author | eilers <eilers> | 2005-01-04 14:22:12 (UTC) |
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committer | eilers <eilers> | 2005-01-04 14:22:12 (UTC) |
commit | a63d6d1896bcb6f1ac3b041e3d46edf0ec9e8082 (patch) (side-by-side diff) | |
tree | c5125a96d16685cb49eecb479e761e6b3e9375b3 | |
parent | ff93c49af890b2b03f729a848be36b77a6e2454b (diff) | |
download | opie-a63d6d1896bcb6f1ac3b041e3d46edf0ec9e8082.zip opie-a63d6d1896bcb6f1ac3b041e3d46edf0ec9e8082.tar.gz opie-a63d6d1896bcb6f1ac3b041e3d46edf0ec9e8082.tar.bz2 |
Add section for sorting
-rw-r--r-- | development/pim/pim_howto/pim_howto.lyx | 238 |
1 files changed, 218 insertions, 20 deletions
diff --git a/development/pim/pim_howto/pim_howto.lyx b/development/pim/pim_howto/pim_howto.lyx index 2b08be8..4571996 100644 --- a/development/pim/pim_howto/pim_howto.lyx +++ b/development/pim/pim_howto/pim_howto.lyx @@ -94,77 +94,77 @@ Stefan Eilers \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 calender 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 unneccessary classes and details which - makes the quick start not as easy as expected. - Due to the fact that a user who just want to access data will not need - most of the details, this paper should help to start to be confortable - with the details he need to solve his problems. + 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 specialities - of the PIM API first. + 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 whe have to use them (for instance to use the factory classes) + In some cases whe 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 unneccessary 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. - This paper just focusses the frontend as we just want to access data. + As we just want to access data, this paper just focusses 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 interessting for people who want to extend or implement new possiblities 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! @@ -311,33 +311,33 @@ my-app 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 +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 @@ -410,34 +410,34 @@ 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, - which is done by the +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 @@ -486,33 +486,33 @@ allRecords() 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 +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 identifaction 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 paramter: @@ -570,66 +570,66 @@ 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 dafault backend. Whether this default backend will access the XML, VCard or SQLite database - type, this is defined by the configuration file + 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, he has - to use the oparation +If the developer wants to select a special database type for sure without + unnecessary side effects, he has to use the oparation \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 paramters are already known, like type and appName (see section \begin_inset LatexCommand \ref{sec:Instantiate-the-Access} \end_inset ). @@ -746,33 +746,33 @@ 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 excercise we provide some special operations which provide searching and sorting in an incremental manner \begin_inset Foot collapsed true \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 . - Therfore it is possible to research a + 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 @@ -905,58 +905,67 @@ Eilers \end_inset ); \layout LyX-Code searchQuery.setHomeZip( \begin_inset Quotes gld \end_inset 3* \begin_inset Quotes grd \end_inset ); \layout Standard -We use a usual +We use an usual \begin_inset Quotes gld \end_inset OPimContact \begin_inset Quotes grd \end_inset - and fill into two fields the search information. + 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 for finding files in a filesystem. + 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 @@ -1006,33 +1015,33 @@ WildCards \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 + 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. @@ -1044,33 +1053,33 @@ 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 accesses as usual, +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 true @@ -1160,32 +1169,221 @@ In some cases, a time interval should be set to find for instance all entries \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 occure 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} |