data-den-fetch-service.ts

import { Context } from '../../context';
import { DataDenEvent } from '../../data-den-event';
import { DataDenPubSub } from '../../data-den-pub-sub';
import { DataDenFetchDoneEvent } from './data-den-fetch-done.event.interface';
import { DataDenFetchOptions } from './data-den-fetch-options.interface';
import { DataDenDataLoaderStrategy } from './strategy/data-den-data-loader-strategy';
import { DataDenEventEmitter } from '../../data-den-event-emitter';

export class DataDenFetchService {
  #loader: DataDenDataLoaderStrategy;
  #fetchOptions: DataDenFetchOptions;

  constructor(loader: DataDenDataLoaderStrategy, private PubSub: DataDenPubSub) {
    this.#loader = loader;
    this.#fetchOptions = {};
    this.#subscribeFetchStart();
    this.#subscribeSortingDone();
    this.#subscribeQuickFilterChanged();
    this.#subscribeFilterChange();
    this.#subscribePaginationChange();
    this.#subscribeGroupChange();
  }

  #getData(fetchOptions: DataDenFetchOptions): Promise<any[]> {
    return this.#loader.getData(fetchOptions);
  }

  #publishFetchDone(context: Context, data: any[]): void {
    const EventData: DataDenFetchDoneEvent = {
      caller: this,
      context,
      rows: data,
    };
    this.PubSub.publish('info:fetch:done', EventData);
  }

  #subscribeFetchStart(): void {
    this.PubSub.subscribe('command:fetch:start', (event: DataDenEvent) => {
      this.#getData(this.#fetchOptions).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
      });
    });
  }

  #subscribeSortingDone(): void {
    this.PubSub.subscribe('command:fetch:sort-start', (event: DataDenEvent) => {
      this.#fetchOptions.sortingOptions = {
        field: event.data.field,
        order: event.data.order,
        comparator: event.data.comparator,
        sortFn: event.data.sortFn,
        activeSorters: event.data.activeSorters,
      };
      this.#getData(this.#fetchOptions).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
        DataDenEventEmitter.triggerEvent('sortingDone', this.#fetchOptions.sortingOptions);
      });
    });
  }

  #subscribeQuickFilterChanged(): void {
    this.PubSub.subscribe('info:filtering:active-quick-filter-changed', (event: DataDenEvent) => {
      this.#fetchOptions.quickFilterOptions = {
        searchTerm: event.data.filter.searchTerm,
        columns: event.data.filter.columns,
        filterFn: event.data.filter.filterFn,
      };
      this.#getData(this.#fetchOptions).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
      });
    });
  }

  #subscribeFilterChange(): void {
    this.PubSub.subscribe('info:filtering:active-filters-changed', (event: DataDenEvent) => {
      this.#fetchOptions.filtersOptions = {
        filters: event.data.filters,
      };
      this.#getData(this.#fetchOptions).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
      });
    });
  }

  #subscribePaginationChange(): void {
    this.PubSub.subscribe('info:pagination:info-change:done', (event: DataDenEvent) => {
      this.#fetchOptions.paginationOptions = {
        firstRowIndex: event.data.firstRowIndex,
        lastRowIndex: event.data.lastRowIndex,
      };
      this.#getData(this.#fetchOptions).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
      });
    });
  }

  #subscribeGroupChange(): void {
    this.PubSub.subscribe('command:group:update', (event: DataDenEvent) => {
      this.#fetchOptions.groupedOptions = event.data.groupedColumns.length === 0 ? undefined : {
        groupedColumns: event.data.groupedColumns,
      };

      this.#getData({ groupedOptions: this.#fetchOptions.groupedOptions }).then((data: any[]) => {
        this.#publishFetchDone(event.context, data);
      });
    });
  }
}