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1 /*
2 * Copyright (c) 2003 The Visigoth Software Society. All rights
3 * reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. The end-user documentation included with the redistribution, if
18 * any, must include the following acknowledgement:
19 * "This product includes software developed by the
20 * Visigoth Software Society (http://www.visigoths.org/)."
21 * Alternately, this acknowledgement may appear in the software itself,
22 * if and wherever such third-party acknowledgements normally appear.
23 *
24 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
25 * project contributors may be used to endorse or promote products derived
26 * from this software without prior written permission. For written
27 * permission, please contact visigoths@visigoths.org.
28 *
29 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
30 * nor may "FreeMarker" or "Visigoth" appear in their names
31 * without prior written permission of the Visigoth Software Society.
32 *
33 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36 * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
37 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of the Visigoth Software Society. For more
49 * information on the Visigoth Software Society, please see
50 * http://www.visigoths.org/
51 */
52
53 package freemarker.template.utility;
54
55 import freemarker.template;
56 import freemarker.core.Environment;
57 import java.io;
58 import java.util.Map;
59
60 /**
61 * A transform that captures the output of a block of FTL code and stores that in a variable.
62 *
63 * <p>As this transform is initially present in the shared variable set, you can always
64 * access it from the templates:</p>
65 *
66 * <pre>
67 * <@capture_output var="captured">
68 * ...
69 * </@capture_output>
70 * </pre>
71 *
72 * <p>And later in the template you can use the captured output:</p>
73 *
74 * ${captured}
75 *
76 * <p>This transform requires one of three parameters: <code>var</code>, <code>local</code>, or <code>global</code>.
77 * Each of them specifies the name of the variable that stores the captured output, but the first creates a
78 * variable in a name-space (as <#assign>), the second creates a macro-local variable (as <#local>),
79 * and the last creates a global variable (as <#global>).
80 * </p>
81 * <p>In the case of an assignment within a namespace, there is an optional parameter
82 * <code>namespace</code> that indicates in which namespace to do the assignment.
83 * if this is omitted, the current namespace is used, and this will be, by far, the most
84 * common usage pattern.</p>
85 *
86 * @deprecated Use block-assignments instead, as <code><assign x>...</assign></code>.
87 *
88 * @version $Id: CaptureOutput.java,v 1.31 2004/01/06 17:06:43 szegedia Exp $
89 */
90 public class CaptureOutput implements TemplateTransformModel {
91
92 public Writer getWriter(final Writer out, final Map args) throws TemplateModelException {
93 String errmsg = "Must specify the name of the variable in "
94 + "which to capture the output with the 'var' or 'local' or 'global' parameter.";
95 if (args == null) throw new TemplateModelException(errmsg);
96
97 boolean local = false, global=false;
98 final TemplateModel nsModel = (TemplateModel) args.get("namespace");
99 Object varNameModel = args.get("var");
100 if (varNameModel == null) {
101 varNameModel = args.get("local");
102 if (varNameModel == null) {
103 varNameModel = args.get("global");
104 global = true;
105 } else {
106 local = true;
107 }
108 if (varNameModel == null) {
109 throw new TemplateModelException(errmsg);
110 }
111 }
112 if (args.size()==2) {
113 if (nsModel == null) {
114 throw new TemplateModelException("Second parameter can only be namespace");
115 }
116 if (local) {
117 throw new TemplateModelException("Cannot specify namespace for a local assignment");
118 }
119 if (global) {
120 throw new TemplateModelException("Cannot specify namespace for a global assignment");
121 }
122 if (!(nsModel instanceof Environment.Namespace)) {
123 throw new TemplateModelException("namespace parameter does not specify a namespace. It is a " + nsModel.getClass().getName());
124 }
125 }
126 else if (args.size() != 1) throw new TemplateModelException(
127 "Bad parameters. Use only one of 'var' or 'local' or 'global' parameters.");
128
129 if(!(varNameModel instanceof TemplateScalarModel)) {
130 throw new TemplateModelException("'var' or 'local' or 'global' parameter doesn't evaluate to a string");
131 }
132 final String varName = ((TemplateScalarModel) varNameModel).getAsString();
133 if(varName == null) {
134 throw new TemplateModelException("'var' or 'local' or 'global' parameter evaluates to null string");
135 }
136
137 final StringBuffer buf = new StringBuffer();
138 final Environment env = Environment.getCurrentEnvironment();
139 final boolean localVar = local;
140 final boolean globalVar = global;
141
142 return new Writer() {
143
144 public void write(char cbuf[], int off, int len) {
145 buf.append(cbuf, off, len);
146 }
147
148 public void flush() throws IOException {
149 out.flush();
150 }
151
152 public void close() throws IOException {
153 SimpleScalar result = new SimpleScalar(buf.toString());
154 try {
155 if (localVar) {
156 env.setLocalVariable(varName, result);
157 } else if (globalVar) {
158 env.setGlobalVariable(varName, result);
159 }
160 else {
161 if (nsModel == null) {
162 env.setVariable(varName, result);
163 } else {
164 ((Environment.Namespace) nsModel).put(varName, result);
165 }
166 }
167 } catch (java.lang.IllegalStateException ise) { // if somebody uses 'local' outside a macro
168 throw new IOException("Could not set variable " + varName + ": " + ise.getMessage());
169 }
170 }
171 };
172 }
173 }