Intro to API's

Connecting with other applications

API

Application Programming Interface

"FB, Talk to me!"

API's are interfaces for code/computers to talk to one another.

Web API's

Generally communicate via HTTP

• Twitter API, give me all tweets that mention "ice cream"
• Facebook API, send me the current user's profile picture
• Weather API, what is the weather in Missoula Montana?
• Reddit API, what is the current top post?
• GooglePlaces API, what gas stations are near the user?
• Yelp API, give me 10 restaurants in the zipcode 94110

A Human Interface

The itunes API

Make an HTTP request to:  

https://itunes.apple.com/search?term=beyonce&entity=musicVideo

https://itunes.apple.com/search?term=beyonce&entity=album

https://itunes.apple.com/search?term=beatles&entity=song

https://itunes.apple.com/search?term=code&entity=podcast

https://itunes.apple.com/search?term=harry-potter&entity=movie

Make an HTTP request to an API

Get Some Data Back!

Search for Beyonce Albums

Search for Beatles Songs

Search for Podcasts About "code"

Search for Harry Potter Movies

Data Formats

When we use the internet, we make HTTP request and get HTML back.

API's don't respond with HTML.  HTML contains information about the structure of a page.  API's respond with data, not structure.

They use simpler data formats like XML and JSON

XML

Extended Markup Language

XML is syntacticly similar to HTML, but it does not describe presentation like HTML does

<person>
    <age>21</age>
    <name>Travis</name>
    <city>Los Angeles</city>
</person>

JSON

Javascript Object Notation

JSON looks exactly like JavaScript objects, but everything is a string

{
 "person": {
   "age": "21",
   "name": "Travis",
   "city": "Los Angeles"
 }
}

XML vs. JSON

{
 "person": {
   "age": "21",
   "name": "Travis",
   "city": "Los Angeles"
 }
}

<person>
    <age>21</age>
    <name>Travis</name>
    <city>Los Angeles</city>
</person>

XML vs. JSON

{
 "person": {
   "age": "21",
   "name": "Travis",
   "city": "Los Angeles"
 }
}

<person>
    <age>21</age>
    <name>Travis</name>
    <city>Los Angeles</city>
</person>