diff --git a/.gitignore b/.gitignore
index e3857c4..f3db545 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,3 +35,4 @@ atlassian-ide-plugin.xml
 com_crashlytics_export_strings.xml
 
 Gemfile.lock
+*.gem
diff --git a/README.md b/README.md
index 0f229bd..960d2d3 100644
--- a/README.md
+++ b/README.md
@@ -4,30 +4,113 @@
 
 ## Background
 
-JSON Content Rules (JCR) is a JSON-specific schema language. JCR was created by ARIN in an effort
-to better describe JSON structures in RDAP.
+JSON Content Rules (JCR) is a language for specifying and testing the interchange of data in JSON format used by computer protocols and processes.  The syntax of JCR is not JSON but is "JSON-like", possessing the conciseness and utility that has made JSON popular. It was created by the American Registry for Internet Numbers (ARIN) in an effort to better describe the JSON structures in protocols such as RDAP.
 
-At present, this software is ahead of the specification.
-The current version of the JCR specification can be found here:
-http://tools.ietf.org/html/draft-newton-json-content-rules-05
+### A First Example: Specifying Content
 
-## Usage
+   The following JSON data describes a JSON object with two members,
+   "line-count" and "word-count", each containing an integer.
 
-Use bundler to install all the dependencies.
+      { "line-count" : 3426, "word-count" : 27886 }
 
-If you do not have bundler, it is simple to install:
+   This is also JCR that describes a JSON object with a member named
+   "line-count" that is an integer that is exactly 3426 and a member
+   named "word-count" that is an integer that is exactly 27886.
 
-```
-$ gem install bundler
-```
+   For a protocol specification, it is probably more useful to specify
+   that each member is any integer and not specific, exact integers:
+
+      { "line-count" : integer, "word-count" : integer }
+
+   Since line counts and word counts should be either zero or a positive
+   integer, the specification may be further narrowed:
+
+      { "line-count" : 0.. , "word-count" : 0.. }
+      
+### A Second Example: Testing Content
+
+   Building on the first example, this second example describes the same
+   object but with the addition of another member, "file-name".
+
+      {
+        "file-name"  : "rfc7159.txt",
+        "line-count" : 3426,
+        "word-count" : 27886
+      }
+
+   The following JCR describes objects like it.
+
+      {
+        "file-name"  : string,
+        "line-count" : 0..,
+        "word-count" : 0..
+      }
 
-From there, tell bundler to go get the rest of the gems:
+
+   For the purposes of writing a protocol specification, JCR may be
+   broken down into named rules to reduce complexity and to enable re-use.  The following example takes the JCR from above and rewrites the
+   members as named rules.
+
+      {
+        fn,
+        lc,
+        wc
+      }
+
+      fn "file-name"  : string
+      lc "line-count" : 0..
+      wc "word-count" : 0..
+
+   With each member specified as a named rule, software testers can
+   override them locally for specific test cases.  In the following
+   example, the named rules are locally overridden for the test case
+   where the file name is "rfc4627.txt".
+
+      fn "file-name"  : "rfc4627.txt"
+      lc "line-count" : 2102
+      wc "word-count" : 16714
+
+   In this example, the protocol specification describes the JSON object
+   in general and an implementation overrides the rules for testing
+   specific cases.
+   
+### More Information on JCR
+
+More information on JCR can be found at [json-content-rules.org](http://json-content-rules.org/). The current specification is an IETF Internet Draft (I-D) versioned as -05. It can be found [here](http://tools.ietf.org/html/draft-newton-json-content-rules-05).
+   
+## Version History
+
+* 0.5.0 - First test GEM push.
+* 0.5.1 - First public beta.
+  * Small fix to bin/jcr to capture exit codes properly
+  * Small enhancement to bin/jcr to suck in multiple JSON files
+  * At present, this software is ahead of the specification.
+The current version of the JCR specification can be found 
+[here](http://tools.ietf.org/html/draft-newton-json-content-rules-05)
+  
+## Features
+
+This JCR Validator can be used by other Ruby code directly, or it may be invoked on the command line using the `jcr` command.
+
+The command line utility can be given specific rulesets to override a primary testing for the purposes of local testing. If no root rule is given, it will test against all roots.
+
+The library has all the features of the command line utility, and also has the ability to allow for custom validation of rules using Ruby code.
+  
+## Installation
+
+To install the JCR Validator:
 
 ```
-$ bundle install
+gem install jcrvalidator
 ```
 
-Now you can validate JSON against JCR.
+This code was written and tested on Ruby 2.0. 
+
+## Command Line Usage
+
+You can find a bunch of command line examples in `examples/examples.sh`
+
+Here are some quick nibbles:
 
 ```
 $ echo "[ 1, 2]" | bin/jcr -v -R "[ *:integer ]"
@@ -43,22 +126,61 @@ $ bin/jcr -h
 HELP
 ----
 
-Usage: jcr [OPTIONS] [JSON_FILE]
+Usage: jcr [OPTIONS] [JSON_FILES]
 
 Evaluates JSON against JSON Content Rules (JCR).
 
-If JSON_FILE is not specified, standard input (STDIN) is used.
+If JSON_FILES is not specified, standard input (STDIN) is used.
 
 Use -v to see results, otherwise check the exit code.
 
 Options
     -r FILE                          file containing ruleset
     -R STRING                        string containing ruleset. Should probably be quoted
+    -s STRING                        name of root rule. All roots will be tried if none is specified
     -o FILE                          file containing overide ruleset (option can be repeated)
+    -O STRING                        string containing overide rule (option can be repeated)
     -v                               verbose
     -h                               display help
 ```
 
-This code was written and tested on Ruby 2.0. At present it can only run its unit
-tests. Feel free to fiddle with it. To run the unit tests, simply run the `rspec` command.
+## Usage as a Library
+
+It is easy to call the JCR Validator from Ruby programs. The `examples` directory contains some good examples:
+
+* `simple.rb` is a simple and basic example
+* `override.rb` shows how to override specific rules in a ruleset.
+* `callback.rb` demonstrates how to do custom validation with callbacks
+
+### Custom Validation Using Callbacks
+
+The `callback.rb` demonstrates the usage of custom code for evaluation of rules. There are a few important things to note about how callbacks work:
+
+1. The validator will first evaluate a rule with internal validation before calling the callback code. This means child rules are evaluated by the validators own internal logic before a callback is invoked, and also that a callback for a child rule is called before the callback for its parent.
+2. Depending on the internal evaluation, the callback is either invoked at the `rule_eval_true` or `rule_eval_false` methods.
+3. The callback can return a `JCR::Evaluation` object to signify if the evaluation passed or not.
+4. If the callback simply returns true, this is turned into a `JCR::Evaluation` signifying a passed evaluation.
+5. If the callback returns false or a string, this is turned into a `JCR::Evaluation` signifying a failed evaluation. In cases where a string is returned, the string is used as the reason for failing the evaluation.
+6. For validation of rules inside arrays and objects, a failed evaluation will usually result in the terminating the evaluation of the rest of the sibling rules of the containing array or object.
+
+## Building
+
+Use bundler to install all the dependencies.
+
+If you do not have bundler, it is simple to install:
 
+```
+$ gem install bundler
+```
+
+From there, tell bundler to go get the rest of the gems:
+
+```
+$ bundle install
+```
+
+To run the unit tests:
+
+```
+rspec
+````
diff --git a/bin/jcr b/bin/jcr
index 39e559d..5568f26 100755
--- a/bin/jcr
+++ b/bin/jcr
@@ -22,5 +22,5 @@ rescue LoadError
   require 'jcr'
 end
 
-JCR.main
+exit JCR.main
 
diff --git a/example_override.jcr b/example_override.jcr
deleted file mode 100644
index 07cb17a..0000000
--- a/example_override.jcr
+++ /dev/null
@@ -1,2 +0,0 @@
-my_integers : 0..1
-
diff --git a/examples/callback.rb b/examples/callback.rb
new file mode 100644
index 0000000..455d422
--- /dev/null
+++ b/examples/callback.rb
@@ -0,0 +1,75 @@
+# Copyright (C) 2016 American Registry for Internet Numbers (ARIN)
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+# IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# This example demonstrates using the JCR Validator with callbacks
+# to perform custom validation
+
+require 'jcr'
+
+ruleset = <<RULESET
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+
+; this will be the rule we custom validate
+my_integers :0..4
+
+my_strings ( :"foo" | :"bar" )
+
+RULESET
+
+# Create a JCR context.
+ctx = JCR::Context.new( ruleset )
+
+# A local variable used in the callback closure
+my_eval_count = 0
+
+# The callback is created using a Proc object
+c = Proc.new do |on|
+  is_even = false
+
+  # called if the rule evaluates to true
+  # jcr is the rule
+  # data is the data being evaluated against the rule
+  on.rule_eval_true do |jcr,data|
+    my_eval_count = my_eval_count + 1
+    is_even = data.to_i % 2 == 0
+  end
+
+  # called if the rule evaluates to false
+  # jcr is the rule
+  # data is the data being evaluated against the rule
+  # e is the evaluation of the rule
+  on.rule_eval_false do |jcr,data,e|
+    my_eval_count = my_eval_count + 1
+    is_even = data.to_i % 2 == 0
+  end
+
+  # return the custom validation
+  is_even
+end
+
+# register the callback to be called for the "my_integers" rule
+ctx.callbacks[ "my_integers" ] = c
+
+data1 = JSON.parse( '[ 2, 4, "foo", "bar" ]')
+e = ctx.evaluate( data1 )
+puts "Ruleset evaluation of JSON = " + e.success.to_s
+puts "my_eval_count = " + my_eval_count.to_s
+
+data2 = JSON.parse( '[ 3, 4, "foo", "bar" ]')
+e = ctx.evaluate( data2 )
+puts "Ruleset evaluation of JSON = " + e.success.to_s
+puts "my_eval_count = " + my_eval_count.to_s
diff --git a/example.jcr b/examples/example1.jcr
similarity index 100%
rename from example.jcr
rename to examples/example1.jcr
diff --git a/examples/example1_override.jcr b/examples/example1_override.jcr
new file mode 100644
index 0000000..befe66f
--- /dev/null
+++ b/examples/example1_override.jcr
@@ -0,0 +1,2 @@
+my_integers : 0..2
+
diff --git a/example.json b/examples/example1a.json
similarity index 100%
rename from example.json
rename to examples/example1a.json
diff --git a/examples/example1b.json b/examples/example1b.json
new file mode 100644
index 0000000..b753e74
--- /dev/null
+++ b/examples/example1b.json
@@ -0,0 +1,4 @@
+[
+  3, 4,
+  "bar", "foo"
+]
\ No newline at end of file
diff --git a/example2.jcr b/examples/example2.jcr
similarity index 100%
rename from example2.jcr
rename to examples/example2.jcr
diff --git a/examples/examples.sh b/examples/examples.sh
new file mode 100755
index 0000000..e64cf8d
--- /dev/null
+++ b/examples/examples.sh
@@ -0,0 +1,93 @@
+#@IgnoreInspection BashAddShebang
+# Copyright (C) 2015 American Registry for Internet Numbers (ARIN)
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+# IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+# Pass JSON into the JCR validator against a ruleset given on the command line
+# This one should succeed
+echo
+echo "[ 1, 2]" | jcr -v -R "[ *:integer ]"
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Pass JSON into the JCR validator against a ruleset given on the command line
+# This one should fail
+echo
+echo "[ 1, 2]" | jcr -v -R "[ *:string ]"
+if [ $? != 1 ]; then
+  echo "** Unexpected return value"
+else
+  echo "Failed to validate - this is expected"
+fi
+
+# Pass JSON into the JCR validator from a file with a ruleset specified in a file
+# This one should succeed
+echo
+jcr -v -r example1.jcr example1a.json
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Pass JSON into the JCR validator from a file with a ruleset specified in a file
+# This one should succeed
+echo
+jcr -v -r example1.jcr example1b.json
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Pass multiple JSON files into the JCR validator using a ruleset specified in a file
+echo
+jcr -v -r example1.jcr example1*.json
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Override a rule from the command line
+# Should succeed
+echo
+jcr -v -r example1.jcr -O "my_integers :0..2" example1a.json
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Override a rule from the command line
+# Should fail
+echo
+jcr -v -r example1.jcr -O "my_integers :0..2" example1b.json
+if [ $? != 1 ]; then
+  echo "** Unexpected return value"
+else
+  echo "Failed to validate - this is expected"
+fi
+
+# Override a rule from a file
+# Should succeed
+echo
+jcr -v -r example1.jcr -o example1_override.jcr example1a.json
+if [ $? != 0 ]; then
+  echo "** Unexpected return value"
+fi
+
+# Override a rule from a file
+# Should fail
+echo
+jcr -v -r example1.jcr -o example1_override.jcr example1b.json
+if [ $? != 1 ]; then
+  echo "** Unexpected return value"
+else
+  echo "Failed to validate - this is expected"
+fi
+
diff --git a/examples/override.rb b/examples/override.rb
new file mode 100644
index 0000000..5ccbbac
--- /dev/null
+++ b/examples/override.rb
@@ -0,0 +1,54 @@
+# Copyright (C) 2015 American Registry for Internet Numbers (ARIN)
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+# IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# This example demonstrates overriding rules in a ruleset with a secondary ruleset
+
+require 'jcr'
+
+ruleset = <<RULESET
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+RULESET
+
+override = <<OVERRIDE
+my_integers :0..1
+OVERRIDE
+
+# Create a JCR context.
+ctx = JCR::Context.new( ruleset )
+
+# Evaluate the JSON without the override
+data = JSON.parse( '[ 1, 2, "foo", "bar" ]')
+e = ctx.evaluate( data )
+# Should be true
+puts "Ruleset evaluation of JSON = " + e.success.to_s
+
+# Create a new context with overriden rules
+new_ctx = ctx.override( override )
+e = new_ctx.evaluate( data )
+# Should be false
+puts "New Context Ruleset evaluation of JSON = " + e.success.to_s
+
+# The first context can be modified as well
+ctx.override!( override )
+e = ctx.evaluate( data )
+# Should be false
+puts "Overriden Ruleset evaluation of JSON = " + e.success.to_s
+
+
diff --git a/examples/simple.rb b/examples/simple.rb
new file mode 100644
index 0000000..f07e83d
--- /dev/null
+++ b/examples/simple.rb
@@ -0,0 +1,44 @@
+# Copyright (C) 2015 American Registry for Internet Numbers (ARIN)
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+# IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# This example demonstrates using the JCR Validator with a ruleset to
+# evaluate two different sets of JSON data
+
+require 'jcr'
+
+ruleset = <<RULESET
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+RULESET
+
+# Create a JCR context.
+# This is done for effeciency sake when evaluating multiple JSON
+ctx = JCR::Context.new( ruleset )
+
+# Evaluate the first JSON
+data1 = JSON.parse( '[ 1, 2, "foo", "bar" ]')
+e = ctx.evaluate( data1 )
+# Should be true
+puts "Ruleset evaluation of JSON = " + e.success.to_s
+
+data2 = JSON.parse( '[ 2, 1, "bar", "foo" ]')
+e = ctx.evaluate( data2 )
+# Should be true
+puts "Ruleset evaluation of JSON = " + e.success.to_s
+
diff --git a/jcrvalidator.gemspec b/jcrvalidator.gemspec
new file mode 100644
index 0000000..be2755f
--- /dev/null
+++ b/jcrvalidator.gemspec
@@ -0,0 +1,17 @@
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+
+Gem::Specification.new do |s|
+  s.name        = 'jcrvalidator'
+  s.version     = '0.5.1'
+  s.date        = '2015-12-31'
+  s.summary     = "JCR Validator"
+  s.description = "A JSON Content Rules (JCR) Validator library and command line utility."
+  s.authors     = ["Andrew Newton","Pete Cordell"]
+  s.email       = 'andy@arin.net'
+  s.files       = Dir["lib/**/*"].entries
+  s.homepage    =
+          'https://github.com/arineng/jcrvalidator'
+  s.license       = 'ISC'
+  s.executables << 'jcr'
+end
\ No newline at end of file
diff --git a/lib/jcr/evaluate_array_rules.rb b/lib/jcr/evaluate_array_rules.rb
index 168f217..3704c63 100644
--- a/lib/jcr/evaluate_array_rules.rb
+++ b/lib/jcr/evaluate_array_rules.rb
@@ -114,7 +114,7 @@ def self.evaluate_array_rule_ordered jcr, rule_atom, data, econs, behavior = nil
             else
               group_behavior = ArrayBehavior.new( behavior )
               group_behavior.last_index = array_index
-              retval = evaluate_array_rule( grule, rule_atom, data, econs, group_behavior )
+              retval = evaluate_rule( grule, rule_atom, data, econs, group_behavior )
               if retval.success
                 behavior.checked_hash.merge!( group_behavior.checked_hash )
                 array_index = group_behavior.last_index
@@ -129,7 +129,7 @@ def self.evaluate_array_rule_ordered jcr, rule_atom, data, econs, behavior = nil
             break if array_index == data.length
             group_behavior = ArrayBehavior.new( behavior )
             group_behavior.last_index = array_index
-            e = evaluate_array_rule( grule, rule_atom, data, econs, group_behavior )
+            e = evaluate_rule( grule, rule_atom, data, econs, group_behavior )
             if e.success
               behavior.checked_hash.merge!( group_behavior.checked_hash )
               array_index = group_behavior.last_index
@@ -209,7 +209,7 @@ def self.evaluate_array_rule_unordered jcr, rule_atom, data, econs, behavior = n
           group_behavior = ArrayBehavior.new( behavior )
           group_behavior.last_index = highest_index
           group_behavior.ordered = false
-          e = evaluate_array_rule( grule, rule_atom, data, econs, group_behavior )
+          e = evaluate_rule( grule, rule_atom, data, econs, group_behavior )
           if e.success
             highest_index = group_behavior.last_index
             behavior.checked_hash.merge!( group_behavior.checked_hash )
diff --git a/lib/jcr/evaluate_object_rules.rb b/lib/jcr/evaluate_object_rules.rb
index 2c5b143..eeb5edc 100644
--- a/lib/jcr/evaluate_object_rules.rb
+++ b/lib/jcr/evaluate_object_rules.rb
@@ -69,7 +69,7 @@ def self.evaluate_object_rule jcr, rule_atom, data, econs, behavior = nil
         successes = 0
         for i in 0..repeat_max
           group_behavior = ObjectBehavior.new
-          e = evaluate_object_rule( grule, rule_atom, data, econs, group_behavior )
+          e = evaluate_rule( grule, rule_atom, data, econs, group_behavior )
           if e.success
             behavior.checked_hash.merge!( group_behavior.checked_hash )
             successes = successes + 1
diff --git a/lib/jcr/evaluate_rules.rb b/lib/jcr/evaluate_rules.rb
index 5e1f105..6d701c3 100644
--- a/lib/jcr/evaluate_rules.rb
+++ b/lib/jcr/evaluate_rules.rb
@@ -23,10 +23,24 @@
 require 'jcr/map_rule_names'
 require 'jcr/check_groups'
 require 'jcr/evaluate_array_rules'
+require 'jcr/evaluate_object_rules'
 require 'jcr/evaluate_group_rules'
 require 'jcr/evaluate_member_rules'
 require 'jcr/evaluate_value_rules'
 
+
+# Adapted from Matt Sears
+class Proc
+  def jcr_callback(callable, *args)
+    self === Class.new do
+      method_name = callable.to_sym
+      define_method(method_name) { |&block| block.nil? ? true : block.call(*args) }
+      define_method("#{method_name}?") { true }
+      def method_missing(method_name, *args, &block) false; end
+    end.new
+  end
+end
+
 module JCR
 
   class Evaluation
@@ -50,26 +64,56 @@ def initialize mapping, callbacks
   end
 
   def self.evaluate_rule jcr, rule_atom, data, econs, behavior = nil
+    retval = Evaluation.new( false, "failed to evaluate rule properly" )
     case
+      when behavior.is_a?( ArrayBehavior )
+        retval = evaluate_array_rule( jcr, rule_atom, data, econs, behavior)
+      when behavior.is_a?( ObjectBehavior )
+        retval = evaluate_object_rule( jcr, rule_atom, data, econs, behavior)
       when jcr[:rule]
-        return evaluate_rule( jcr[:rule], rule_atom, data, econs, behavior)
+        retval = evaluate_rule( jcr[:rule], rule_atom, data, econs, behavior)
       when jcr[:target_rule_name]
         target = econs.mapping[ jcr[:target_rule_name][:rule_name].to_s ]
         raise "Target rule not in mapping. This should have been checked earlier." unless target
-        return evaluate_rule( target, target, data, econs, behavior )
+        retval = evaluate_rule( target, target, data, econs, behavior )
       when jcr[:primitive_rule]
-        return evaluate_value_rule( jcr[:primitive_rule], rule_atom, data, econs)
+        retval = evaluate_value_rule( jcr[:primitive_rule], rule_atom, data, econs)
       when jcr[:group_rule]
-        return evaluate_group_rule( jcr[:group_rule], rule_atom, data, econs, behavior)
+        retval = evaluate_group_rule( jcr[:group_rule], rule_atom, data, econs, behavior)
       when jcr[:array_rule]
-        return evaluate_array_rule( jcr[:array_rule], rule_atom, data, econs, behavior)
+        retval = evaluate_array_rule( jcr[:array_rule], rule_atom, data, econs, behavior)
       when jcr[:object_rule]
-        return evaluate_object_rule( jcr[:object_rule], rule_atom, data, econs, behavior)
+        retval = evaluate_object_rule( jcr[:object_rule], rule_atom, data, econs, behavior)
       when jcr[:member_rule]
-        return evaluate_member_rule( jcr[:member_rule], rule_atom, data, econs)
+        retval = evaluate_member_rule( jcr[:member_rule], rule_atom, data, econs)
       else
-        return Evaluation.new( true, nil )
+        retval = Evaluation.new( true, nil )
+    end
+    if jcr.is_a?( Hash ) && jcr[:rule_name]
+      rn = jcr[:rule_name].to_s
+      if econs.callbacks[ rn ]
+        retval = evaluate_callback( jcr, data, econs, rn, retval )
+      end
+    end
+    return retval
+  end
+
+  def self.evaluate_callback jcr, data, econs, callback, e
+    retval = e
+    c = econs.callbacks[ callback ]
+    if e.success
+      retval = c.jcr_callback :rule_eval_true, jcr, data
+    else
+      retval = c.jcr_callback :rule_eval_false, jcr, data, e
+    end
+    if retval.is_a? TrueClass
+      retval = Evaluation.new( true, nil )
+    elsif retval.is_a? FalseClass
+      retval = Evaluation.new( false, nil )
+    elsif retval.is_a? String
+      retval = Evaluation.new( false, retval )
     end
+    return retval
   end
 
   def self.get_repetitions rule
diff --git a/lib/jcr/jcr.rb b/lib/jcr/jcr.rb
index cb80901..d5425a4 100644
--- a/lib/jcr/jcr.rb
+++ b/lib/jcr/jcr.rb
@@ -26,7 +26,7 @@
 module JCR
 
   class Context
-    attr_accessor :mapping, :id, :tree, :roots, :catalog
+    attr_accessor :mapping, :callbacks, :id, :tree, :roots, :catalog
 
     def add_ruleset_alias( ruleset_alias, alias_uri )
       unless @catalog
@@ -60,6 +60,7 @@ def initialize( ruleset = nil )
       if ruleset
         ingested = JCR.ingest_ruleset( ruleset, false, nil )
         @mapping = ingested.mapping
+        @callbacks = ingested.callbacks
         @id = ingested.id
         @tree = ingested.tree
         @roots = ingested.roots
@@ -72,6 +73,10 @@ def override( ruleset )
       mapping.merge!( @mapping )
       mapping.merge!( overridden.mapping )
       overridden.mapping=mapping
+      callbacks = {}
+      callbacks.merge!( @callbacks )
+      callbacks.merge!( overridden.callbacks )
+      overridden.callbacks = callbacks
       overridden.roots.concat( @roots )
       return overridden
     end
@@ -79,6 +84,7 @@ def override( ruleset )
     def override!( ruleset )
       overridden = JCR.ingest_ruleset( ruleset, true, nil )
       @mapping.merge!( overridden.mapping )
+      @callbacks.merge!( overridden.callbacks )
       @roots.concat( overridden.roots )
     end
 
@@ -92,6 +98,7 @@ def self.ingest_ruleset( ruleset, override = false, ruleset_alias=nil )
     ctx = Context.new
     ctx.tree = tree
     ctx.mapping = mapping
+    ctx.callbacks = {}
     ctx.roots = roots
     JCR.process_directives( ctx )
     return ctx
@@ -113,7 +120,7 @@ def self.evaluate_ruleset( data, ctx, root_name = nil )
 
     retval = nil
     root_rules.each do |r|
-      retval = JCR.evaluate_rule( r, r, data, EvalConditions.new( ctx.mapping, nil ) )
+      retval = JCR.evaluate_rule( r, r, data, EvalConditions.new( ctx.mapping, ctx.callbacks ) )
       break if retval.success
     end
 
@@ -125,11 +132,11 @@ def self.main
     options = {}
 
     opt_parser = OptionParser.new do |opt|
-      opt.banner = "Usage: jcr [OPTIONS] [JSON_FILE]"
+      opt.banner = "Usage: jcr [OPTIONS] [JSON_FILES]"
       opt.separator  ""
       opt.separator  "Evaluates JSON against JSON Content Rules (JCR)."
       opt.separator  ""
-      opt.separator  "If JSON_FILE is not specified, standard input (STDIN) is used."
+      opt.separator  "If JSON_FILES is not specified, standard input (STDIN) is used."
       opt.separator  ""
       opt.separator  "Use -v to see results, otherwise check the exit code."
       opt.separator  ""
@@ -200,18 +207,40 @@ def self.main
           ctx.override!( ov )
         end
       end
-      data = JSON.parse( ARGF.read )
-      e = ctx.evaluate( data, options[:root_name] )
-      if e.success
-        if options[:verbose]
-          puts "Success!"
+
+      if $stdin.tty?
+        ec = 2
+        ARGV.each do |fn|
+          data = JSON.parse( File.open( fn ).read )
+          e = ctx.evaluate( data, options[:root_name] )
+          if e.success
+            if options[:verbose]
+              puts "Success!"
+            end
+            ec = 0
+          else
+            if options[:verbose]
+              puts "Failure: #{e.reason}"
+            end
+            ec = 1
+          end
         end
-        return 0
+        return ec
       else
-        if options[:verbose]
-          puts "Failure: #{e.reason}"
+        data = JSON.parse( ARGF.read )
+        e = ctx.evaluate( data, options[:root_name] )
+        if e.success
+          if options[:verbose]
+            puts "Success!"
+          end
+          return 0
+        else
+          if options[:verbose]
+            puts "Failure: #{e.reason}"
+          end
+          return 1
         end
-        return 1
+
       end
 
     end
diff --git a/spec/jcr_spec.rb b/spec/jcr_spec.rb
index 9b52744..f1fcb85 100644
--- a/spec/jcr_spec.rb
+++ b/spec/jcr_spec.rb
@@ -216,4 +216,165 @@
     expect( e.success ).to be_truthy
   end
 
+  it 'should callback eval_true once' do
+    ex = <<EX
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 1*2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+EX
+    my_eval_count = 0
+    c = Proc.new do |on|
+      on.rule_eval_true do |jcr,data|
+        my_eval_count = my_eval_count + 1
+        true
+      end
+    end
+    data = JSON.parse( '[ 1, "foo", "bar" ]')
+    ctx = JCR::Context.new( ex )
+    ctx.callbacks[ "my_integers" ] = c
+    e = ctx.evaluate( data )
+    expect( e.success ).to be_truthy
+    expect( my_eval_count ).to eq( 1 )
+  end
+
+  it 'should callback eval_true twice' do
+    ex = <<EX
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+EX
+    my_eval_count = 0
+    c = Proc.new do |on|
+      on.rule_eval_true do |jcr,data|
+        my_eval_count = my_eval_count + 1
+        true
+      end
+    end
+    data = JSON.parse( '[ 1, 2, "foo", "bar" ]')
+    ctx = JCR::Context.new( ex )
+    ctx.callbacks[ "my_integers" ] = c
+    e = ctx.evaluate( data )
+    expect( e.success ).to be_truthy
+    expect( my_eval_count ).to eq( 2 )
+  end
+
+  it 'should callback eval_false once' do
+    ex = <<EX
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+EX
+    my_eval_count = 0
+    c = Proc.new do |on|
+      on.rule_eval_false do |jcr,data,e|
+        my_eval_count = my_eval_count + 1
+        e
+      end
+    end
+    data = JSON.parse( '[ 3, 4, "foo", "bar" ]')
+    ctx = JCR::Context.new( ex )
+    ctx.callbacks[ "my_integers" ] = c
+    e = ctx.evaluate( data )
+    expect( e.success ).to be_falsey
+    expect( my_eval_count ).to eq( 1 )
+  end
+
+  it 'should callback eval_false twice by changing return value' do
+    ex = <<EX
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+my_integers :0..2
+my_strings ( :"foo" | :"bar" )
+
+EX
+    my_eval_count = 0
+    c = Proc.new do |on|
+      on.rule_eval_false do |jcr,data,e|
+        my_eval_count = my_eval_count + 1
+        true
+      end
+    end
+    data = JSON.parse( '[ 3, 4, "foo", "bar" ]')
+    ctx = JCR::Context.new( ex )
+    ctx.callbacks[ "my_integers" ] = c
+    e = ctx.evaluate( data )
+    expect( e.success ).to be_truthy
+    expect( my_eval_count ).to eq( 2 )
+  end
+
+  it 'should use callback to evaluate even numbers' do
+    ruleset = <<RULESET
+# ruleset-id rfcXXXX
+# jcr-version 0.5
+
+[ 2 my_integers, 2 my_strings ]
+
+; this will be the rule we custom validate
+my_integers :0..4
+
+my_strings ( :"foo" | :"bar" )
+
+RULESET
+
+    # Create a JCR context.
+    ctx = JCR::Context.new( ruleset )
+
+    # A local variable used in the callback closure
+    my_eval_count = 0
+
+    # The callback is created using a Proc object
+    c = Proc.new do |on|
+      validate = false
+
+      # called if the rule evaluates to true
+      # jcr is the rule
+      # data is the data being evaluated against the rule
+      on.rule_eval_true do |jcr,data|
+        my_eval_count = my_eval_count + 1
+        # return true if even number
+        validate = data.to_i % 2 == 0
+      end
+
+      # called if the rule evaluates to false
+      # jcr is the rule
+      # data is the data being evaluated against the rule
+      # e is the evaluation of the rule
+      on.rule_eval_false do |jcr,data,e|
+        my_eval_count = my_eval_count + 1
+        # return true if even number
+        validate = data.to_i % 2 == 0
+      end
+
+      # return the validation value
+      validate
+    end
+
+    # register the callback to be called for the "my_integers" rule
+    ctx.callbacks[ "my_integers" ] = c
+
+    data1 = JSON.parse( '[ 2, 4, "foo", "bar" ]')
+    e = ctx.evaluate( data1 )
+    expect(e.success).to be_truthy
+    expect(my_eval_count).to eq( 2 )
+
+    data2 = JSON.parse( '[ 3, 4, "foo", "bar" ]')
+    e = ctx.evaluate( data2 )
+    expect(e.success).to be_falsey
+    expect(my_eval_count).to eq( 3 )
+  end
+
 end
\ No newline at end of file