Issue 450. Inverse bounded range support.

spec/VISSv2_Core.html

@@ -662,12 +662,35 @@ <h2>Time Based Filter Operation</h2>
      <section id="range-filter-operation">
           <h2>Range Filter Operation</h2>
                 <p>
-                The value contains the range boundary, and the logical operator, {"logic-op":"X", "boundary": "Y"}, 
-                where X is one of the supported logical operators (**), and Y is the boundary of the range.
-                The value may be an array of two of these objects, 
-                which will then be combined through a logical AND to support expressions of a bounded range. 
-                A range event is triggered whenever a signal is updated, and fulfilling the range expression.<br><br>
-                (**)The supported logical operators are ["eq", "ne", "gt", "gte", "lt", "lte"], 
+                The range filter operation supports two types of ranges, see the following sub chapters.<br>
+                <section id="single-boundary-range">
+                  <h2>Single Boundary Range</h2>
+                  <p>
+                  One logical "boundary operator" evaluates the current signal value in relation to the boundary. 
+                  If evaluated to true, the server issues a notification message containing the signal value to the subscribing client. 
+                  The boundary operator MUST be one of the values shown in the footer (**).<br>
+                  Examples<br>
+                  {"boundary-op":"gt", "boundary": "5"}   // x > 5<br>
+                  {"boundary-op":"eq", "boundary": "5"}   // x == 5
+                  </p>
+                </section>
+                <section id="multi-boundary-range">
+                  <h2>Multi Boundary Range</h2>
+                  <p>
+                  Two boundaries with respective boundary operators are evaluated relative to the current signal value. 
+                  The logical outcome of the two evaluations are applied as input to a logical AND/OR operation. 
+                  If evaluated to true, the server issues a notification message containing the signal value to the subscribing client. 
+                  Besides the mandatory "boundary-op", and "boundary" key-value pairs in each JSON object, 
+                  the first object may contain a "combination-op" key value pair, which then MUST have either the value "AND", or the value "OR". 
+                  If omitted, the result of the two boundary evaluations is per default applied to an AND operation. 
+                  The JSON array MUST contain two objects. 
+                  The boundary operator MUST be one of the values shown in the footer (**).<br>
+                  Examples<br>
+                  [{"boundary-op":"gt", "boundary": "5"},{"boundary-op":"lt", "boundary": "10"}]   // x > 5 AND x < 10<br>
+                  [{"boundary-op":"lt", "boundary": "5", "combination-op":"OR"},{"boundary-op":"gt", "boundary": "10"}]   // x < 5 OR x > 10
+                  </p>
+                </section>
+                (**)The supported boundary operators are ["eq", "ne", "gt", "gte", "lt", "lte"], 
                 where "eq" is "equal", "ne" is "not equal", "gt" is "greater than", "gte" is "greater than or equal", "lt" is "less than", 
                 "lte" is "less than or equal".<br>
                 Examples can be found in the <a data-link-type="dfn" href="https://www.w3.org/TR/viss2-transport/#authorized-subscribe">authorized subscribe</a> and 
@@ -685,7 +708,7 @@ <h2>Change Filter Operation</h2>
                 "value":{"logic-op":"lt", "diff": "0"} This leads to a trigger event when the value goes true->false.<br>
                 "value":{"logic-op":"ne", "diff": "0"} This leads to a trigger event when the value goes true->false OR false->true.
                 <br><br>
-                (**)The supported logical operators are ["eq", "ne", "gt", "gte", "lt", "lte"], 
+                (**)The supported logic operators are ["eq", "ne", "gt", "gte", "lt", "lte"], 
                 where "eq" is "equal", "ne" is "not equal", "gt" is "greater than", "gte" is "greater than or equal", 
                 "lt" is "less than", "lte" is "less than or equal".<br>
                 Examples can be found in the [[viss2-transport]] specification.

spec/VISSv2_Transport.html

@@ -1168,7 +1168,7 @@ <h2>Authorized Subscribe</h2>
               {
                 "action": "subscribe",
                 "path": "Vehicle/Drivetrain/FuelSystem/Level",
-                "filter": {"type":"range", "value":[{"logic-op":"gt", "boundary":"49"}, {"logic-op":"lt", "boundary":"51"}]},
+                "filter": {"type":"range", "value":[{"boundary-op":"gt", "boundary":"49"}, {"boundary-op":"lt", "boundary":"51"}]},
                 "authorization": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1...Zw_KSsds",
                 "requestId": "6578"
               }
@@ -1239,7 +1239,7 @@ <h2>Curve Logging Subscribe</h2>
           <section id="range-subscribe">
             <h2>Range Subscribe</h2>
             <p>
-            Subscription to a range of values, that can be either unbounded, or bounded as in the example below. 
+            Subscription to a range of values, that can have either a single boundary, or multipe boundaries as in the example below. 
             For a more information how to use range of values, refer the Range Filter Operation chapter in the [[viss2-core]] documentation.
             </p>
             <p>
@@ -1249,7 +1249,7 @@ <h2>Range Subscribe</h2>
               {
                 "action": "subscribe",
                 "path": "Vehicle/Drivetrain/FuelSystem/Level",
-                "filter": "filter":{"type":"range","value":[{"logic-op":"gt","boundary":"50"},{"logic-op":"lt","boundary":"55"}]},
+                "filter": "filter":{"type":"range","value":[{"boundary-op":"lt","boundary":"50","combination-op":"OR"},{"boundary-op":"gt","boundary":"55"}]},
                 "requestId": "6578"
               }
                </code></pre>
@@ -1274,6 +1274,45 @@ <h2>Range Subscribe</h2>
                </code></pre>
             </p>
           </section>
+
+          <section id="change-subscribe">
+            <h2>Change Subscribe</h2>
+            <p>
+            Subscription to when a signal has changed between two sequential captures. 
+            For a more information how to use change of values, refer the Change Filter Operation chapter in the [[viss2-core]] documentation.
+            </p>
+            <p>
+              <b>Example:</b><br>
+              Request:
+              <pre><code>
+              {
+                "action": "subscribe",
+                "path": "Vehicle/Drivetrain/FuelSystem/Level",
+                "filter": "filter":{"type":"change","value":{"logic-op":"gt","diff":"10"}},
+                "requestId": "6578"
+              }
+               </code></pre>
+              Successful response:
+              <pre><code>
+              {
+                "action": "subscribe",
+                "subscriptionId": "12345",
+                "requestId": "6578",
+                "ts": "2020-04-15T13:37:00Z"
+              }
+               </code></pre>
+              Notification:
+              <pre><code>
+              {
+                "action": "subscription",
+                "subscriptionId": "12345",
+                “data”:{“path”: ”Vehicle/Drivetrain/FuelSystem/Level”, 
+                        “dp”:{“value”: ”101”, “ts”: ”2020-04-15T14:00:00Z”},
+                "ts": "2020-04-15T14:00:00Z"
+              }
+               </code></pre>
+            </p>
+          </section>
           </section>
 
           <section id="unsubscribe">