pyqgis - Checking/unchecking rule-visibility of layers at once in QGIS

I've got several rule-based layers in my project (qgis 2.18.13). Is it possible to check/uncheck the visibility of all rules (not the visibility of the layer itself) at once? If yes - is it possible to do this on all layers of the project at once too?

Answer

You could use something like the following to check or uncheck all rule-based style categories from all layers loaded in your project:

from PyQt4.QtCore import Qt

for layer in QgsMapLayerRegistry.instance().mapLayers().values():
    renderer  = layer.rendererV2()
    if renderer.type() == 'RuleRenderer':
        ltl = QgsProject.instance().layerTreeRoot().findLayer(layer.id())
        ltm = iface.layerTreeView().model()
        legendNodes = ltm.layerLegendNodes(ltl)
        for ln in legendNodes:
            ln.setData(Qt.Unchecked, Qt.CheckStateRole)

            #ln.setData(Qt.Checked, Qt.CheckStateRole)