Add system.util.evalExpression

common/src/main/java/org/imdc/extensions/common/UtilitiesExtensions.java

@@ -1,12 +1,29 @@
 package org.imdc.extensions.common;
 
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 import com.inductiveautomation.ignition.common.PyUtilities;
+import com.inductiveautomation.ignition.common.TypeUtilities;
+import com.inductiveautomation.ignition.common.expressions.ConstantExpression;
+import com.inductiveautomation.ignition.common.expressions.Expression;
+import com.inductiveautomation.ignition.common.expressions.ExpressionParseContext;
+import com.inductiveautomation.ignition.common.expressions.FunctionFactory;
+import com.inductiveautomation.ignition.common.expressions.parsing.ELParserHarness;
 import com.inductiveautomation.ignition.common.model.CommonContext;
+import com.inductiveautomation.ignition.common.model.values.QualifiedValue;
 import com.inductiveautomation.ignition.common.script.PyArgParser;
+import com.inductiveautomation.ignition.common.script.ScriptContext;
 import com.inductiveautomation.ignition.common.script.builtin.KeywordArgs;
 import com.inductiveautomation.ignition.common.script.hints.ScriptFunction;
+import com.inductiveautomation.ignition.common.tags.model.TagPath;
+import com.inductiveautomation.ignition.common.tags.paths.parser.TagPathParser;
 import org.apache.commons.lang3.tuple.Pair;
 import org.jetbrains.annotations.NotNull;
 import org.python.core.Py;
@@ -17,6 +34,8 @@
 public class UtilitiesExtensions {
     private final CommonContext context;
 
+    private static final ELParserHarness EXPRESSION_PARSER = new ELParserHarness();
+
     public UtilitiesExtensions(CommonContext context) {
         this.context = context;
     }
@@ -55,4 +74,59 @@ private static PyObject recursiveConvert(@NotNull PyObject object) {
             }
         }
     }
+
+    @ScriptFunction(docBundlePrefix = "UtilitiesExtensions")
+    @KeywordArgs(names = {"expression"}, types = {String.class})
+    public QualifiedValue evalExpression(PyObject[] args, String[] keywords) throws Exception {
+        if (args.length == 0) {
+            throw Py.ValueError("Must supply at least one argument to evalExpression");
+        }
+
+        String expression = TypeUtilities.toString(TypeUtilities.pyToJava(args[0]));
+
+        var keywordMap = new HashMap<String, Object>();
+        for (int i = 0; i < keywords.length; i++) {
+            keywordMap.put(keywords[i], TypeUtilities.pyToJava(args[i + 1]));
+        }
+        ExpressionParseContext parseContext = new KeywordParseContext(keywordMap);
+
+        Expression actualExpression = EXPRESSION_PARSER.parse(expression, parseContext);
+        try {
+            actualExpression.startup();
+            return actualExpression.execute();
+        } finally {
+            actualExpression.shutdown();
+        }
+    }
+
+    private class KeywordParseContext implements ExpressionParseContext {
+        private final Map<String, Object> keywords;
+
+        private KeywordParseContext(Map<String, Object> keywords) {
+            this.keywords = keywords;
+        }
+
+        @Override
+        public Expression createBoundExpression(String reference) throws RuntimeException {
+            if (reference == null || reference.isEmpty()) {
+                throw new IllegalArgumentException("Invalid path " + reference);
+            }
+            if (keywords.containsKey(reference)) {
+                return new ConstantExpression(keywords.get(reference));
+            } else {
+                try {
+                    TagPath path = TagPathParser.parse(ScriptContext.defaultTagProvider(), reference);
+                    var tagValues = context.getTagManager().readAsync(List.of(path)).get(30, TimeUnit.SECONDS);
+                    return new ConstantExpression(tagValues.get(0).getValue());
+                } catch (IOException | InterruptedException | ExecutionException | TimeoutException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
+
+        @Override
+        public FunctionFactory getFunctionFactory() {
+            return context.getExpressionFunctionFactory();
+        }
+    }
 }

common/src/main/resources/org/imdc/extensions/common/UtilitiesExtensions.properties

@@ -1,6 +1,8 @@
 getContext.desc=Returns the current scope's context object directly.
 getContext.returns=The current scope's context.
-
 deepCopy.desc=Deep copies the inner object structure into plain Python lists, dictionaries, and primitives.
 deepCopy.param.object=The object to convert.
 deepCopy.returns=A plain Python primitive object.
+evalExpression.desc=Evaluates the supplied expression. Provide keyword arguments to populate values to curly braces.
+evalExpression.param.expression=The expression to evaluate.
+evalExpression.returns=A QualifiedValue with the result of the provided expression.

docker-compose.yml

@@ -3,6 +3,7 @@ services:
     image: inductiveautomation/ignition:8.1.20
     ports:
       - 18088:8088
+      - 18000:8000
     environment:
       GATEWAY_ADMIN_PASSWORD: password
       IGNITION_EDITION: standard