[data views] Consolidate code that gets ui settings (#178033)

## Summary

Simple code cleanup. Consolidate UI Setting access and make available
with method in Data Views service.

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

src/plugins/data_views/common/constants.ts

@@ -71,3 +71,5 @@ export const FIELDS_PATH = '/internal/data_views/fields';
 export const EXISTING_INDICES_PATH = '/internal/data_views/_existing_indices';
 
 export const DATA_VIEWS_FIELDS_EXCLUDED_TIERS = 'data_views:fields_excluded_data_tiers';
+
+export const DEFAULT_DATA_VIEW_ID = 'defaultIndex';

src/plugins/data_views/common/data_views/data_views.ts

@@ -12,6 +12,7 @@ import { castEsToKbnFieldTypeName } from '@kbn/field-types';
 import { FieldFormatsStartCommon, FORMATS_UI_SETTINGS } from '@kbn/field-formats-plugin/common';
 import { v4 as uuidv4 } from 'uuid';
 import { PersistenceAPI } from '../types';
+import { DEFAULT_DATA_VIEW_ID } from '../constants';
 
 import type { RuntimeField, RuntimeFieldSpec, RuntimeType } from '../types';
 import { DataView } from './data_view';
@@ -294,6 +295,9 @@ export interface DataViewsServicePublicMethods {
    * Returns whether a default data view exists.
    */
   defaultDataViewExists: () => Promise<boolean>;
+
+  getMetaFields: () => Promise<string[] | undefined>;
+  getShortDotsEnable: () => Promise<boolean | undefined>;
 }
 
 /**
@@ -483,7 +487,7 @@ export class DataViewsService {
    * Get default index pattern id
    */
   getDefaultId = async (): Promise<string | null> => {
-    const defaultIndexPatternId = await this.config.get<string | null>('defaultIndex');
+    const defaultIndexPatternId = await this.config.get<string | null>(DEFAULT_DATA_VIEW_ID);
     return defaultIndexPatternId ?? null;
   };
 
@@ -493,8 +497,8 @@ export class DataViewsService {
    * @param force set default data view even if there's an existing default
    */
   setDefault = async (id: string | null, force = false) => {
-    if (force || !(await this.config.get('defaultIndex'))) {
-      await this.config.set('defaultIndex', id);
+    if (force || !(await this.getDefaultId())) {
+      await this.config.set(DEFAULT_DATA_VIEW_ID, id);
     }
   };
 
@@ -505,13 +509,18 @@ export class DataViewsService {
     return this.apiClient.hasUserDataView();
   }
 
+  getMetaFields = async () => await this.config.get<string[]>(META_FIELDS);
+
+  getShortDotsEnable = async () =>
+    await this.config.get<boolean>(FORMATS_UI_SETTINGS.SHORT_DOTS_ENABLE);
+
   /**
    * Get field list by providing { pattern }.
    * @param options options for getting field list
    * @returns FieldSpec[]
    */
   getFieldsForWildcard = async (options: GetFieldsOptions): Promise<FieldSpec[]> => {
-    const metaFields = await this.config.get<string[]>(META_FIELDS);
+    const metaFields = await this.getMetaFields();
     const { fields } = await this.apiClient.getFieldsForWildcard({
       ...options,
       metaFields,
@@ -542,7 +551,7 @@ export class DataViewsService {
     dataView: DataView,
     forceRefresh: boolean = false
   ) => {
-    const metaFields = await this.config.get<string[]>(META_FIELDS);
+    const metaFields = await this.getMetaFields();
     return this.apiClient.getFieldsForWildcard({
       type: dataView.type,
       rollupIndex: dataView?.typeMeta?.params?.rollup_index,
@@ -555,7 +564,7 @@ export class DataViewsService {
   };
 
   private getFieldsAndIndicesForWildcard = async (options: GetFieldsOptions) => {
-    const metaFields = await this.config.get<string[]>(META_FIELDS);
+    const metaFields = await this.getMetaFields();
     return this.apiClient.getFieldsForWildcard({
       pattern: options.pattern,
       metaFields,
@@ -790,7 +799,7 @@ export class DataViewsService {
       spec.title as string,
       {
         pattern: title as string,
-        metaFields: await this.config.get(META_FIELDS),
+        metaFields: await this.getMetaFields(),
         type,
         rollupIndex: typeMeta?.params?.rollup_index,
         allowNoIndex: spec.allowNoIndex,
@@ -957,8 +966,8 @@ export class DataViewsService {
     skipFetchFields = false,
     displayErrors = true
   ): Promise<DataView> {
-    const shortDotsEnable = await this.config.get<boolean>(FORMATS_UI_SETTINGS.SHORT_DOTS_ENABLE);
-    const metaFields = await this.config.get<string[] | undefined>(META_FIELDS);
+    const shortDotsEnable = await this.getShortDotsEnable();
+    const metaFields = await this.getMetaFields();
 
     const spec = {
       id: id ?? uuidv4(),
@@ -1193,21 +1202,21 @@ export class DataViewsService {
 
   private async getDefaultDataViewId() {
     const patterns = await this.getIdsWithTitle();
-    let defaultId: string | undefined = await this.config.get('defaultIndex');
+    let defaultId: string | null = await this.getDefaultId();
     const exists = defaultId ? patterns.some((pattern) => pattern.id === defaultId) : false;
 
     if (defaultId && !exists) {
       if (await this.getCanSaveAdvancedSettings()) {
-        await this.config.remove('defaultIndex');
+        await this.config.remove(DEFAULT_DATA_VIEW_ID);
       }
 
-      defaultId = undefined;
+      defaultId = null;
     }
 
     if (!defaultId && patterns.length >= 1 && (await this.hasUserDataView().catch(() => true))) {
       defaultId = patterns[0].id;
       if (await this.getCanSaveAdvancedSettings()) {
-        await this.config.set('defaultIndex', defaultId);
+        await this.config.set(DEFAULT_DATA_VIEW_ID, defaultId);
       }
     }