README.md in lou-0.0.1 vs README.md in lou-0.1.0
- old
+ new
@@ -2,11 +2,11 @@
===
[](https://travis-ci.org/iainbeeston/lou)
[](https://codeclimate.com/github/iainbeeston/lou)
-Lou lets you define a pipeline of reversible transformations, that you can apply to any ruby object. For example, you might want to define a pipeline of [ImageMagick](http://www.imagemagick.org) operations on an image, or a sequence of API calls.
+Lou lets you define a pipeline of reversible transformations, that you can apply to any ruby object. It assumes nothing about your business logic or the objects that you're using. For example, you might want to define a pipeline of [ImageMagick](http://www.imagemagick.org) operations on an image, or a sequence of API calls. You could even use Lou as a replacement for ActiveRecord migrations.
Usage
-----
You can define transformations in their own class like this:
@@ -15,34 +15,36 @@
require 'lou'
class HashTransformer
extend Lou
- transform forward do |x|
+ transform.up do |x|
x.merge(a_new_key: 'this is new')
- end.backward do |x|
+ end.down do |x|
x.delete(:a_new_key)
x
end
- transform forward do |x|
+ transform.up do |x|
x.flatten
- end.backward do |x|
+ end.down do |x|
Hash[*x]
end
end
~~~
Then you can use it like this:
~~~ruby
result = HashTransformer.apply(an_old_key: 'this is old')
# [:an_old_key, "this is old", :a_new_key, "this is new"]
-original = HashTransformer.undo(result)
+original = HashTransformer.reverse(result)
# {:an_old_key=>"this is old"}
~~~
-The transforms are applied in the order that they're defined using the ~apply~ function, with each transform receiving the result of the previous one. The process can be reversed using the ~undo~ function.
+The transforms are applied in the order that they're defined using the ~apply~ function, with each transform receiving the result of the previous one. The process can be reversed using the ~reverse~ function.
+
+Note that for each transform, the input is the result of the previous step.
Credits
-------
Lou is heavily inspired by [Hash Mapper](http://github.com/ismasan) by [Ismael Celis](http://github.com/ismasan).
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