README.md in fluent-plugin-xml-parser-0.0.4 vs README.md in fluent-plugin-xml-parser-0.0.5

@@ -16,40 +16,51 @@
 
     $ gem install fluent-plugin-xml-parser
 
 ## Usage
 
-fluent-plugin-xml-parser provides input data conversion from XML to JSON for
-simple case, like sensor data. It can be specified at source directive as
-'format' option.
+Fluent::Plugin::XmlParser provides input data conversion from simple XML data
+like sensor data into Ruby hash structure for emitting next procedure in fluentd.
+In order to enable Fluent::Plugin::XmlParser, 'format xml' option needs to be
+specified at 'source' directive.
 
-The followings are an example description for Libelium SmartCity sensor data.
+The followings are an example configuration for reformatting Libelium SmartCity sensor data to fit ElasticSearch received via MQTT protocol([fluent-plugin-mqtt-io](https://github.com/toyokazu/fluent-plugin-mqtt-io)).
 
 ```
 
 <source>
   type mqtt
   bind 127.0.0.1
-  port 1883
+  port 11883
+  topic 'Libelium/+/#'
   format xml
   time_xpath '["cap:alert/cap:info/cap:onset", "text"]'
-  attr_xpaths '[[null, "description"], ["cap:alert/cap:info/cap:parameter/cap:valueName", "text"]]'
-  value_xpaths '[["cap:alert/cap:info/cap:description", "text"], ["cap:alert/cap:info/cap:parameter/cap:value", "text"]]'
+  time_key '@timestamp'
+  attr_xpaths '[["cap:alert/cap:info/cap:parameter/cap:valueName", "text"]]'
+  value_xpaths '[["cap:alert/cap:info/cap:parameter/cap:value", "text"]]'
+  @label @MQTT_OUT
 </source>
 
 ```
 
-time_xpath specifies timestamp filed value. An array with two strings means xpath of
-the value and the attribute of the XML element (name, text etc).
+Configurable options are the following:
 
-attr_xpaths indicates attribute name of the target value. Each array with two strings
-means xpath of the attribute name and the attribute of the XML element (name, text etc).
-XPath can be omitted as 'null' and specify your own attribute name as the second
-parameter.
-
-value_xpaths indicates the target value to be extracted. Each array with two strings
-means xpath of the target value and the attribute of the XML element (name, text etc).
-XPath can be omitted as 'null' and specify your own value as the second parameter.
+- **time_xpath**: A value for fluentd time field. An array with two strings means xpath of
+  the value and the attribute of the XML element (name, text etc). If this option is
+  omitted, current time is used.
+- **time_key**: An attribute name of extra timestamp field appended to the record. If Output
+  Plugin does not provide timestamp configuration, you can specify field name by this option.
+  If this option is omitted, extra timestamp field is not appended.
+- **time_format**: You can specify time format. If this is omitted, ISO8601 format is used.
+- **attr_xpaths**: indicates attribute name of the target value. Each array with two strings
+  means xpath of the attribute name and the attribute of the XML element (name, text etc).
+  XPath can be omitted as 'null' and specify your own attribute name as the second
+  parameter.
+- **value_xpaths**: indicates the target value to be extracted. Each array with two strings
+  means xpath of the target value and the attribute of the XML element (name, text etc) and
+  each value is stored into the Hash with the key specified at an array instance in the
+  **attr_xpaths** with the same index. XPath can be omitted as 'null' and specify your own
+  value as the second parameter.
 
 The extracted fields are packed into Hash structure (record field) to emit the next procedure in fluentd.
 
 You can check your own XML data structure by using irb or pry