From 5a704af88b91a83ad78b5fb6dc3147a9b65d713d Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Mon, 18 Oct 2010 21:07:42 +0200
Subject: [PATCH] Add filter that displays part of a String.

---
 .../sone/template/SubstringFilter.java             | 69 ++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 src/main/java/net/pterodactylus/sone/template/SubstringFilter.java

diff --git a/src/main/java/net/pterodactylus/sone/template/SubstringFilter.java b/src/main/java/net/pterodactylus/sone/template/SubstringFilter.java
new file mode 100644
index 0000000..f0075e4
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sone/template/SubstringFilter.java
@@ -0,0 +1,69 @@
+/*
+ * Sone - SubstringFilter.java - Copyright © 2010 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sone.template;
+
+import java.util.Map;
+
+import net.pterodactylus.util.template.DataProvider;
+import net.pterodactylus.util.template.Filter;
+
+/**
+ * {@link Filter} implementation that executes
+ * {@link String#substring(int, int)} on the given data. It has two parameters:
+ * “start” and “length.” “length” is optional and defaults to “the rest of the
+ * string.” “start” starts at {@code 0} and can be negative to denote starting
+ * at the end of the string.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class SubstringFilter implements Filter {
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Object format(DataProvider dataProvider, Object data, Map<String, String> parameters) {
+		String startString = parameters.get("start");
+		String lengthString = parameters.get("length");
+		int start = 0;
+		try {
+			start = Integer.parseInt(startString);
+		} catch (NumberFormatException nfe1) {
+			/* ignore. */
+		}
+		String dataString = String.valueOf(data);
+		int dataLength = dataString.length();
+		if (lengthString == null) {
+			if (start < 0) {
+				return dataString.substring(dataLength + start);
+			}
+			return dataString.substring(start);
+		}
+		int length = Integer.MAX_VALUE;
+		try {
+			length = Integer.parseInt(lengthString);
+		} catch (NumberFormatException nfe1) {
+			/* ignore. */
+		}
+		if (start < 0) {
+			return dataString.substring(dataLength + start, Math.min(dataLength, dataLength + start + length));
+		}
+		return dataString.substring(start, Math.min(dataLength, start + length));
+	}
+
+}
-- 
2.7.4