{"id":822,"date":"2006-07-20T04:02:58","date_gmt":"2006-07-20T08:02:58","guid":{"rendered":"http:\/\/wordpress.cephas.net\/?p=822"},"modified":"2006-07-20T04:02:58","modified_gmt":"2006-07-20T08:02:58","slug":"fluentinterface","status":"publish","type":"post","link":"https:\/\/cephas.net\/blog\/2006\/07\/20\/fluentinterface\/","title":{"rendered":"FluentInterface"},"content":{"rendered":"

A couple of weeks ago on the DWR users list<\/a>, in the context of needing to wire up DWR without using an XML file, Joe Walker<\/a> pointed to a blog posting<\/a> by Martin Fowler<\/a>. In it, Martin discusses an interface style called a ‘fluent interface’. It’s a little difficult to describe in words (so check it out in action on above mentioned blog post) but I think Piers Cawley<\/a> described it best<\/a> when he described the style as “…essentially interfaces that do a good job of removing hoopage.” Update:<\/strong> Geert Bevin uses this style in the RIFE framework<\/a> and was calling the it “chainable builder methods” before Martin came along with the ‘fluent interface’ term.<\/p>\n

Back to DWR.  I spent the last couple days working on a ‘fluent’ way of configuring DWR which obviously then wouldn’t require dwr.xml<\/a>, the result of which is available here<\/a>. In short, given an XML configuration file that looks like this:
\n
\n<?xml version=\"1.0\" encoding=\"UTF-8\"?>
\n<!DOCTYPE dwr PUBLIC \"-\/\/GetAhead Limited\/\/DTD Direct Web Remoting
\n1.0\/\/EN\" \"http:\/\/www.getahead.ltd.uk\/dwr\/dwr10.dtd\">
\n<dwr>
\n  <init>
\n    <converter id=\"testbean\" class=\"uk.ltd.getahead.testdwr.TestBean2Converter\"\/>
\n  <\/init>
\n  <allow>
\n    <create creator=\"new\" javascript=\"Test\" scope=\"application\">
\n      <param name=\"class\" value=\"uk.ltd.getahead.testdwr.Test\"\/>
\n    <\/create>
\n    <create creator=\"new\" javascript=\"JDate\">
\n      <param name=\"class\" value=\"java.util.Date\"\/>
\n      <exclude method=\"getHours\"\/>
\n      <auth method=\"getMinutes\" role=\"admin\"\/>
\n      <auth method=\"getMinutes\" role=\"devel\"\/>
\n    <\/create>
\n    <convert converter=\"bean\" match=\"$Proxy*\"\/>
\n    <convert converter=\"testbean\" match=\"uk.ltd.getahead.testdwr.TestBean\"\/>
\n    <convert converter=\"bean\" match=\"uk.ltd.getahead.testdwr.ObjB\"\/>
\n    <convert converter=\"object\" match=\"uk.ltd.getahead.testdwr.ObjA\">
\n      <param name=\"force\" value=\"true\"\/>
\n    <\/convert>
\n  <\/allow>
\n  <signatures>
\n  <![CDATA[
\n  import java.util.*;
\n  import uk.ltd.getahead.testdwr.*;
\n  Test.testBeanSetParam(Set<TestBean>);
\n  Test.testBeanListParam(List<TestBean>);
\n  Test.charTestBeanMapParam(Map<Character, TestBean>);
\n  Test.stringStringMapParam(Map<String, String>);
\n  Test.stringStringHashMapParam(HashMap<String, String>);
\n  Test.stringStringTreeMapParam(TreeMap<String, String>);
\n  Test.stringCollectionParam(Collection<String>);
\n  Test.stringListParam(List<String>);
\n  Test.stringLinkedListParam(LinkedList<String>);
\n  Test.stringArrayListParam(ArrayList<String>);
\n  Test.stringSetParam(Set<String>);
\n  Test.stringHashSetParam(HashSet<String>);
\n  Test.stringTreeSetParam(TreeSet<String>);
\n  ]]>
\n  <\/signatures>
\n<\/dwr>
\n<\/code>
\nyou can instead configure DWR using the FluentConfiguration class like this:
\n
\nFluentConfiguration fluentconfig = (FluentConfiguration)configuration;
\nfluentconfig
\n  .withConverterType(\"testbean\", \"uk.ltd.getahead.testdwr.TestBean2Converter\")
\n  .withCreator(\"new\", \"Test\")
\n    .addParam(\"scope\", \"application\")
\n    .addParam(\"class\", \"uk.ltd.getahead.testdwr.Test\")
\n  .withCreator(\"new\", \"JDate\")
\n    .addParam(\"class\", \"java.util.Date\")
\n    .exclude(\"getHours\")
\n    .withAuth(\"getMinutes\", \"admin\")
\n    .withAuth(\"getMinutes\", \"devel\")
\n  .withConverter(\"bean\", \"$Proxy*\")
\n  .withConverter(\"testbean\", \"uk.ltd.getahead.testdwr.TestBean\")
\n  .withConverter(\"bean\", \"uk.ltd.getahead.testdwr.ObjB\")
\n  .withConverter(\"object\", \"uk.ltd.getahead.testdwr.ObjA\")
\n    .addParam(\"force\", \"true\")
\n  .withSignature()
\n    .addLine(\"import java.util.*;\")
\n    .addLine(\"import uk.ltd.getahead.testdwr.*;\")
\n    .addLine(\"Test.testBeanSetParam(Set);\")
\n    .addLine(\"Test.testBeanListParam(List);\")
\n    .addLine(\"Test.charTestBeanMapParam(Map);\")
\n    .addLine(\"Test.stringStringMapParam(Map);\")
\n    .addLine(\"Test.stringStringHashMapParam(HashMap);\")
\n    .addLine(\"Test.stringStringTreeMapParam(TreeMap);\")
\n    .addLine(\"Test.stringCollectionParam(Collection);\")
\n    .addLine(\"Test.stringListParam(List);\")
\n    .addLine(\"Test.stringLinkedListParam(LinkedList);\")
\n    .addLine(\"Test.stringArrayListParam(ArrayList);\")
\n    .addLine(\"Test.stringSetParam(Set);\")
\n    .addLine(\"Test.stringHashSetParam(HashSet);\")
\n    .addLine(\"Test.stringTreeSetParam(TreeSet);\")
\n  .finished();
\n<\/code>
\nIf you’re interested in using this in your DWR project, you need only to:<\/p>\n

  • create a class that extends DWRServlet (example: check out FluentDWRServlet.java in the zip file) and use that class as your DWR servlet\n
  • add a configuration param in web.xml called uk.ltd.getahead.dwr.Configuration and set the value to net.cephas.dwr.FluentConfiguration\n
  • add a configuration param in web.xml called skipDefaultConfig and set the value to true
    \n
    \n<servlet>
    \n  <servlet-name>dwr<\/servlet-name>
    \n  <servlet-class>net.cephas.dwr.FluentDWRServlet<\/servlet-class>
    \n    <init-param>
    \n      <param-name>uk.ltd.getahead.dwr.Configuration<\/param-name>
    \n      <param-value>net.cephas.dwr.FluentConfiguration<\/param-value>
    \n    <\/init-param>
    \n    <init-param>
    \n      <param-name>skipDefaultConfig<\/param-name>
    \n      <param-value>true<\/param-value>
    \n    <\/init-param>
    \n<\/servlet>
    \n<\/code><\/p>\n
  • and then override the configure method in the servlet and use the fluent style of configuration I used above.\n

    Send me an email<\/a> if you have any questions!<\/p>\n","protected":false},"excerpt":{"rendered":"

    A couple of weeks ago on the DWR users list, in the context of needing to wire up DWR without using an XML file, Joe Walker pointed to a blog posting by Martin Fowler. In it, Martin discusses an interface style called a ‘fluent interface’. It’s a little difficult to describe in words (so check … Continue reading FluentInterface<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3,29,2,10],"tags":[],"_links":{"self":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts\/822"}],"collection":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/comments?post=822"}],"version-history":[{"count":0,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts\/822\/revisions"}],"wp:attachment":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/media?parent=822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/categories?post=822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/tags?post=822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}