Support exporting custom "Options/Select" fields to Excel/JSON/CSV/etc

Summary:
See <https://discourse.phabricator-community.org/t/exporting-custom-select-fields-as-part-of-query-exports/2466/>.

In JSON, export both the internal key and the visible value. For other formats, export the visible label.

Test Plan:
  - Added a custom options/select field.
  - Exported CSV, JSON, Text, got sensible output.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D20316

src/__phutil_library_map__.php

@@ -3692,6 +3692,7 @@ phutil_register_library_map(array(
     'PhabricatorOlderInlinesSetting' => 'applications/settings/setting/PhabricatorOlderInlinesSetting.php',
     'PhabricatorOneTimeTriggerClock' => 'infrastructure/daemon/workers/clock/PhabricatorOneTimeTriggerClock.php',
     'PhabricatorOpcodeCacheSpec' => 'applications/cache/spec/PhabricatorOpcodeCacheSpec.php',
+    'PhabricatorOptionExportField' => 'infrastructure/export/field/PhabricatorOptionExportField.php',
     'PhabricatorOptionGroupSetting' => 'applications/settings/setting/PhabricatorOptionGroupSetting.php',
     'PhabricatorOwnerPathQuery' => 'applications/owners/query/PhabricatorOwnerPathQuery.php',
     'PhabricatorOwnersApplication' => 'applications/owners/application/PhabricatorOwnersApplication.php',
@@ -9687,6 +9688,7 @@ phutil_register_library_map(array(
     'PhabricatorOlderInlinesSetting' => 'PhabricatorSelectSetting',
     'PhabricatorOneTimeTriggerClock' => 'PhabricatorTriggerClock',
     'PhabricatorOpcodeCacheSpec' => 'PhabricatorCacheSpec',
+    'PhabricatorOptionExportField' => 'PhabricatorExportField',
     'PhabricatorOptionGroupSetting' => 'PhabricatorSetting',
     'PhabricatorOwnerPathQuery' => 'Phobject',
     'PhabricatorOwnersApplication' => 'PhabricatorApplication',

src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldSelect.php

@@ -153,4 +153,9 @@ final class PhabricatorStandardCustomFieldSelect
       ->setOptions($this->getOptions());
   }
 
+  protected function newExportFieldType() {
+    return id(new PhabricatorOptionExportField())
+      ->setOptions($this->getOptions());
+  }
+
 }

src/infrastructure/export/field/PhabricatorOptionExportField.php

@@ -0,0 +1,47 @@
+<?php
+
+final class PhabricatorOptionExportField
+  extends PhabricatorExportField {
+
+  private $options;
+
+  public function setOptions(array $options) {
+    $this->options = $options;
+    return $this;
+  }
+
+  public function getOptions() {
+    return $this->options;
+  }
+
+  public function getNaturalValue($value) {
+    if ($value === null) {
+      return $value;
+    }
+
+    if (!strlen($value)) {
+      return null;
+    }
+
+    $options = $this->getOptions();
+
+    return array(
+      'value' => (string)$value,
+      'name' => (string)idx($options, $value, $value),
+    );
+  }
+
+  public function getTextValue($value) {
+    $natural_value = $this->getNaturalValue($value);
+    if ($natural_value === null) {
+      return null;
+    }
+
+    return $natural_value['name'];
+  }
+
+  public function getPHPExcelValue($value) {
+    return $this->getTextValue($value);
+  }
+
+}