Run QGIS layer Action on all selected features

Question

QGIS is such an amazing tool with lots of useful features, so that it's easy to overlook some of them.

Just to be sure it's not already implemented in QGIS 2.18:

Is there any Attribute Table option to run a layer Action on all currently selected features?

I'm using a Processing script as workaround, but it would be nice to have this feature directly implemented in the Attribute Table.

##MyTools=group
##VectorLayer=vector
##action_name=string
from qgis.core import *
import qgis.utils
from qgis.gui import *

layer = processing.getObject(VectorLayer)
actionManager = layer.actions()
actions = actionManager.listActions()
if len(actions) > 0:
    cont = False
    i = -1
    for a in actions:
        i = i+1
        if a.name() == action_name:
            cont = True
            break

    if cont:
        selFeatures = layer.selectedFeatures()
        if len(selFeatures) > 0:
            for feature in selFeatures:
                actionManager.doActionFeature(0,feature)
        else:
            qgis.utils.iface.messageBar().pushMessage("Processing Error"," No features selected.",level= QgsMessageBar.WARNING,duration=5)
    else:
        qgis.utils.iface.messageBar().pushMessage("Processing Error"," Wrong layer action defined.",level= QgsMessageBar.WARNING,duration=5)
else:
    qgis.utils.iface.messageBar().pushMessage("Processing Error"," No layer action found.",level= QgsMessageBar.WARNING,duration=5)

Answer 1

You can create and run various actions from the Attribute Table for each feature. If you go to Layer Properties > Actions and add a new action, there is an option which allows you to run the action from the attribute table:

Once you have created an action, you can choose to show it as a combo box:

Now when you open your attribute table, you can see a new field containing the actions:

If you want your action to be run on multiple selected features, you will need to include this into your action (if possible). In my example, I am using Python to print the values from the first field for all selected features. So if I select multiple features and then click on any action combo box, it will print the values of the selected features:

---

However, there seems to be a Run layer action when you right-click an attribute but unfortunately, I can't seem to find much information concerning this. I have posted this as a new question as I am also curious:

What is this 'Run layer action' and how to use it?