Add documentation to the ES service.

src/app/elasticsearch/services/elasticsearch.service.ts

@@ -8,6 +8,11 @@ import { APP_CONFIG } from '../../core/services/app-config.service';
 import { scopesResearch } from '../../shared/variables';
 import { Aggregation, ElasticsearchOptions, Filter, IElasticsearchResponse, IPostsESOptions } from '../models';
 
+/*
+  This service is in charge to get the content from Elasticsearch. This includes
+  all the metadata and data from datasets
+*/
+
 @Injectable()
 export class ElasticsearchService {
 
@@ -23,10 +28,9 @@ export class ElasticsearchService {
   }
 
   /**
-   *  This is the main elasticsearch (ES) request to get information from ES indexes
-   *  We have one ES options as parameter used for 2 purposes:
-   *  - to construct the request options:  research, sorting, paginations, highlight, etc...
-   *  - to know in which indexes we will search: datasets, articles or both
+   *  This is the main elasticsearch (ES) request to get information from ES
+   *  We have one ES options as parameter used for multiple purposes:
+   *  - research, sorting, paginations, highlight, etc...
    */
   getAllEntities(options: ElasticsearchOptions): Observable<IElasticsearchResponse> {
     const requestOptions = this.constructElasticsearchRequest(options);
@@ -43,6 +47,7 @@ export class ElasticsearchService {
     );
   }
 
+  // Get the metadata. For this reason we add the 'metadata-fr' source where all the metadata content is.
   getDatasetMetadata(slugOrUuid: string): Observable<IElasticsearchResponse> {
     return this._http.request<IElasticsearchResponse>('POST', this.elasticSearchUrl, {
       withCredentials: true,
@@ -76,6 +81,8 @@ export class ElasticsearchService {
     );
   }
 
+  // Each dataset have one unique slug and uuid. This method get the slugs
+  // from a list of uuids. (this is useful for routing purpose for example)
   getSlugsFromUuid(uuids: string[]): Observable<IElasticsearchResponse> {
     return this._http.request<IElasticsearchResponse>('POST', this.elasticSearchUrl, {
       body: {
@@ -100,10 +107,15 @@ export class ElasticsearchService {
     );
   }
 
+  // This retrieves the data of a dataset. The query is done by uuid.
   getDatasetData(id: number | string, options?: ElasticsearchOptions): Observable<IElasticsearchResponse> {
+
+    // Set the pagination
     const from = options ? options.from : 0;
     const size = options ? options.pageSize : 10;
 
+    // Retrieve only the data (not the editorial-metadata, metadata, etc..)
+    // This is done by setting 'data-fr' as _source.
     const body = {
       from,
       size,
@@ -126,13 +138,14 @@ export class ElasticsearchService {
       body['sort'] = [sort];
     }
 
+    // Here the default_field is 'data', meaning that the query 
     if (options.searchString !== '') {
       const searchString = this.escapeSpecialCharacters(options.searchString, options.fromAutocompletion, 'AND');
       body.query.bool['must'] = [
         {
           query_string: {
             query: searchString,
-            default_field: '*.mapbox',
+            default_field: 'data',
             analyzer: 'my_search_analyzer',
             fuzziness: 'AUTO',
             minimum_should_match: '90%',
@@ -141,6 +154,9 @@ export class ElasticsearchService {
       ];
     }
 
+    // This is an option to use an nginx cache or not.
+    // We usually use it, except for real time data when you want all the time the
+    // latest and more fresh data.
     const headers = options.useCache ? {} : { nocache: 'True' };
 
     return this._http.request<IElasticsearchResponse>('POST', this.elasticSearchUrl, {
@@ -165,7 +181,7 @@ export class ElasticsearchService {
       .replace(/\&\&/g, '\\&&'); // replace &&
 
     const request = {
-      _source: false,
+      _source: false, // We need only the highlight, not the hits
       query: {
         bool: {
           must: [
@@ -185,6 +201,7 @@ export class ElasticsearchService {
             minimum_should_match: '90%',
           },
         },
+        // Rules to construct the highlight fragments
         fields: {
           '*data-fr.*': {
             fragment_size: 50,
@@ -235,7 +252,7 @@ export class ElasticsearchService {
           suggestion: {
             phrase: {
               field: 'data_and_metadata.suggest',
-              // as only the very first suggestion will be used, let's limit the size of the results to 1:
+              // as only the very first suggestion will be used, let's limit the size of the results to 1
               size: 1,
               max_errors: query.split(' ').length,
               highlight: {