Allow sorting and filtering on _type field (#10311)

Backports PR #10254

It was already possible to sort, aggregate, and filter on _type in ES but we didn't allow it in Kibana because Elasticsearch's APIs pre-5.0 didn't report mapping information for meta fields. Now that field stats returns searchable and aggregatable (including meta fields) we can safely determine if any field is filterable, sortable, or aggregatable without looking at the mappings. This PR simply includes the searchable and aggregatable information in the calculations that determine filterable and sortable status of a field.

src/core_plugins/kibana/public/discover/components/field_chooser/discover_field.js

@@ -39,7 +39,7 @@ app.directive('discoverField', function ($compile) {
               ' Values such as foo-bar will be broken into foo and bar.');
           }
 
-          if (!field.indexed) {
+          if (!field.indexed && !field.searchable) {
             warnings.push('This field is not indexed and might not be usable in visualizations.');
           }
         }

src/fixtures/logstash_fields.js

@@ -25,6 +25,8 @@ function stubbedLogstashFields() {
     ['_id',               'string',     false, false, true,  true ],
     ['_type',             'string',     false, false, true,  true ],
     ['_source',           'string',     false, false, true,  true ],
+    ['non-filterable',    'string',     false, false, true,  false],
+    ['non-sortable',      'string',     false, false, false, false],
     ['custom_user_field', 'conflict',   false, false, true,  true ],
     ['script string',     'string',     false, false, true,  false, { script: '\'i am a string\'' } ],
     ['script number',     'number',     false, false, true,  false, { script: '1234' } ],

src/ui/public/doc_table/__tests__/lib/get_sort.js

@@ -25,11 +25,11 @@ describe('docTable', function () {
     });
 
     it('should sort by the default when passed an unsortable field', function () {
-      expect(getSort(['_id', 'asc'], indexPattern)).to.eql(defaultSort);
+      expect(getSort(['non-sortable', 'asc'], indexPattern)).to.eql(defaultSort);
       expect(getSort(['lol_nope', 'asc'], indexPattern)).to.eql(defaultSort);
 
       delete indexPattern.timeFieldName;
-      expect(getSort(['_id', 'asc'], indexPattern)).to.eql({ _score: 'desc' });
+      expect(getSort(['non-sortable', 'asc'], indexPattern)).to.eql({ _score: 'desc' });
     });
 
     it('should sort in reverse chrono order otherwise on time based patterns', function () {

src/ui/public/filter_bar/__tests__/filter_bar_click_handler.js

@@ -26,7 +26,7 @@ describe('filterBarClickHandler', function () {
           {
             type: 'terms',
             schema: 'segment',
-            params: { field: '_type' }
+            params: { field: 'non-filterable' }
           }
         ]
       });

src/ui/public/index_patterns/_field.js

@@ -40,10 +40,10 @@ export default function FieldObjectProvider(Private, shortDotsFilter, $rootScope
 
     const indexed = !!spec.indexed;
     const scripted = !!spec.scripted;
-    const sortable = spec.name === '_score' || ((indexed || scripted) && type.sortable);
-    const filterable = spec.name === '_id' || scripted || (indexed && type.filterable);
     const searchable = !!spec.searchable || scripted;
     const aggregatable = !!spec.aggregatable || scripted;
+    const sortable = spec.name === '_score' || ((indexed || aggregatable) && type.sortable);
+    const filterable = spec.name === '_id' || scripted || ((indexed || searchable) && type.filterable);
     const visualizable = aggregatable;
 
     obj.fact('name');