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Two things
I found effective
when starting up
a new web service
Tech Talk Tokyo #2
May 24th, 2016.
@necojackarc
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Taka
Software Engineer
Twitter: @necojackarc
GitHub: necojackarc
Blog (JP): http://necojackarc.hatenablog.com/
Blog (EN): http://necojackarc.hateblo.jp/
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Outline
○ Introducing a new web service by PIXTA
○ Sharing two effective methods which
make systems more extensible:
● Immutable Data Model with additional restrictions
● Adding extra components to MVC frameworks,
especially “Ruby on Rails”
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1.
Introducing
a new web service
The name is “fotowa”.
URL: https://fotowa.com/
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About “fotowa”
III. photo shoot & online delivery
II. request
IV. reward
I. registration
Matching service between those who want to
have their photos taken and photographers
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Development of “fotowa”
○ We released the first version on February
29th, 2016.
○ It took one and a half months.
○ I needed to take care of a lot of changes
because the requirements weren't fixed.
○ I found some methods which were
effective to deal with frequent changes.
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2.
Extended
Immutable Data
Model
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What is Immutable Data Model?
○ One of the styles of data modeling
○ In a word, forbidding updating database
● Practically, it’s almost impossible to make an
application without updating any data.
● So, it’s okay to just try and exclude as much
update as possible.
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Benefits of Immutable Data
Model
○ Keeping your data model simple
● Updating usually causes complexity.
○ Making your design open to change
● You can easily extend and modify the design.
○ Making your database robust
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Let’s apply
additional
restrictions!
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Additional restrictions
They improve your database much more!
○ Never updating records (already adopted)
○ Never deleting records
○ No null columns
○ No deleted flags
The more restrictions you apply, the more
improvements you (might be able to) get :)
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3.
Adding extra
components to
Rails
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Brief introduction of Ruby on
Rails
○ It’s a MVC framework.
● It originally has three components that are
models, controllers and views.
○ Developers often suffer from “fat stuff”.
● Since Rails has only three components,
developers tend to put “all business logic” on
controllers or models. It causes fat models or fat
controllers.
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“
You may be thinking:
“But Rails makes it really hard to
do OOP right!”
from “7 Patterns to Refactor Fat ActiveRecord Models”
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It’s not true.
Adding extras
solves these
problems.
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● Decorators
● Errors
● Forms
● Lib
● Observers
● Parameters
● Serializers
● Services
● Uploaders
Components I actually added
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It enables you
to apply Single
Responsibility
Principle.
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Conclusion
○ Extended Immutable Data Model makes
your database open to change.
○ Adding extra components enables you to
follow Single Responsibility Principle which
makes your application open to change.
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Changes are
inevitable
Let’s prepare for changes!
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References
○ イミュータブルデータモデル(入門編)
● http://www.slideshare.net/kawasima/ss-40471672
○ SIerにおけるDBAのしごと
● http://qiita.com/kawasima/items/7eafd8406866f9d6e91b
○ 7 Patterns to Refactor Fat ActiveRecord Models
● http://blog.codeclimate.com/blog/2012/10/17/7-ways-to-decomp
ose-fat-activerecord-models/
○ 肥大化したActiveRecordモデルをリファクタリングする7つの方法(翻訳)
● http://techracho.bpsinc.jp/hachi8833/2013_11_19/14738
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THANKS!