Action
objects let you build interactive
behavior into Google Workspace add-ons. They define
what happens when a user interacts with a widget (for example, a button) in
the add-on UI.
An action is attached to a given widget using a widget handler function , which also defines the condition that triggers the action. When triggered, the action executes a designated callback function . The callback function is passed an event object that carries information about the user's client-side interactions. You must implement the callback function and have it return a specific response object.
For example, say you want a button that builds and displays a new card when
clicked. For this, you must create a new button widget and use the button widget
handler function setOnClickAction(action)
to set a card-building Action
. The Action
you define specifies an Apps Script
callback function that executes when the button is clicked. In this case, you
implement the callback function to build the card you want and return an ActionResponse
object. The response object tells the add-on to display the card the callback
function built.
This page describes Drive-specific widget actions you can include in your add-on.
Drive interactions
Google Workspace add-ons that extend Drive can include an additional Drive-specific widget action. This action requires the associated action callback function to return a specialized response object:
| Action attempted | Callback function should return |
|---|---|
| Request file access for selected files | DriveItemsSelectedActionResponse
|
To make use of these widget actions and response objects, all of the following must be true:
- The action is triggered while the user has one or more Drive items selected.
- The add-on includes the
https://www.googleapis.com/auth/drive.fileDrive scope in its manifest.
Request file access for selected files
The following example shows how to build a contextual interface for Google
Drive that is triggered when the user selects one or more Drive items. The
example tests each item to see if the add-on has been granted access permission;
if not, it uses a DriveItemsSelectedActionResponse
object to request that permission from the user. Once permission is granted for
an item, the add-on displays the Drive quota usage of that item.
/**
*
Build
a
simple
card
that
checks
selected
items
' quota usage. Checking
*
quota
usage
requires
user
-
permissions
,
so
this
add
-
on
provides
a
button
*
to
request
`
drive
.
file
`
scope
for
items
the
add
-
on
doesn
't yet have
*
permission
to
access
.
*
*
@
param
e
The
event
object
passed
containing
contextual
information
about
*
the
Drive
items
selected
.
*
@
return
{
Card
}
*/
function
onDriveItemsSelected
(
e
)
{
var
builder
=
CardService
.
newCardBuilder
();
//
For
each
item
the
user
has
selected
in
Drive
,
display
either
its
//
quota
information
or
a
button
that
allows
the
user
to
provide
//
permission
to
access
that
file
to
retrieve
its
quota
details
.
e
[
'drive'
][
'selectedItems'
]
.
forEach
(
function
(
item
){
var
cardSection
=
CardService
.
newCardSection
()
.
setHeader
(
item
[
'title'
]);
//
This
add
-
on
uses
the
recommended
,
limited
-
permission
`
drive
.
file
`
//
scope
to
get
granular
per
-
file
access
permissions
.
//
See
:
https
:
//
developers
.
google
.
com
/
drive
/
api
/
v2
/
about
-
auth
if
(
item
[
'addonHasFileScopePermission'
])
{
//
If
the
add
-
on
has
access
permission
,
read
and
display
its
//
quota
.
cardSection
.
addWidget
(
CardService
.
newTextParagraph
()
.
setText
(
"This file takes up: "
+
getQuotaBytesUsed
(
item
[
'id'
])));
}
else
{
//
If
the
add
-
on
does
not
have
access
permission
,
add
a
button
//
that
allows
the
user
to
provide
that
permission
on
a
per
-
file
//
basis
.
cardSection
.
addWidget
(
CardService
.
newTextParagraph
()
.
setText
(
"The add-on needs permission to access this file's quota."
));
var
buttonAction
=
CardService
.
newAction
()
.
setFunctionName
(
"onRequestFileScopeButtonClicked"
)
.
setParameters
({
id
:
item
.
id
});
var
button
=
CardService
.
newTextButton
()
.
setText
(
"Request permission"
)
.
setOnClickAction
(
buttonAction
);
cardSection
.
addWidget
(
button
);
}
builder
.
addSection
(
cardSection
);
});
return
builder
.
build
();
}
/**
*
Callback
function
for
a
button
action
.
Instructs
Drive
to
display
a
*
permissions
dialog
to
the
user
,
requesting
`
drive
.
file
`
scope
for
a
*
specific
item
on
behalf
of
this
add
-
on
.
*
*
@
param
{
Object
}
e
The
parameters
object
that
contains
the
item
's
*
Drive
ID
.
*
@
return
{
DriveItemsSelectedActionResponse
}
*/
function
onRequestFileScopeButtonClicked
(
e
)
{
var
idToRequest
=
e
.
parameters
.
id
;
return
CardService
.
newDriveItemsSelectedActionResponseBuilder
()
.
requestFileScope
(
idToRequest
)
.
build
();
}
/**
*
Use
the
Advanced
Drive
Service
*
(
See
https
:
//
developers
.
google
.
com
/
apps
-
script
/
advanced
/
drive
),
*
with
`
drive
.
file
`
scope
permissions
to
request
the
quota
usage
of
a
*
specific
Drive
item
.
*
*
@
param
{
string
}
itemId
The
ID
of
the
item
to
check
.
*
@
return
{
string
}
A
description
of
the
item
's quota usage, in bytes.
*/
function
getQuotaBytesUsed
(
itemId
)
{
try
{
return
Drive
.
Files
.
get
(
itemId
,{
fields
:
"quotaBytesUsed"
})
.
quotaBytesUsed
+
" bytes"
;
}
catch
(
e
)
{
return
"Error fetching how much quota this item uses. Error: "
+
e
;
}
}
