Controller::curr() should return null instead of throwing an exception

[GuySartorelli]

Controller::curr() currently throws an exception if there's no current controller. This means you have to use Controller::has_curr() any time you want to call curr() - when a null return value would do just as well.

Related issues

• Reduce static coupling to Controller::has_curr() and Controller::curr() #4484

Acceptance Criteria

• Controller::curr() returns null if there's no current controller (instead of throwing an exception).
• Make a decision during implementation is Controller::has_curr() should be removed or not

CMS 5 PRs

• API Deprecate Controller::has_curr() #11614
• DOC Deprecate Controller::has_curr() developer-docs#694

After merging assign back to Steve to merge-up and rebase

CMS 6 kitchen sink CI

• https://github.com/creative-commoners/recipe-kitchen-sink/actions/runs/13319224317

CMS 6 PRs

• API Do not raise user_error from Controller::curr() #11613
• ENH Stop using Controller::has_curr() silverstripe-elemental#1318
• ENH Stop using Controller::has_curr() silverstripe-admin#1901
• ENH Stop using Controller::has_curr() silverstripe-blog#807
• ENH Stop using Controller::has_curr() developer-docs#693
• ENH Stop using Controller::has_curr() silverstripe-errorpage#132
• ENH Stop using Controller::has_curr() silverstripe-graphql#626
• ENH Stop using Controller::has_curr() silverstripe-gridfieldqueuedexport#132
• ENH Stop using Controller::has_curr() silverstripe-mfa#588
• ENH Stop using Controller::has_curr() silverstripe-realme#176
• ENH Stop using Controller::has_curr() silverstripe-session-manager#233
• ENH Stop using Controller::has_curr() silverstripe-sharedraftcontent#274
• ENH Stop using Controller::has_curr() silverstripe-subsites#630
• ENH Stop using Controller::has_curr() silverstripe-userforms#1370
• ENH Stop using Controller::has_curr() silverstripe-versioned#492
• ENH Stop using Controller::has_curr() symbiote/silverstripe-queuedjobs#459
• ENH Stop using Controller::has_curr() tractorcow-farm/silverstripe-fluent#928

[GuySartorelli]

@emteknetnz NEeds a CMS 6 changelog entry - lots of people will have

if (Controller::has_curr()) {
    $controller = Controller::curr();
    // do something with controller
}

and they'll need to change that now to something like

$controller = Controller::curr();
if ($controller) {
    // do something with controller
}

[emteknetnz]

Updated

[GuySartorelli]

PRs merged