Allow administrators to provide custom welcome text when welcoming users on the profile workflow

Summary:
See PHI1027. Currently, we allow you to customize invite email, but not most other types of email (approve, welcome). As a step forward, also allow welcome email to be customized with a message.

I considered separating the custom text from the main text with something heavyhanded ("alice added this custom message:") or a beautiful ASCII art divider like one of these:

https://www.asciiart.eu/art-and-design/dividers

...but nothing truly sung to me.

This only works on the profile flow for now. I'm planning to let you set a default message. I may or may not let you customize from "Create New User", seems like the default message probably covers most of that. Probably won't touch `scripts/user/add_user.php` since that's not really exactly super supported.

Test Plan:
Sent mail with and without custom messages, reviewed it with `bin/mail show-outbound`.

{F6137410}

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D19991

src/applications/people/controller/PhabricatorPeopleProfileManageController.php

@@ -155,6 +155,18 @@ final class PhabricatorPeopleProfileManageController
       $disable_name = pht('Disable User');
     }
 
+    $curtain->addAction(
+      id(new PhabricatorActionView())
+        ->setIcon('fa-envelope')
+        ->setName(pht('Send Welcome Email'))
+        ->setWorkflow(true)
+        ->setDisabled(!$can_welcome)
+        ->setHref($this->getApplicationURI('welcome/'.$user->getID().'/')));
+
+    $curtain->addAction(
+      id(new PhabricatorActionView())
+        ->setType(PhabricatorActionView::TYPE_DIVIDER));
+
     $curtain->addAction(
       id(new PhabricatorActionView())
         ->setIcon($disable_icon)
@@ -173,11 +185,7 @@ final class PhabricatorPeopleProfileManageController
 
     $curtain->addAction(
       id(new PhabricatorActionView())
-        ->setIcon('fa-envelope')
-        ->setName(pht('Send Welcome Email'))
-        ->setWorkflow(true)
-        ->setDisabled(!$can_welcome)
-        ->setHref($this->getApplicationURI('welcome/'.$user->getID().'/')));
+        ->setType(PhabricatorActionView::TYPE_DIVIDER));
 
     return $curtain;
   }

src/applications/people/controller/PhabricatorPeopleWelcomeController.php

@@ -37,24 +37,45 @@ final class PhabricatorPeopleWelcomeController
         ->addCancelButton($profile_uri, pht('Done'));
     }
 
+    $v_message = $request->getStr('message');
+
     if ($request->isFormPost()) {
+      if (strlen($v_message)) {
+        $welcome_engine->setWelcomeMessage($v_message);
+      }
+
       $welcome_engine->sendMail();
       return id(new AphrontRedirectResponse())->setURI($profile_uri);
     }
 
+    $form = id(new AphrontFormView())
+      ->setViewer($admin)
+      ->appendInstructions(
+        pht(
+          'This workflow will send this user ("%s") a copy of the "Welcome to '.
+          'Phabricator" email that users normally receive when their '.
+          'accounts are created by an administrator.',
+          $user->getUsername()))
+      ->appendInstructions(
+        pht(
+          'The email will contain a link that the user may use to log in '.
+          'to their account. This link bypasses authentication requirements '.
+          'and allows them to log in without credentials. Sending a copy of '.
+          'this email can be useful if the original was lost or never sent.'))
+      ->appendInstructions(
+        pht(
+          'The email will identify you as the sender. You may optionally '.
+          'include additional text in the mail body by specifying it below.'))
+      ->appendControl(
+        id(new AphrontFormTextAreaControl())
+          ->setName('message')
+          ->setLabel(pht('Custom Message'))
+          ->setValue($v_message));
+
     return $this->newDialog()
       ->setTitle(pht('Send Welcome Email'))
-      ->appendParagraph(
-        pht(
-          'This will send the user another copy of the "Welcome to '.
-          'Phabricator" email that users normally receive when their '.
-          'accounts are created.'))
-      ->appendParagraph(
-        pht(
-          'The email contains a link to log in to their account. Sending '.
-          'another copy of the email can be useful if the original was lost '.
-          'or never sent.'))
-      ->appendParagraph(pht('The email will identify you as the sender.'))
+      ->setWidth(AphrontDialogView::WIDTH_FORM)
+      ->appendForm($form)
       ->addSubmitButton(pht('Send Email'))
       ->addCancelButton($profile_uri);
   }

src/applications/people/mail/PhabricatorPeopleWelcomeMailEngine.php

@@ -3,6 +3,17 @@
 final class PhabricatorPeopleWelcomeMailEngine
   extends PhabricatorPeopleMailEngine {
 
+  private $welcomeMessage;
+
+  public function setWelcomeMessage($welcome_message) {
+    $this->welcomeMessage = $welcome_message;
+    return $this;
+  }
+
+  public function getWelcomeMessage() {
+    return $this->welcomeMessage;
+  }
+
   public function validateMail() {
     $sender = $this->getSender();
     $recipient = $this->getRecipient();
@@ -88,9 +99,14 @@ final class PhabricatorPeopleWelcomeMailEngine
       $message[] = pht('  %s', $base_uri);
     }
 
+    $custom_body = $this->getWelcomeMessage();
+    if (strlen($custom_body)) {
+      $message[] = $custom_body;
+    } else {
       if (!$is_serious) {
         $message[] = pht("Love,\nPhabricator");
       }
+    }
 
     $message = implode("\n\n", $message);