PyQGIS: Signal for handling multiple QgsVectorLayer changes at once or on "Save for All Layers"

Question

Is there a signal that I can listen for changes to any QgsVectorLayers rather than having a listener for each layer? I have a scenario where layer A and B must be committed together which I have a validation logic within the method.

When I make changes to QgsVectorLayer and save the layer, I can listen for such event via signals like QgsVectorLayer.beforeCommitChanges(..).

When I make changes to multiple QgsVectorLayers, I receive multiple beforeCommitChanges signal for each affected layer. Instead, I want a way to derive single signal which contain all affected layers.

Answer 1

You can listen on the action when clicking on the button. You need to choose "No" or "Yes" to see the output. PS: not sure it perfectly fit what you need but it may help.

action = iface.mainWindow().findChildren(QAction, 'mActionSaveAllEdits')[0]

def listLayers(bool):
    root = QgsProject.instance().layerTreeRoot()
    layerNodes = []
    # Not recursive here. You may need to add the behavior if layers nested
    for child in root.children():
        if isinstance(child, QgsLayerTreeLayer):
            layerNodes.append(child)
    if QgsLayerTreeUtils.layersModified(layerNodes):
        print([layerNode.layer().name() for layerNode in layerNodes if layerNode.layer().isModified()])

# action.triggered.disconnect(listLayers)
action.triggered.connect(listLayers)