ng2-resource-rest troubleshoot

course-calendar.component.ts

import { Component,
         OnInit,
         OnDestroy } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { SessionResource } from '../../shared/resources/';
import { Subscription } from 'rxjs';

@Component({
  selector: 'app-course-calendar',
  template: `
    ...
  `,
  providers: [SessionResource]
})
export class CourseCalendarComponent implements OnInit, OnDestroy {

  items: any;

  private sub: Subscription;

  constructor(
    private resource: SessionResource,
    private route: ActivatedRoute
  ) { }

  ngOnInit() {
    this.sub = this.route
      .params
      .subscribe(params => {
        this.items = this.resource.query({ courseID: params['id'] });
      });
  }

  ngOnDestroy() {
    this.sub.unsubscribe();
  }

}

sequence-calendar.component.ts

import { Component,
         OnInit,
         OnDestroy } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { SessionResource } from '../../shared/resources/';
import { Subscription } from 'rxjs';

@Component({
  selector: 'app-sequence-calendar',
  template: `
    ...
  `,
  providers: [SessionResource]
})
export class SequenceCalendarComponent implements OnInit, OnDestroy {

  items: any;

  private sub: Subscription;

  constructor(
    private resource: SessionResource,
    private route: ActivatedRoute
  ) { }

  ngOnInit() {
    this.sub = this.route
      .params
      .subscribe(params => {
        this.items = this.resource.query({ seqID: params['id'] });
      });
  }

  ngOnDestroy() {
    this.sub.unsubscribe();
  }
}

session.resource.ts

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { Resource,
         ResourceParams } from 'ng2-resource-rest';

function resourceParamsWithPathType(pathType: string) {
  return {
    url: (
        REDACTED_API_URL + pathType + '/{id}',
    removeTrailingSlash: false,
    data: {
      acadYear: 2017
    }
  };
}

@Injectable()
@ResourceParams(resourceParamsWithPathType('session'))
export class SessionResource extends Resource {

  constructor(protected http: Http) {
    super(http);
  }

  query(data?, callback?) {
    return super.query(data, function(result) {
      result = result.sort(function(a, b) {
        return Date.parse(a.start) - Date.parse(b.start);
      });

      if (callback) {
        callback(result);
      }
    });
  }

}