ngrx

table.reducer.ts

import { TableActions, TableActionTypes } from './table.actions';
import { initialState, State } from './table.state';

export * from './table.state';

export function reducer(state = initialState, action: TableActions): State {
  switch (action.type) {
    case TableActionTypes.LoadMoreTableModels:
      return { ...state, loadedModelsCount: state.loadedModelsCount + action.payload.count };

    case TableActionTypes.ResetTable:
      return { ...initialState, ...action.payload };

    case TableActionTypes.SortColumn:
      return { ...state, ...action.payload };

    case TableActionTypes.UpdateTableModels:
      return { ...state, ...action.payload };

    default:
      return state;
  }
}

export const selectIsFinishedModels = (state: State): boolean => {
  return state.models.length <= state.loadedModelsCount;
};

export const selectSortedModels = (state: State): any[] => {
  if (!state.active || state.direction === '') {
    return state.models;
  }

  const sorted: any[] = Object.assign([], state.models);
  sorted.sort((a, b) => {
    if (a[state.active] > b[state.active]) {
      return -1;
    }
    return 1;
  });

  if (state.direction === 'desc') {
    return sorted.reverse();
  }

  return sorted;
};

export const selectModelsSlice = (state: State): any[] => {
  const sortedModels = selectSortedModels(state);

  return sortedModels.slice(0, state.loadedModelsCount);
};

export const selectTableModelsCount = (state: State): number => state.models.length;