.
 The other operations are self explaining and should work as expected.
\layout Standard

If you want to work with the existing dataset, you need to get a list of
 all available information.
 This list is returned by the call 
\begin_inset Quotes gld
\end_inset 

allRecords()
\begin_inset Quotes grd
\end_inset 

 which returns a list of all available records as an 
\series bold 
OPimRecordList
\series default 
 (see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimRecordList.html}

\end_inset 

).
 
\layout LyX-Code

List allRecords();
\layout Standard

In fact, this 
\emph on 
List
\emph default 
 just contains a list of uid's to take care of memory space.
 As every record is identified by an unique identification number which
 is called UID (Unique Identification), these numbers just exists once in
 the database which is currently on access! To receive the real record,
 you have to use the operation 
\begin_inset Quotes gld
\end_inset 

find()
\begin_inset Quotes grd
\end_inset 

 with a valid UID as parameter:
\layout LyX-Code

T find (UID uid);
\layout Standard

This is all you need to realize a basic access to the PIM-Databases! The
 next chapter will guide you into more details of the PIM-API.
\layout Chapter

How to Access PIM-Data: Detailed View
\layout Standard

As shown in the previous chapter, all we need to access the PIM-Database
 is to request an access-object from the OPimAccessFactory and to use it.
 We will now introduce some special features of this factory (see section
 
\begin_inset LatexCommand \ref{sec:Advanced-Factory-Features}

\end_inset 

), followed by some very important features like searching and sorting in
 section 
\begin_inset LatexCommand \ref{sec:Special-Features:-Searching}

\end_inset 

.
 If you are interested in accessing data without take care about their types,
 section 
\begin_inset LatexCommand \ref{sec:Generic-Access:-OPimBase}

\end_inset 

 will show how to do this, followed by a short introduction about delayed
 loading in section 
\begin_inset LatexCommand \ref{sec:Internal-Signal-Handling:}

\end_inset 

.
\layout Standard

But first we will start with introducing some features of the 
\series bold 
OPimAccessFactory
\series default 
.
\layout Section

Advanced Factory Features
\begin_inset LatexCommand \label{sec:Advanced-Factory-Features}

\end_inset 


\layout Standard

In the previous chapter we used the operation 
\begin_inset Quotes gld
\end_inset 

defaultAccess()
\begin_inset Quotes grd
\end_inset 

 to request an access-object to the default backend.
 Whether this default backend will access the XML, VCard or SQLite database
 type, is defined by the configuration file 
\begin_inset Quotes gld
\end_inset 

pimaccess.conf
\begin_inset Quotes grd
\end_inset 

 which is stored in the directory 
\begin_inset Quotes gld
\end_inset 

Settings
\begin_inset Quotes grd
\end_inset 

, stored in the user home directory.
 Changing this setting will take effect to all applications using 
\begin_inset Quotes gld
\end_inset 

defaultAccess()
\begin_inset Quotes grd
\end_inset 

.
 Therefore it is not a good idea to modify a global setting, if an application
 should access a special database type, for instance to move data from one
 database to an other.
 
\layout Standard

If the developer wants to select a special database type for sure without
 unnecessary side effects, he has to use the operation 
\emph on 
create()
\emph default 
 which has the following parameters:
\layout LyX-Code

T* create (OPimGlobal::PimType type, OPimGlobal::DatabaseStyle dbStyle,
 const QString &appName, const QString &fileName=QString::null)
\layout Standard

Some parameters are already known, like type and appName (see section 
\begin_inset LatexCommand \ref{sec:Instantiate-the-Access}

\end_inset 

).
 The new parameter 
\begin_inset Quotes gld
\end_inset 

dbStyle
\begin_inset Quotes grd
\end_inset 

 defines which database type should be selected.
 Possible values could be found in the enumeration 
\emph on 
DataBaseStyle
\emph default 
 in the class 
\series bold 
OPimGlobal
\series default 
 (see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1Pim_1_1OPimGlobal.html}

\end_inset 

).
 
\begin_inset Quotes gld
\end_inset 

DEFAULT
\begin_inset Quotes grd
\end_inset 

 selects the default database and therefore behaves exactly as the operation
 
\begin_inset Quotes gld
\end_inset 

defaultAccess()
\begin_inset Quotes grd
\end_inset 

 above.
 
\begin_inset Quotes gld
\end_inset 

UNKOWN
\begin_inset Quotes grd
\end_inset 

 is just defined for internal reasons and should not be used be the developer.
 The remaining values (
\begin_inset Quotes gld
\end_inset 

XML
\begin_inset Quotes grd
\end_inset 

, 
\begin_inset Quotes gld
\end_inset 

SQL
\begin_inset Quotes grd
\end_inset 

, 
\begin_inset Quotes gld
\end_inset 

VCARD
\begin_inset Quotes grd
\end_inset 

) should be used to select the desired database backend.
 The last parameter 
\begin_inset Quotes gld
\end_inset 

fileName
\begin_inset Quotes grd
\end_inset 

 is used to select a special file name and path to the database file.
 Thus, you can use it to access database files which don't reside on the
 default path or have other filenames as it is defined by the platform as
 default (in normal cases 
\begin_inset Quotes gld
\end_inset 

~/Applications/<name of application>/
\begin_inset Quotes grd
\end_inset 

).
\layout Standard

In the next section we will discuss how searching and sorting take place
 with this API.
\layout Section

Special Features: Searching and Sorting
\begin_inset LatexCommand \label{sec:Special-Features:-Searching}

\end_inset 


\layout Standard

In most cases it is not sufficient to receive just a list of all information
 in a database.
 It is essential to get a subset of the information available and to be
 able to sort it.
 For this kind of exercise we provide some special operations which provide
 searching and sorting in an incremental manner
\begin_inset Foot
collapsed false

\layout Standard

FIXME: matchRegexp() does take a list of uid's.
 Therefore it is currently not possible to use it in an incremental manner!
 (se)
\end_inset 

.
 Therefore it is possible to research a 
\begin_inset Quotes gld
\end_inset 

List
\begin_inset Quotes grd
\end_inset 

 which was returned by a previous search query and to sort it afterwards.
 Before we will take a close look into sorting, we will start with searching.
 There exist two different ways of searching:
\layout Enumerate

Search a complete database for a special regular expression, using 
\begin_inset Quotes gld
\end_inset 

matchRegexp ()
\begin_inset Quotes grd
\end_inset 

.
 This search type returns all records which contains the given regular expressio
n 
\emph on 
anywhere
\emph default 
 in the dataset.
 This search type is used for example by the opie search tool (OSearch)
 (see 
\begin_inset LatexCommand \url{http://handhelds.org/cgi-bin/cvsweb.cgi/opie/core/pim/osearch/}

\end_inset 

 and 
\begin_inset LatexCommand \url{http://handhelds.org/cgi-bin/cvsweb.cgi/opie/core/pim/osearch/adresssearch.cpp?rev=1.12&content-type=text/x-cvsweb-markup}

\end_inset 

).
\layout Enumerate

Define a so called 
\begin_inset Quotes gld
\end_inset 

Query By Example
\begin_inset Quotes grd
\end_inset 

 search query which allows to define what should be searched and which internal
 data fields should be taken into account.
 This is a very advanced search function which allows to search in a very
 fine granular manner.
\layout Standard

We will start with the first and very simple 
\begin_inset Quotes grd
\end_inset 

matchRegexp()
\begin_inset Quotes grd
\end_inset 

, followed by the query by example search query.
\layout Subsection

Searching with 
\begin_inset Quotes gld
\end_inset 

matchRegexp()
\begin_inset Quotes grd
\end_inset 


\layout Standard

The function is defined like this:
\layout LyX-Code

List matchRegexp (const QRegExp& r);
\layout Standard

The 
\begin_inset Quotes gld
\end_inset 

List
\begin_inset Quotes grd
\end_inset 

 is still a OPimRecordList which contains 0 or more uid's of matching records.
 As already discussed in section 
\begin_inset LatexCommand \ref{sec:Accessing-the-access-object}

\end_inset 

 you have to use the 
\begin_inset Quotes gld
\end_inset 

find()
\begin_inset Quotes grd
\end_inset 

 operation to request the real records.
\layout Subsection

Searching with Query By Example
\layout Standard

The query by example search style is working is using a data object (for
 instance an OPimContact) to store the search query.
 For instance, if you want to request all entries which contains the last
 name 
\begin_inset Quotes gld
\end_inset 

Eilers
\begin_inset Quotes grd
\end_inset 

 and the home zip number should start with 
\begin_inset Quotes gld
\end_inset 

3
\begin_inset Quotes grd
\end_inset 

 you have to do the following:
\layout LyX-Code

OPimContact searchQuery;
\layout LyX-Code

searchQuery.setLastName( 
\begin_inset Quotes eld
\end_inset 

Eilers
\begin_inset Quotes erd
\end_inset 

 );
\layout LyX-Code

searchQuery.setHomeZip( 
\begin_inset Quotes eld
\end_inset 

3*
\begin_inset Quotes srd
\end_inset 

 );
\layout Standard

We use an usual 
\begin_inset Quotes gld
\end_inset 

OPimContact
\begin_inset Quotes grd
\end_inset 

 and fill into two fields the query information.
 All filled fields are taken for the search operation (using an 
\begin_inset Quotes gld
\end_inset 

AND
\begin_inset Quotes grd
\end_inset 

 operation), the unused ones are simply ignored.
 As we just want to search for entries which zip number starts with a 
\begin_inset Quotes gld
\end_inset 

3
\begin_inset Quotes grd
\end_inset 

 we use the Wildcard 
\begin_inset Quotes gld
\end_inset 

*
\begin_inset Quotes grd
\end_inset 

 as we would do to find files in a filesystem.
\layout Standard

The next step is to put this query into the operation which is defined like
 this:
\layout LyX-Code

List queryByExample (const T& query, int querySettings, const QDateTime&
 startperiod=QDateTime())
\layout Standard

The first parameter 
\begin_inset Quotes gld
\end_inset 

query
\begin_inset Quotes grd
\end_inset 

 should used to set our query, but we have to set the parameter 
\begin_inset Quotes gld
\end_inset 

querySettings
\begin_inset Quotes grd
\end_inset 

 to configure the search properly.
 This settings are defined by the enumeration 
\begin_inset Quotes gld
\end_inset 

QuerySettings
\begin_inset Quotes grd
\end_inset 

 in the class 
\series bold 
OPimBase
\series default 
 (see 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/structOpie_1_1OPimBase.html#w19}

\end_inset 

).
 The meaning of all settings will be discussed later.
 For the first turn we will just concentrate on the things we need in this
 case.
 As we use Wildcards in 
\begin_inset Quotes gld
\end_inset 

setHomeZip
\begin_inset Quotes grd
\end_inset 

 we have to use 
\begin_inset Quotes gld
\end_inset 

WildCards
\begin_inset Quotes grd
\end_inset 

.
 And we want to be sure to find lower case names, too, which may be mistyped
 (like 
\begin_inset Quotes gld
\end_inset 

eilers
\begin_inset Quotes grd
\end_inset 

, 
\begin_inset Quotes gld
\end_inset 

eIlers
\begin_inset Quotes grd
\end_inset 

, ...).
 Thus, we have to use the 
\begin_inset Quotes gld
\end_inset 

IgnoreCase
\begin_inset Quotes grd
\end_inset 

 setting which is to combine with the other using an 
\begin_inset Quotes gld
\end_inset 

or
\begin_inset Quotes grd
\end_inset 

 operator.
 The last parameter 
\begin_inset Quotes gld
\end_inset 

endperiod
\begin_inset Quotes grd
\end_inset 

 will be ignored for this case which will look like this:
\layout LyX-Code

use namespace Opie;
\layout LyX-Code

[...]
\layout LyX-Code

List found_items = queryByExample( searchQuery, OPimBase::WildCards | OpimBase::
IgnoreCase );
\layout Standard

This operation may return a list of entries which can be accessed as above,
 using the 
\begin_inset Quotes gld
\end_inset 

find()
\begin_inset Quotes grd
\end_inset 

 operation.
\layout Standard

It should be clear at this stage, that this query is very powerful and -
 depending to the querySettings - could be very complicated to implement.
 Thus, not all backends do support all features defined by querySettings
\begin_inset Foot
collapsed false

\layout Standard

At this time, just the contact database for XML and VCard is supporting
 all queries and combination of them.
 All others just support subsets.
\end_inset 

.
 To check which settings are supported and to be able to react dynamically
 on missing features (for instance to disable some search features in the
 application) we provide the following operations:
\layout LyX-Code

bool hasQuerySettings( uint querySettings );
\layout LyX-Code

uint querySettings();
\layout Standard

The first operation 
\begin_inset Quotes gld
\end_inset 

hasQuerySettings()
\begin_inset Quotes grd
\end_inset 

 may be used to ask whether the database can handle the given query settings.
 In this example a call to 
\layout LyX-Code

hasQuerySettings( OPimBase::WildCards | OpimBase::IgnoreCase );
\layout Standard

should be answered with 
\begin_inset Quotes gld
\end_inset 

true
\begin_inset Quotes grd
\end_inset 

.
 If you need to ask which kind of queries are supported, the operation 
\begin_inset Quotes gld
\end_inset 

querySettings()
\begin_inset Quotes grd
\end_inset 

 will be your friend.
 It will return an unsigned integer value where a 
\begin_inset Quotes gld
\end_inset 

1
\begin_inset Quotes grd
\end_inset 

 is set for every available feature.
\layout Standard

The last parameter is called 
\begin_inset Quotes gld
\end_inset 

startperiod
\begin_inset Quotes grd
\end_inset 

 which is used to set a time interval: 
\layout Standard

In some cases, a time interval should be set to find for instance all entries
 between two dates (used for example by the birthday reminder for today
 (see here: 
\begin_inset LatexCommand \url{http://handhelds.org/cgi-bin/cvsweb.cgi/opie/core/pim/today/plugins/addressbook/addresspluginwidget.cpp?rev=1.14&content-type=text/x-cvsweb-markup}

\end_inset 

)) as requested by the setting 
\begin_inset Quotes gld
\end_inset 

OPimBase::DateDiff
\begin_inset Quotes grd
\end_inset 

.
 The date and time in the query object is used as the 
\series bold 
end
\series default 
 of the interval.
 The start will be defined by the last parameter (if nothing is set, the
 current date will be taken!).
 Therefore, it is possible to set a time frame for all searched entries.
\layout Standard

If you want to do incremental search operations, you may use the special
 
\begin_inset Quotes gld
\end_inset 

queryByExample()
\begin_inset Quotes grd
\end_inset 

 which takes a 
\begin_inset Quotes gld
\end_inset 

List
\begin_inset Quotes grd
\end_inset 

 as the first parameter.
 The search operation will just occur on this set of uid's!
\layout Subsection

Sorting
\layout Standard

To sort a given dataset, you should use the following operation (or one
 of the others which behave slightly differently):
\layout LyX-Code

List sorted (const List& list, bool ascending, int sortOrder, int sortFilter,
 const QArray< UID >& cats);
\layout Standard

This sort operation takes a list of uid's as returned for instance from
 a search query.
 The parameter 
\begin_inset Quotes gld
\end_inset 

ascending
\begin_inset Quotes grd
\end_inset 

 defines whether the sort should be in an ascending order or not.
 
\begin_inset Quotes gld
\end_inset 

sortOrder
\begin_inset Quotes grd
\end_inset 

 is defined by the enumerations 
\begin_inset Quotes gld
\end_inset 

SortOrder
\begin_inset Quotes grd
\end_inset 

 and 
\begin_inset Quotes gld
\end_inset 

SortOrderBase
\begin_inset Quotes grd
\end_inset 

 and defines which field should be used to sort (see for 
\series bold 
OPimContactAccess
\series default 
: 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimContactAccess.html}

\end_inset 

, for 
\series bold 
ODateBookAccess
\series default 
: 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1ODateBookAccess.html}

\end_inset 

 and for 
\series bold 
OPimTodoAccess
\series default 
: 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/classOpie_1_1OPimTodoAccess.html}

\end_inset 

 and for common settings 
\begin_inset LatexCommand \url{http://www.sra.uni-hannover.de/~eilers/apidocs/pim2/html/structOpie_1_1OPimBase.html#w21}

\end_inset 

).
\layout Standard

The 
\begin_inset Quotes gld
\end_inset 

sortFilter
\begin_inset Quotes grd
\end_inset 

 parameter allows to remove some entries which are not interesting for the
 result and is defined in the same classes as 
\begin_inset Quotes gld
\end_inset 

sortOrder
\begin_inset Quotes grd
\end_inset 

 by the enumeration 
\begin_inset Quotes gld
\end_inset 

SortFilter
\begin_inset Quotes grd
\end_inset 

 and 
\begin_inset Quotes gld
\end_inset 

SortFilterBase
\begin_inset Quotes grd
\end_inset 

.
 The list of id's in 
\begin_inset Quotes gld
\end_inset 

cats
\begin_inset Quotes grd
\end_inset 

 allows to remain just these entries which are included in the list of categorie
s.
\layout Standard

The returned list contains the same uid's as given via 
\begin_inset Quotes gld
\end_inset 

list
\begin_inset Quotes grd
\end_inset 

 (or a subset of it, as the sortFilter and category list removes some entries)
 with a modified order as 
\begin_inset Quotes gld
\end_inset 

sortOrder
\begin_inset Quotes grd
\end_inset 

 and 
\begin_inset Quotes gld
\end_inset 

ascending
\begin_inset Quotes grd
\end_inset 

 dictates.
\layout Standard

Therefore 
\begin_inset Quotes gld
\end_inset 

sorted()
\begin_inset Quotes grd
\end_inset 

 is more a combination of search and sort, as just a sort command.
 But this combination is exactly what the developer needs in most situations.
 
\layout Section

Generic Access: OPimBase and OPimRecord
\begin_inset LatexCommand \label{sec:Generic-Access:-OPimBase}

\end_inset 


\layout Section

Caching
\layout Standard

Need to be written.
 Implementation is found at: 
\begin_inset LatexCommand \url{http://handhelds.org/cgi-bin/cvsweb.cgi/opie/noncore/tools/pimconverter/converter.cpp?rev=1.9&content-type=text/x-cvsweb-markup}

\end_inset 


\layout Section

Internal Signal Handling: Automatic Propagation of Changes
\begin_inset LatexCommand \label{sec:Internal-Signal-Handling:}

\end_inset 


\layout Standard

Need to be written and is not implemented completely!
\layout Chapter

Howto Extend and Write New Backends
\layout Standard

Need to be written.
\the_end