ionic-tryton-infinite-list/infinite-list.ts

import { Component } from '@angular/core';
import { NavController, Events } from 'ionic-angular';

import { TrytonProvider } from '../ngx-tryton-providers/tryton-provider'

import { EncodeJSONRead } from '../ngx-tryton-json/encode-json-read'

@Component({
  selector: 'infnite-list',
  templateUrl: 'infinite-list-example.html',
})
/**
 * Locations page.
 * This view exposes a infinite scrolling list.
 * An infinite scrolling list is a list that its not loaded will all the date
 * but it keeps updating itself with new date once the user scrolls pass
 * a thereshold.
 *
 * DO NOT MODIFY THIS CLASS, EXTEND IT INSTEAD
 */
export class InfiniteList {
  /**
   * Method to search information
   * @type {string}
   */
  method: string;
  /**
   * Domain of the method
   * @type {array}
   */
  domain: any[];
  /**
   * Fields to search
   * @type {Array<string>}
   */
  fields: Array<string>;
  /**
   * Default location value
   * @type {string}
   */
  default_value: string;
  /**
   * Current offset, this number will increase each time more data is loaded
   * @type {number}
   */
  offset: number = 0;
  /**
   * Number of entries to gather from the server
   * @type {number}
   */
  limit: number = 10;
  /**
   * Limit to search
   * @type {Array<any>}
   */
  order: Array<any> = [];
  /**
   * Items to display
   * @type {Array<any>}
   */
  list_items: Array<any> = [];


  constructor(public navCtrl: NavController,
    public trytond_provider: TrytonProvider,
    public events: Events) {
  }

  errorHandler(error: any): void {
     let httpErrorCode = error['status'];
     switch (httpErrorCode) {
       case 301:
         alert(error);
         console.log(error);
         // alert('Session expired. Try to relogin');
         break;
       case 401:
         alert(error);
         console.log(error);
         // alert('Session expired. Try to relogin');
         break;
       default:
       console.log(error);
     }
  }

  /**
   * Allows a view to have infinite scrolling, meaning that it will not
   * load all the items from a list at the same time, but will load them as
   * time goes on.
   * @param {any} infiniteScroll Infinite scroll event
   */
  doInfinite(infiniteScroll: any) {
    if (this.list_items.length == 0)
      infiniteScroll.enable(false);
      this.loadData().then(() => {
        infiniteScroll.complete();
      })
  }

  /**
   * Loads new data into the data array
   */
  loadData() {
    let json_constructor = new EncodeJSONRead;
    json_constructor.addNode(this.method, this.domain, this.fields, this.offset, this.limit, this.order || []);

    let json = json_constructor.createJson()

    return new Promise(resolve => {
      this.trytond_provider.search(json).subscribe(
      data =>{
        // We do this so we can be sure of the data type afterwards
        this.list_items = this.list_items.concat(data[this.method]);
        this.offset += this.limit;
        this.events.publish("Data loading finished");
        resolve(true);
      },
      error => {
          // console.log("Error", error);
          this.errorHandler(error);
      });
    })
  }
}