libs/dnet-wf-service/src/main/java/eu/dnetlib/manager/wf/workflows/graph/GraphLoader.java

@@ -6,7 +6,11 @@ import java.util.Set;
 
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.expression.MapAccessor;
 import org.springframework.core.env.Environment;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.stereotype.Service;
 
 import com.google.common.base.Function;
@@ -64,8 +68,14 @@ public class GraphLoader {
 	}
 
 	private Function<Env, Boolean> generateFunction(final String condition) {
-		// TODO Auto-generated method stub
-		return null;
+		return env -> {
+			final ExpressionParser parser = new SpelExpressionParser();
+
+			final StandardEvaluationContext context = new StandardEvaluationContext(env.getAttributes());
+			context.addPropertyAccessor(new MapAccessor());
+
+			return parser.parseExpression(condition).getValue(context, Boolean.class);
+		};
 	}
 
 	private void checkValidity(final Graph graph) throws WorkflowManagerException {

libs/dnet-wf-service/src/test/java/eu/dnetlib/manager/wf/workflows/graph/GraphLoaderTest.java

@@ -0,0 +1,54 @@
+package eu.dnetlib.manager.wf.workflows.graph;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.function.Function;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.context.expression.MapAccessor;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+
+import eu.dnetlib.manager.wf.workflows.procs.Env;
+
+public class GraphLoaderTest {
+
+	private Env env;
+
+	@BeforeEach
+	void setUp() throws Exception {
+		env = new Env();
+		env.setAttribute("author", "Michele Artini");
+		env.setAttribute("age", 47);
+	}
+
+	@Test
+	final void testExpressions() {
+		assertTrue(evalFunction("age == 47").apply(env));
+		assertTrue(evalFunction("age > 40").apply(env));
+		assertTrue(evalFunction("author == 'Michele Artini'").apply(env));
+		assertTrue(evalFunction("age == 47 && author == 'Michele Artini'").apply(env));
+		assertTrue(evalFunction("age == 47 || author == 'Michele Artini'").apply(env));
+		assertTrue(evalFunction("age == 47 || author == 'Claudio Atzori'").apply(env));
+		assertTrue(evalFunction("age == 22 || author == 'Michele Artini'").apply(env));
+		assertFalse(evalFunction("age != 47").apply(env));
+		assertFalse(evalFunction("age < 40").apply(env));
+		assertFalse(evalFunction("author != 'Michele Artini'").apply(env));
+		assertFalse(evalFunction("age == 47 && author == 'Claudio Atzori'").apply(env));
+	}
+
+	private Function<Env, Boolean> evalFunction(final String f) {
+		return env -> {
+			final ExpressionParser parser = new SpelExpressionParser();
+
+			final StandardEvaluationContext context = new StandardEvaluationContext(env.getAttributes());
+			context.addPropertyAccessor(new MapAccessor());
+
+			return parser.parseExpression(f).getValue(context, Boolean.class);
+		};
+	}
+
+}