Using R to Orchestrate APIs

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# Using R to Orchestrate APIs
## Research Computing Symposium 2017
### John Little
### 2017-02-01

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## Using R to Orchestrate APIs

A presentation for [Research Data at the /Edge](http://library.duke.edu/edge/events/rc17)  
Hosted by the [Data & Visualization Services](http://library.duke.edu/data/) Department  
Day One, [Duke Research Computing Symposium](https://rc.duke.edu/symposium-2017/), 2017

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Image credit: [Moz](https://moz.com/blog/apis-for-datadriven-marketers)

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### Presentation & Supporting Files

- Github Repo -- https://github.com/libjohn/r-api-json

- Web Site -- https://libjohn.github.io/rcs2017/
    - [Slides](https://libjohn.github.com/rcs2017/slides.html)
    - [Demonstration](http://libjohn.github.io/rcs2017/demonstration.nb.html)
    - [Hands-on](http://libjohn.github.io/rcs2017/handson.nb.html)

### Eat Your Own Dogfood

This presentation consists of an R Notebook and slides composed in *Rmarkdown* via *Rstudio*, slides made with `devtools::install_github("yihui/xaringan")`, files stored in a *Github Repository*, Slides & Notebook served via *Github Pages*.

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WARNING:  Mixing Fictions and Metaphors

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## Outline

- API

- JSON

- Orchestration:  Demonstration in RStudio

- Hand's On (*You can use [OIT's RStudio Docker Container](https://vm-manage.oit.duke.edu/containers/rstudio)*)

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## Why APIs?

### The Web has lots of stuff

- frontier beyond curated datasets

- stuff is wrapped in HTML

- HTML is transported over HTTP but composed for h2m consumption

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To get BULK Data!

## Intellectual Property rights bear serious consideration

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Check with the Library's Office of Copyright and Scholarly Communications

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## API

### Application Program Interface

- Built for machine-to-machine interactions

- Instructions for programs

![API schematic](images/api.png)

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### Client / Server

![](images/Client-server-model.svg.png)

- Make [R] interface with the web

- Same as h2m but now m2m

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### h2m Simulation...

- Person enters a URL

![Parts of URL](images/URL.PNG)

--
    
- Client & server negotiate handshake (*dramatization...*)

.right[![dramatization: good handshake](images/good-handshake.gif)]

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- Web Browser parses the HTML

.right[![happy parsing dance](images/result-happyDance.gif)]

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Ever seen HTML before?  
    
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- Information is sent back in wrapped HTML

```html
<!DOCTYPE html>
<html>

 <head>
  <title>sample</title>
 </head>
 <body>
  <p>Voluptatem accusantium
   totam rem aperiam.</p>
 </body>
</html>
```

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## JSON

* [Javascript Object Notation](https://en.wikipedia.org/wiki/JSON) is a language-independent data format
* Currently the most common data data format for asynchronous client/server communication format
* Consists of key-value pairs

```json
# from https://en.wikipedia.org/wiki/JSON
{
  "firstName": "John",
  "lastName": "Smith",
  "isAlive": true,
  "age": 25,
  "address": {
    "streetAddress": "21 2nd Street",
    "city": "New York",
    "state": "NY",
    "postalCode": "10021-3100"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "212 555-1234"
    },
    {
      "type": "office",
      "number": "646 555-4567"
    },
    {
      "type": "mobile",
      "number": "123 456-7890"
    }
  ],
  "children": [],
  "spouse": null
}
```

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## m2m -- development

- Make [R] interface with the web

- Same as h2m but now m2m

*dramatization...*

.right[![dramatization: confused about the protocol](images/development-confusion.gif)]

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## Next

- Demonstration
    - using an API to http://omdb.org (OMDB is like IMDB.com)
    - http://libjohn.github.io/rcs2017
- Hands-on
    - using An API Of Ice And Fire -- http://anapioficeandfire.com/

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## R Packages -- Related

*People who use JSONlite also use...*

* [httR](https://cran.r-project.org/web/packages/httr/) -- calls JSONlite in service to major goal of orchestrating HTTP (web scraping)
* [rvest](https://blog.rstudio.org/2014/11/24/rvest-easy-web-scraping-with-r/) --  used for HTML parsing

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## Resources

- [Extracting Data from the Web Part 1](https://www.rstudio.com/resources/webinars/extracting-data-from-the-web-part-1/). RStudio Webinar Video
- [JSONlite package](https://cran.r-project.org/web/packages/jsonlite/index.html)
- Movies of 1976
    - [OMDB Top Movies](http://www.omdb.org/encyclopedia/year/1976/statistics)
    - [IMDB Most Popular](http://www.imdb.com/year/1976/)
- http://www.omdbapi.com/
- http://anapioficeandfire.com/

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## Image Credits

- [API schematic](https://moz.com/blog/apis-for-datadriven-marketers)
- [Client / Server](https://commons.wikimedia.org/wiki/File:Client-server-model.svg)
- [URL](https://commons.wikimedia.org/wiki/File:Uniform_Resource_Locator_%28URL%29_example.PNG)
- [Good human handshake](http://giphy.com/gifs/thomas-U2XboRuN89Idi)
- [happy parsed dance](http://giphy.com/gifs/80s-1980s-thomas-dolby-wCKmBd7oNtA4g)

- [NASA animated GIF](http://i.giphy.com/l2Jht4lIfEQfJ3zj2.gif)

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## Shareable under CC BY-NC-SA license

Data, presentation, and handouts are shareable under [CC BY-NC-SA license](https://creativecommons.org/licenses/by-nc-sa/4.0/)

![This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.](https://licensebuttons.net/l/by-nc-sa/4.0/88x31.png "This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License")