All reports are processed by advancing from one report state to another state.
Reporting always starts with a start state and ends with a finish state.
Whenever a state advances, the internal state of the state-object should change.
If the internal state does not change, the process is caught in an infinite loop
and must be interrupted. State-advances are tested by using the
ReportState.isProceeding method.
Some report states fire events when they advance into another state. These events are
used to inform the report-functions that a certain report processing level has been
reached. The only valid receiver of ReportEvents are Expressions and Functions.
Start-State
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The start state is the first state of the report processing process and the only state
that can be created without having a previous state.
Events fired:
During the advance process, a ReportEvent is fired to inform the state-clients that
the report processing has started. ReportListener.reportStarted (ReportEvent) is called
for all registered listeners.
Advances to:
This state advances into the PreGroupHeader state.
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PreGroupHeader-State
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The PreGroupHeader marks the beginning of a new group. When this state advances,
the group is activated and the groupheader of this group should be processed. The
system will activate all defined groups before starting to process the items.
Events fired:
During the advance process, a ReportEvent is fired to inform the state-clients that
a new group has started. ReportListener.groupStarted (ReportEvent) is called
for all registered listeners. The currently active group can be queried by using
ReportState.getCurrentGroupIndex().
Advances to:
This state advances into the PostGroupHeader state.
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PostGroupHeader-State
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If there are more groups to activate for the current report, the PostGroupHeader will
activate those groups by advancing into a new PreGroupHeader state. If all groups are
activated, the PostGroupHeader-state will start the ItemProcessing by advancing into
a PreItemGroup state.
Events fired:none
Advances to:Either PreGroupHeader or PreItemGroup state.
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PreItemGroup-State
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This state is used to inform every listener that the ItemProcessing is about to start.
At this moment, all groups have been activated. On advance, the ItemStarted event is fired.
If there is at least one row to print, this state advances into InItemGroup-state, else
this state continues at the PostItemGroup state. The direct advancement into PostItemGroup
should only happen if the given TableModel does not contain any rows.
Events fired:ItemStarted
Advances to:Either InItemGroup or PostItemGroup state.
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InItemGroup-State
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The report engine is now processing the group items. When advancing, a ItemsAdvanced
event is fired. Then state advances into a
InItemGroup state as long as the current group is valid and the end of the report
has not been reached. A group is valid as long as the contents of the fields assigned
to the group do not change. As long as the group is valid, this state advances to
InItemGroup-state and increases the current row of the DataRow. If the group is no
longer valid, this state advances into a PostItemGroup state.
Events fired:ItemsAdvanced. The datarow is automaticly adjusted to reflect
the new row. The current row number can be queried by using ReportState.getCurrentRow().
Advances to:Either PostItemGroup or InItemGroup state.
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PostItemGroup-State
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This state is used to inform every listener that the ItemProcessing is now finished.
The advancing will fire the ItemsFinished event and then proceed to PreGroupFooter.
Events fired:ItemsFinished
Advances to:PreGroupFooter
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PreGroupFooter-State
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The current group is now finished. The GroupFooter should be printed. This state
fires the GroupFinished event and then advances to PostGroupFooter.
Events fired:GroupFinished
Advances to:PostGroupFooter
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PostGroupFooter-State
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This state closes the current group. After that group is closed,
the report engine checks if there are more open groups, which are invalid and should be closed.
A group is valid as long as the contents of the fields assigned to the group do not
change. In this case, the state advances to PreGroupFooter for the to be closed group.
If there is no group that should be closed and there are more rows to process,
the next sub-group is opened and the state advances into PreGroupHeader for the new group.
If there are no more groups active and there are no rows to process, then the report
processing is almost finished and the state advances to PreReportFooter.
Events fired:none
Advances to:PreGroupHeader, PreGroupFooter or PreReportFooter.
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PreReportFooter-State
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Now the report is almost finished. The last task to be done is the processing of the
ReportFooter. On advance the ReportFinished event is fired and then the state advances
into the FinishState.
Events fired:ReportFinished
Advances to:FinishState
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Finish-State
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This state does not advance and fires an ReportProcessingException when it should
advance.
Events fired:none
Advances to:none
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