1 | /* |
2 | Copyright (c) 2006-2008 Volker Krause <vkrause@kde.org> |
3 | |
4 | This library is free software; you can redistribute it and/or modify it |
5 | under the terms of the GNU Library General Public License as published by |
6 | the Free Software Foundation; either version 2 of the License, or (at your |
7 | option) any later version. |
8 | |
9 | This library is distributed in the hope that it will be useful, but WITHOUT |
10 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
11 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public |
12 | License for more details. |
13 | |
14 | You should have received a copy of the GNU Library General Public License |
15 | along with this library; see the file COPYING.LIB. If not, write to the |
16 | Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
17 | 02110-1301, USA. |
18 | */ |
19 | |
20 | #ifndef AKONADI_TRANSACTIONSEQUENCE_H |
21 | #define AKONADI_TRANSACTIONSEQUENCE_H |
22 | |
23 | #include "akonadi_export.h" |
24 | |
25 | #include <akonadi/job.h> |
26 | |
27 | namespace Akonadi { |
28 | |
29 | class TransactionSequencePrivate; |
30 | |
31 | /** |
32 | * @short Base class for jobs that need to run a sequence of sub-jobs in a transaction. |
33 | * |
34 | * As soon as the first subjob is added, the transaction is started. |
35 | * As soon as the last subjob has successfully finished, the transaction is committed. |
36 | * If any subjob fails, the transaction is rolled back. |
37 | * |
38 | * Alternatively, a TransactionSequence object can be used as a parent object |
39 | * for a set of jobs to achieve the same behaviour without subclassing. |
40 | * |
41 | * Example: |
42 | * |
43 | * @code |
44 | * |
45 | * // Delete a couple of items inside a transaction |
46 | * Akonadi::TransactionSequence *transaction = new Akonadi::TransactionSequence; |
47 | * connect( transaction, SIGNAL(result(KJob*)), SLOT(transactionFinished(KJob*)) ); |
48 | * |
49 | * const Akonadi::Item::List items = ... |
50 | * |
51 | * foreach ( const Akonadi::Item &item, items ) { |
52 | * new Akonadi::ItemDeleteJob( item, transaction ); |
53 | * } |
54 | * |
55 | * ... |
56 | * |
57 | * MyClass::transactionFinished( KJob *job ) |
58 | * { |
59 | * if ( job->error() ) |
60 | * qDebug() << "Error occurred"; |
61 | * else |
62 | * qDebug() << "Items deleted successfully"; |
63 | * } |
64 | * |
65 | * @endcode |
66 | * |
67 | * @author Volker Krause <vkrause@kde.org> |
68 | */ |
69 | class AKONADI_EXPORT TransactionSequence : public Job |
70 | { |
71 | Q_OBJECT |
72 | public: |
73 | /** |
74 | * Creates a new transaction sequence. |
75 | * |
76 | * @param parent The parent object. |
77 | */ |
78 | explicit TransactionSequence(QObject *parent = 0); |
79 | |
80 | /** |
81 | * Destroys the transaction sequence. |
82 | */ |
83 | ~TransactionSequence(); |
84 | |
85 | /** |
86 | * Commits the transaction as soon as all pending sub-jobs finished successfully. |
87 | */ |
88 | void commit(); |
89 | |
90 | /** |
91 | * Rolls back the current transaction as soon as possible. |
92 | * You only need to call this method when you want to roll back due to external |
93 | * reasons (e.g. user cancellation), the transaction is automatically rolled back |
94 | * if one of its subjobs fails. |
95 | * @since 4.5 |
96 | */ |
97 | void rollback(); |
98 | |
99 | /** |
100 | * Sets which job of the sequence might fail without rolling back the |
101 | * complete transaction. |
102 | * @param job a job to ignore errors from |
103 | * @since 4.5 |
104 | */ |
105 | void setIgnoreJobFailure(KJob *job); |
106 | |
107 | /** |
108 | * Disable automatic committing. |
109 | * Use this when you want to add jobs to this sequence after execution |
110 | * has been started, usually that is outside of the constructor or the |
111 | * method that creates this transaction sequence. |
112 | * @note Calling this method after execution of this job has been started |
113 | * has no effect. |
114 | * @param enable @c true to enable autocommitting (default), @c false to disable it |
115 | * @since 4.5 |
116 | */ |
117 | void setAutomaticCommittingEnabled(bool enable); |
118 | |
119 | protected: |
120 | bool addSubjob(KJob *job); |
121 | void doStart(); |
122 | |
123 | protected Q_SLOTS: |
124 | void slotResult(KJob *job); |
125 | |
126 | private: |
127 | Q_DECLARE_PRIVATE(TransactionSequence) |
128 | |
129 | //@cond PRIVATE |
130 | Q_PRIVATE_SLOT(d_func(), void commitResult(KJob *)) |
131 | Q_PRIVATE_SLOT(d_func(), void rollbackResult(KJob *)) |
132 | //@endcond |
133 | }; |
134 | |
135 | } |
136 | |
137 | #endif |
138 | |