JavaScript

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Fake news (multipage, library)

The story so far

You have a BS template with some JS to load a navbar, and footer. You know how to make input fields, and buttons. You know how to tie JS code to events. You know how to validate. You know how to use variables to coordinate what happens across events. You know how to persist data, and erase persisted data when needed.

This lesson adds a few new things:

  • An app with multiple pages.
  • Generating HTML with JavaScript.
  • Adding a library of utility functions copied from the web

Requirements

Goals

Our app will make a fake news feed.

Security

The story so far

Groovy! We have all of the CRUD. We are the CRUDiest. CRUDtastic.

One thing left: security. More specifically, we'll talk about authorization, or user permissions. This is one part of security, but an important part.

Earlier, you learned how to add Edit and Delete buttons to every record. Trouble is, that lets anyone delete your data. They go to the right URL, and keep clicking the Delete button.

Remember, normally DBs are kept on servers, so if one persons deletes data, it's gone for everyone.

Let's add some authorization.

h2.

Ships

The story so far

This course is about making CRUD apps. You know how to do C(reate), and R(ead), and all the appy goodness behind them. Now let's add D(elete). We'll also firm up the way we connect pages.

This lesson is longer than most. Much of it is review. You've already seen how to work with TaffyDB, list data, and add new records. This lesson explains that again, as one last check. Go through the code. You should be able to follow it without much trouble. It will give you confidence that you know what's going on.

Plan to take a break part-way through the lesson.

Dog pack

The story so far

Persisting record sets

There's a problem with the course data app in the previous lesson. It doesn't remember anything. We created a record set when the page loads:

(function($) {
    //Initialize course catalog.
    var catalog = [
        {
            id: 42,
            title: "Web apps for happy dogs",
            maxEnrollment: 40,
            location: "Monty Hall 301"
        },
        ...
    ];

It was lost when the page ended.

We want something like this:

bc.

Course catalog: one course

CRUD web apps deal with structured data, like rows in database tables. We'll be using JS objects for that.

An object is a collection of data and functions. You've already been making objects, without knowing it. You know those namespacing things?

<script>
"use strict";
var CourseScore = CourseScore || {};

CourseScore is a JS object.

JSON

Suppose we want a catalog of university courses. Let's start with one course for now. Here's how you could store information about it:

bc.