./README.md in sinatra-param-1.4.0 vs ./README.md in sinatra-param-1.5.0

@@ -1,6 +1,7 @@
 # sinatra-param
+
 _Parameter Validation & Type Coercion for Sinatra_
 
 REST conventions take the guesswork out of designing and consuming web APIs. Simply `GET`, `POST`, `PATCH`, or `DELETE` resource endpoints, and you get what you'd expect.
 
 However, when it comes to figuring out what parameters are expected... well, all bets are off.
@@ -25,11 +26,11 @@
 gem "sinatra-param", require: "sinatra/param"
 ```
 
 ## Example
 
-``` ruby
+```ruby
 require 'sinatra/base'
 require 'sinatra/param'
 require 'json'
 
 class App < Sinatra::Base
@@ -45,11 +46,11 @@
   get '/search' do
     param :q,           String, required: true
     param :categories,  Array
     param :sort,        String, default: "title"
     param :order,       String, in: ["ASC", "DESC"], transform: :upcase, default: "ASC"
-    param :price,       String, format: "[<\=>]\s*\$\d+"
+    param :price,       String, format: /[<\=>]\s*\$\d+/
 
     one_of :q, :categories
 
     {...}.to_json
   end
@@ -58,32 +59,44 @@
 
 ### Parameter Types
 
 By declaring parameter types, incoming parameters will automatically be transformed into an object of that type. For instance, if a param is `Boolean`, values of `'1'`, `'true'`, `'t'`, `'yes'`, and `'y'` will be automatically transformed into `true`.
 
-- `String`
-- `Integer`
-- `Float`
-- `Boolean` _("1/0", "true/false", "t/f", "yes/no", "y/n")_
-- `Array` _("1,2,3,4,5")_
-- `Hash` _(key1:value1,key2:value2)_
-- `Date`, `Time`, & `DateTime`
+* `String`
+* `Integer`
+* `Float`
+* `Boolean` _("1/0", "true/false", "t/f", "yes/no", "y/n")_
+* `Array` _("1,2,3,4,5")_
+* `Hash` _(key1:value1,key2:value2)_
+* `Date`, `Time`, & `DateTime`
 
 ### Validations
 
 Encapsulate business logic in a consistent way with validations. If a parameter does not satisfy a particular condition, a `400` error is returned with a message explaining the failure.
 
-- `required`
-- `blank`
-- `is`
-- `in`, `within`, `range`
-- `min` / `max`
-- `format`
+* `required`
+* `blank`
+* `is`
+* `in`, `within`, `range`
+* `min` / `max`
+* `min_length` / `max_length`
+* `format`
 
+### Custom Error Messages
+
+Passing a `message` option allows you to customize the message
+for any validation error that occurs.
+
+```ruby
+param :spelling,
+      format: /\b(?![a-z]*cie)[a-z]*(?:cei|ie)[a-z]*/i,
+      message: "'i' before 'e', except after 'c'"
+```
+
 ### Defaults and Transformations
 
-Passing a `default` option will provide a default value for a parameter if none is passed.  A `default` can defined as either a default or as a `Proc`:
+Passing a `default` option will provide a default value for a parameter if none is passed. A `default` can defined as either a default or as a `Proc`:
 
 ```ruby
 param :attribution, String, default: "©"
 param :year, Integer, default: lambda { Time.now.year }
 ```
@@ -122,24 +135,24 @@
 
 By default, when a parameter precondition fails, `Sinatra::Param` will `halt 400` with an error message:
 
 ```json
 {
-    "message": "Invalid parameter, order",
-    "errors": {
-        "order": "Param must be within [\"ASC\", \"DESC\"]"
-    }
+  "message": "Parameter must be within [\"ASC\", \"DESC\"]",
+  "errors": {
+    "order": "Parameter must be within [\"ASC\", \"DESC\"]"
+  }
 }
 ```
 
 To change this, you can set `:raise_sinatra_param_exceptions` to `true`, and intercept `Sinatra::Param::InvalidParameterError` with a Sinatra `error do...end` block. (To make this work in development, set `:show_exceptions` to `false` and `:raise_errors` to `true`):
 
 ```ruby
 set :raise_sinatra_param_exceptions, true
 
 error Sinatra::Param::InvalidParameterError do
-    {error: "#{env['sinatra.error'].param} is invalid"}.to_json
+    { error: "#{env['sinatra.error'].param} is invalid" }.to_json
 end
 ```
 
 Custom exception handling can also be enabled on an individual parameter basis, by passing the `raise` option:
 
@@ -149,10 +162,10 @@
 one_of :q, :categories, raise: true
 ```
 
 ## Contact
 
-Mattt Thompson ([@mattt](http://twitter.com/mattt))
+Mattt ([@mattt](http://twitter.com/mattt))
 
 ## License
 
 sinatra-param is released under an MIT license. See LICENSE for more information.