Update README-RULE.md for new architecture / guidance (#780)

accessibility-checker-engine/README-RULES.md

@@ -14,28 +14,28 @@ Multiple objects are needed for a rule to fire and show up in the tool results:
 ### Rule object
 
 The basic rule format is defined by the Rule type in [src/v4/api/IRule.ts](src/v4/api/IRule.ts). Rule implementation is located in [src/v4/rules](src/v4/rules).  The rule context, including DOM object hierarchies, attributes, explicit/implicit CSS and ARIA attributes, that may trigger a rule, are defined in [src/v2/common/Context.ts](src/v2/common/Context.ts). The rule results can be one of:
-* RulePass("MSG_ID")
-* RuleFail("MSG_ID")
-* RulePotential("MSG_ID")
-* RuleManual("MSG_ID")
+* RulePass("pass_reason")
+* RuleFail("fail_reason")
+* RulePotential("potential_reason")
+* RuleManual("manual_reason")
 
 Each of these can take message arguments as a string array in the second parameter. They may also pass parameters to other APIs as an array in the third argument.
 
 An example rule might look like:
 ```
 {
-    id: "TRIGGER_ALL_BODY",
+    id: "body_all_trigger",
     context: "dom:body",
     help: {
         "en-US": {
-            0: `TRIGGER_ALL_BODY.html`,
-            "Pass_0": `TRIGGER_ALL_BODY.html`
+            0: `body_all_trigger.html`,
+            "Pass_0": `body_all_trigger.html`
         }
     },
     messages: {
         "en-US": {
             "group": "Grouping label for the rule",
-            "Pass_0": "Check the body element for something"
+            "manual_always": "Check the body element for something"
         }
     },
     rulesets: [{
@@ -49,7 +49,7 @@ An example rule might look like:
         const ruleContext = context["dom"].node as Element;
         const domAttrs = context["dom"].attributes;
 
-        return return RuleManual("Pass_0");
+        return RuleManual("manual_always");
     }
 }
 ```
@@ -69,19 +69,19 @@ Each rule may have one or more test cases. Test cases are located in [test/v2/ch
 
     <script type="text/javascript">
         UnitTest = {
-            ruleIds: ["TRIGGER_ALL_BODY"],
+            ruleIds: ["body_all_trigger"],
             results: [{
-                "ruleId": "TRIGGER_ALL_BODY",
+                "ruleId": "body_all_trigger",
                 "category": "Accessibility",
                 "value": [
-                    "INFORMATION", "FAIL"
+                    "INFORMATION", "MANUAL"
                 ],
                 "path": {
                     "dom": "/html[1]/body[1]",
                     "aria": "/document[1]"
                 },
-                "reasonId": "Fail_1",
-                "message": "Another message with message code Fail_1.",
+                "reasonId": "manual_always",
+                "message": "Check the body element for something",
                 "messageArgs": [],
                 "apiArgs": []
             }]
@@ -119,8 +119,7 @@ Note: Rule changes are not automatically rebuilt. You will have to kill the rule
 ## Summary of steps to implement/update and test a new rule
 
 * Create a rule id for a new rule. 
-* Create the rule and ruleset mapping to [src/v2/checker/accessibility/rulesets/index.ts](src/v2/checker/accessibility/rulesets/index.ts). 
 * Create the help file in [help-v4](help-v4).
-* Create the rule implementation in [src/v4/rules](src/v4/rules). The rule implementation includes the rule context, logic and outcome (Pass or Fail).
+* Create the rule implementation in [src/v4/rules](src/v4/rules). The rule implementation includes the rule context, message, help, ruleset mappings, logic and outcome.
 * Create test cases for the rule in [test/v2/checker/accessibility/rules](test/v2/checker/accessibility/rules).
-* Test the rules with the test cases. You may run the test cases locally, or run with the local rule server. 
+* Test the rules with the test cases. You may run the test cases locally, or run with the local rule server.