added in substring and startswith string functions

README.md

@@ -216,19 +216,19 @@ repositories {
 
 ```
 dependencies {
-	runtime(group: 'synapticloop', name: 'templar', version: '1.4.1', ext: 'jar')
+	runtime(group: 'synapticloop', name: 'templar', version: '1.4.2', ext: 'jar')
 
-	compile(group: 'synapticloop', name: 'templar', version: '1.4.1', ext: 'jar')
+	compile(group: 'synapticloop', name: 'templar', version: '1.4.2', ext: 'jar')
 }
 ```
 
 or, more simply for versions of gradle greater than 2.1
 
 ```
 dependencies {
-	runtime 'synapticloop:templar:1.4.1'
+	runtime 'synapticloop:templar:1.4.2'
 
-	compile 'synapticloop:templar:1.4.1'
+	compile 'synapticloop:templar:1.4.2'
 }
 ```
 
@@ -238,7 +238,7 @@ dependencies {
 <dependency>
 	<groupId>synapticloop</groupId>
 	<artifactId>templar</artifactId>
-	<version>1.4.1</version>
+	<version>1.4.2</version>
 	<type>jar</type>
 </dependency>
 ```

build.gradle

@@ -20,7 +20,7 @@ plugins {
 group = 'synapticloop'
 archivesBaseName = 'templar'
 description = """Templar templating engine"""
-version = '1.4.1'
+version = '1.4.2'
 
 sourceCompatibility = 1.7
 targetCompatibility = 1.7

src/main/java/synapticloop/templar/function/string/FunctionStartsWith.java

@@ -0,0 +1,41 @@
+package synapticloop.templar.function.string;
+
+import synapticloop.templar.exception.FunctionException;
+import synapticloop.templar.function.Function;
+import synapticloop.templar.helper.ObjectHelper;
+import synapticloop.templar.utils.TemplarContext;
+
+/*
+ * Copyright (c) 2017 Synapticloop.
+ * 
+ * All rights reserved.
+ * 
+ * This code may contain contributions from other parties which, where 
+ * applicable, will be listed in the default build file for the project 
+ * ~and/or~ in a file named CONTRIBUTORS.txt in the root of the project.
+ * 
+ * This source code and any derived binaries are covered by the terms and 
+ * conditions of the Licence agreement ("the Licence").  You may not use this 
+ * source code or any derived binaries except in compliance with the Licence.  
+ * A copy of the Licence is available in the file named LICENSE.txt shipped with 
+ * this source code or binaries.
+ */
+
+public class FunctionStartsWith extends Function {
+
+	public FunctionStartsWith() {
+		super(2);
+	}
+
+	@Override
+	protected Object evaluateFunction(Object[] args, TemplarContext templarContext) throws FunctionException {
+		Object argZero = ObjectHelper.evaluateObjectToDefault(args[0], templarContext);
+		Object argOne = ObjectHelper.evaluateObjectToDefault(args[1], templarContext);
+		if(null == argZero || null == argOne) {
+			throw new FunctionException("Could not evaluate arguments to String, arguments were: " + args[0] + ", " + args[1] + ", values: " + argZero + ", " + argOne);
+		}
+
+		return(argOne.toString().startsWith(argZero.toString()));
+	}
+
+}

src/main/java/synapticloop/templar/function/string/FunctionSubString.java

@@ -2,19 +2,45 @@
 
 import synapticloop.templar.exception.FunctionException;
 import synapticloop.templar.function.Function;
+import synapticloop.templar.helper.ObjectHelper;
 import synapticloop.templar.utils.TemplarContext;
 
 public class FunctionSubString extends Function {
 
 	public FunctionSubString() {
-		super(3);
+		super(2, 3);
 	}
 
 	@Override
 	protected Object evaluateFunction(Object[] args, TemplarContext templarContext) throws FunctionException {
-		// arguments can be either 2 or 3
-		// TODO Auto-generated method stub
-		return null;
+		Object argZero = ObjectHelper.evaluateObjectToDefault(args[0], templarContext);
+		Object argOne = ObjectHelper.evaluateObjectToDefault(args[1], templarContext);
+
+		int from = 0;
+		int to = 0;
+
+		try {
+			from = Integer.parseInt(argOne.toString());
+		} catch(NumberFormatException ex) {
+			throw new FunctionException("Could not evaluate arguments to Integer, arguments was: " + args[1] + ", value: " + argOne);
+		}
+
+		Object argTwo = null;
+		if(args.length == 3) {
+			argTwo = ObjectHelper.evaluateObjectToDefault(args[2], templarContext);
+			try {
+				to = Integer.parseInt(argTwo.toString());
+			} catch(NumberFormatException ex) {
+				throw new FunctionException("Could not evaluate arguments to Integer, arguments was: " + args[2] + ", value: " + argTwo);
+			}
+		}
+
+		// at this point we should be good to go
+		if(args.length == 3) {
+			return(argZero.toString().substring(from, to));
+		} else {
+			return(argZero.toString().substring(from));
+		}
 	}
 
 }

src/main/java/synapticloop/templar/utils/TemplarContext.java

@@ -48,6 +48,8 @@
 import synapticloop.templar.function.math.FunctionPower;
 import synapticloop.templar.function.math.FunctionSubtract;
 import synapticloop.templar.function.string.FunctionIndexOf;
+import synapticloop.templar.function.string.FunctionStartsWith;
+import synapticloop.templar.function.string.FunctionSubString;
 import synapticloop.templar.function.string.FunctionToJson;
 import synapticloop.templar.function.util.FunctionInstanceOf;
 
@@ -104,9 +106,10 @@ public class TemplarContext {
 		// string
 		functionMap.put("indexOf", new FunctionIndexOf()); // get the index of strings
 		functionMap.put("toJson", new FunctionToJson()); // convert a string into a JSON object
-		// NIY
-//		functionMap.put("substring", new FunctionSubString()); // get the substring
-}
+		functionMap.put("startsWith", new FunctionStartsWith()); // determine whether a string starts with another string
+		functionMap.put("substring", new FunctionSubString()); // return a substring of a string
+
+	}
 
 	private static Map<String, String> functionAliasMap = new HashMap<String, String>();
 	static {

src/test/java/synapticloop/templar/function/string/FunctionSubStringTest.java

@@ -0,0 +1,28 @@
+package synapticloop.templar.function.string;
+import static org.junit.Assert.*;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import synapticloop.templar.exception.FunctionException;
+
+public class FunctionSubStringTest {
+	private FunctionSubString functionSubString = null;
+
+	@Before
+	public void setup() {
+		functionSubString = new FunctionSubString();
+	}
+
+	@Test
+	public void testSubstring() throws FunctionException {
+		Object evaluate = functionSubString.evaluate("substring", new Object[] { "\"hello\"", "\"1\"" }, null);
+		assertEquals("ello", evaluate);
+	}
+
+	@Test
+	public void testSubstringRange() throws FunctionException {
+		Object evaluate = functionSubString.evaluate("substring", new Object[] { "\"hello\"", "\"1\"", "\"3\"" }, null);
+		assertEquals("el", evaluate);
+	}
+}