Welcome to the Code Maven!
While the two words crawling and scraping are usually interchangeable - at least when we are talking about the web - they still might have sime slightly different meaning. Crawling usually refers to the acto of going from page to page, traversing one or more sites. Scraping on the other hand usually refers to analyzing one or a very limited set of pages.
Or maybe I am just making up this distinction. Who knows what other means by these words?
Even though we are calling this applications "Single Page Applications", because we let the browser talk to the server behind the scenes, in the end in many application we'll have multiple "views". For example Gmail has the "list inbox" view and the "show single email" view and probably a few other views.
In the big counter example mostly we use programming languages, but this time I am going to use the MongoDB client to implement a counter. Later we can use this example to build counters using some programming language and MongoDB as the storage facility.
Ruby has two operators to generate a range of values. .. is inclusive and ... is exclusive.
Here you'll find a few simple examples using AngularJS, slowly building up to become a Tutorial.
For other introductions you might want to look at the AngularJS Book by Chris Smith or the ng-book by Ari Lerner. Once you get over the first steps, reading the AngularJS API and documentation becomes quite useful.
There are tons of web sites with public API that we could access, but most of them use the default CORS security setting (by not setting Access-Control-Allow-Origin) which means we can only access their API from the command line or from the server and not from the browser.
On this page you'll find a collection of web sites that provide public APIs with Access-Control-Allow-Origin enabled. You can access them to fetch data via Ajax requests.
Trailing closely the Hello world, the Echo, and the simple calculator examples, creating a TODO list is one of the rite of passage entering the world of whatever language or environment. Let's see how to implement a TODO using AngularJS.