[Qgis-developer] Add multiple frames to a composer attribute table using PyQGIS

[Nyall Dawson]

On 1 November 2015 at 20:09, James Stott <jamesstott1 at gmail.com> wrote:
> I have an attribute table that is around two hundred rows of data (but only
> two columns wide). I would like to add an attribute table to a composer with
> this data, and to do this I need to add multiple frames so I can add the
> whole attribute table to one page. Doing this manually in the composer I
> just add 5 frames side by side to one composer page, and I manage to get all
> my data on one page.
>
> I cannot figure out how to add an attribute table with multiple frames to a
> composer using PyQGIS. I am problably missing something really obvious, but
> I am stuck here.
>
> When I try to define a QgsComposerFrame, I am told that I must specify the
> QgsComposerMultiFrame it belongs to:
>
> QgsComposerFrame (QgsComposition *c, QgsComposerMultiFrame *mf, qreal x,
> qreal y, qreal width, qreal height)
>
> How do I create the QgsComposerMultiFrame. It is an abstract class, I am
> told that it is an abstract class and cannot be instantiated. If I try
>
> multiFrame = QgsComposerMultiFrame(myCompositionTable, False)
>
> I get the following error when I run my code.
>
> qgis._core.QgsComposerMultiFrame represents a C++ abstract class and cannot
> be instantiated

You create a QgsComposerAttributeTableV2 instead, which derives from
QgsComposerMultiFrame. Here's some c++ code which does this, which
should be pretty straightforward to translate to Python:


mComposerAttributeTable = new QgsComposerAttributeTableV2(
mComposition, false );
mComposition->addMultiFrame( mComposerAttributeTable );

mFrame1 = new QgsComposerFrame( mComposition, mComposerAttributeTable,
5, 5, 100, 30 );
mFrame2 = new QgsComposerFrame( mComposition, mComposerAttributeTable,
5, 40, 100, 30 );

mComposerAttributeTable->addFrame( mFrame1 );
mComposerAttributeTable->addFrame( mFrame2 );

mComposition->addComposerTableFrame( mComposerAttributeTable, mFrame1 );
mComposition->addComposerTableFrame( mComposerAttributeTable, mFrame2 );

mComposerAttributeTable->setVectorLayer( mVectorLayer );
mComposerAttributeTable->setDisplayOnlyVisibleFeatures( false );
mComposerAttributeTable->setMaximumNumberOfFeatures( 10 );
mComposerAttributeTable->setContentFont( QgsFontUtils::getStandardTestFont() );
mComposerAttributeTable->setHeaderFont( QgsFontUtils::getStandardTestFont() );
mComposerAttributeTable->setBackgroundColor( Qt::yellow );

When in doubt for something like this and you can't find any examples
online, a good last resort to check is in the QGIS unit tests:
https://github.com/qgis/QGIS/tree/master/tests/src
(or in this case
https://github.com/qgis/QGIS/blob/master/tests/src/core/testqgscomposertablev2.cpp)

They are filled with minimal test cases such as this which are useful
for seeing how various classes are intended to be used.

Nyall




>
> I cant find any documentation or examples on how to do this. So if someone
> could shed some light on this it would be most appreciated. I am happy to
> write up a bit of documentation once I have managed to do this.
>
> Many thanks,
>
> James
>
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