Add a way to execute a function in the context of a specific workspace

+++ b/core/modules/workspace/src/WorkspaceManager.php
@@ -200,6 +200,25 @@ public function setActiveWorkspace(WorkspaceInterface $workspace) {
+    $previous_active_workspace = $this->activeWorkspace;
+    $this->activeWorkspace = $workspace;
...
+    $this->activeWorkspace = $previous_active_workspace;

I think this should use the getActiveWorkspace() and setActiveWorkspace() methods, then we can remove the duplicate access check too.

Wouldn't we want it to persist until we switch it back :)

Yes, that is what I had in mind:

We absolutely need to use something like setActiveWorkspace though, because we for example need to clear the (in-memory) entity cache before switching.

See:

cps_override_changeset()

I however don't think we should inform negotiators of a changed workspace - as that really should not persist - even if the operation inside errors out (unexpected to the user).

+++ b/core/modules/workspaces/src/WorkspaceManager.php
@@ -200,6 +202,25 @@ public function setActiveWorkspace(WorkspaceInterface $workspace) {
+    return $this;

Shouldn't it return here what $function() returns?

Looks good.

This would have been a neat area that #2982949: Introduce CallableResolver to help standardise the DX and error handling for callbacks across various subsystems could have helped provide some utility. Vanilla callables need bridges to container injected classes to be unit testable. That's stalled for now though, so this issue is fine as it is.

+++ b/core/modules/workspaces/tests/src/Kernel/WorkspaceIntegrationTest.php
@@ -491,6 +499,57 @@ public function testDisallowedEntityCRUDInNonDefaultWorkspace() {
+    $this->assertEquals([3 => 3], $result);

can we use $(live|stage)_node->(revisionId|id)() here to avoid fragility in the test and make it explicit what these integers represent?

+++ b/core/modules/workspaces/src/WorkspaceManager.php
@@ -166,7 +166,7 @@ public function getActiveWorkspace() {
-  public function setActiveWorkspace(WorkspaceInterface $workspace) {
+  public function setActiveWorkspace(WorkspaceInterface $workspace, $persist = TRUE) {

Are we sure that we want to expose the persist option as API? I think that might lead to errors.

This is currently blocking #2998414: Workspaces fails to deploy content in fields that required dedicated table storage.

+++ b/core/modules/workspaces/src/WorkspaceManager.php
@@ -200,6 +202,25 @@ public function setActiveWorkspace(WorkspaceInterface $workspace) {
+    $this->setActiveWorkspace($workspace, FALSE);
...
+    $this->setActiveWorkspace($previous_active_workspace, FALSE);

I'm with alexpott on this. Let's not make persist part of the public API until we have a need for it.

We can make the elements of setActiveWorkspace that do the switching (but not the persisting) a separate protected function (such as doSwitchWorkspace) and then call that from executeInWorkspace, that way we keep the surface smaller

Committed bc3348b and pushed to 8.7.x. Thanks!

Yeah as an experimental module we should backport this.