Expositus
Author: Mark Fischer, Jr.
Posted: May 17, 2015
Tags: programming, web

Using REST Inside Programs

Rich Hickey proposed an interesting idea in his keynote at RailsConf 2012. The idea, if I understand correctly, is that if serialization is good between servers as a way to separate concerns, then why don’t we do it between different sections of code on the same server?

Using REST between different code blocks seems like a good idea, but serialization seems a bit useless in my humble opinion, since it only seems to add complexity to the program.

I decided to write a little proof-of-concept for this program in Python. There is a module rest.py which currently contains one class: CRUD. CRUD has four built-in functions: create(), read(), update(), and delete().

Here is the documentation for each of the built-in functions:

create(object)
"""
Creates a new object.

Keyword arguments:
object -- Object or list of objects to create
"""

read()
"""Returns a list of created objects."""

update(objectId, object)
"""
Updates object.

Keyword arguments:
objectId -- Key of object to update
object -- Object to update with
"""

delete(objectId)
"""
Deletes object from list.

Keyword arguments:
objectId -- Key of object to delete
"""

The built-in commands operate on an internal list _objects, accessible through read(). Here is a simple example using the default methods.

from rest import CRUD

# A dictionary entry class
class DictEntry:
    Word = ""
    Definition = ""

    def __init__(self, word, definition):
        self.Word = word
        self.Definition = definition

    def __repr__(self):
        return "(Word: {0}, Definition: {1})".format(self.Word, self.Definition)

# Make a CRUD instance
Dictionary = CRUD()

# Add a word to our dictionary
Dictionary.create(DictEntry("Programmer", "A being that converts pizza and Coke into crde"))

# Update the word
Dictionary.Update(0, DictEntry("Programmer", "A being that converts pizza and Coke into code")

# Print the dictionary out to the terminal
print(Dictionary.read())

# Delete the word
Dictionary.Delete(0)

# Print the (empty) dictionary out to the terminal
print(Dictionary.read())

Not sure how useful this is going to be, but it was fun to code up!

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