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.core;
54
55 import freemarker.template;
56
57 /**
58 * An instruction that assigns a literal or reference, to a single-identifier
59 * variable.
60 */
61 final class Assignment extends TemplateElement {
62
63 private String variableName;
64 private Expression value, namespaceExp;
65 private int scope;
66
67 static final int NAMESPACE = 1;
68 static final int LOCAL = 2;
69 static final int GLOBAL = 3;
70
71 /**
72 * @param variableName the variable name to assign to.
73 * @param value the expression to assign.
74 * @param scope the scope of the assignment, one of NAMESPACE, LOCAL, or GLOBAL
75 */
76 Assignment(String variableName,
77 Expression value,
78 int scope)
79 {
80 this.variableName = variableName;
81 this.value = value;
82 this.scope = scope;
83 }
84
85 void setNamespaceExp(Expression namespaceExp) {
86 this.namespaceExp = namespaceExp;
87 }
88
89 void accept(Environment env) throws TemplateException {
90 TemplateModel tm = value.getAsTemplateModel(env);
91 Environment.Namespace namespace = null;
92 if (namespaceExp != null) {
93 boolean oops = false;
94 try {
95 namespace = (Environment.Namespace) namespaceExp.getAsTemplateModel(env);
96 } catch (ClassCastException cce) {
97 oops = true;
98 }
99 if (oops || namespace==null) {
100 throw new InvalidReferenceException(getStartLocation() + "\nInvalid reference to namespace: " + namespaceExp, env);
101 }
102 }
103 if (tm == null) {
104 if (env.isClassicCompatible()) {
105 tm = TemplateScalarModel.EMPTY_STRING;
106 }
107 else {
108 String msg = "Error " + getStartLocation()
109 +"\n" + value + " is undefined."
110 +"\nIt cannot be assigned to " + variableName;
111 throw new InvalidReferenceException(msg, env);
112 }
113 }
114 if (scope == LOCAL) {
115 env.setLocalVariable(variableName, tm);
116 }
117 else {
118 if (namespace == null) {
119 if (scope == GLOBAL) {
120 namespace = env.getGlobalNamespace();
121 }
122 else if (scope == NAMESPACE) {
123 namespace = env.getCurrentNamespace();
124 }
125 }
126 namespace.put(variableName, tm);
127 }
128 }
129
130 public String getCanonicalForm() {
131 StringBuffer buf = new StringBuffer();
132 if (!(parent instanceof AssignmentInstruction)) {
133 if (scope == LOCAL) {
134 buf.append("<#local ");
135 }
136 else if (scope ==GLOBAL) {
137 buf.append("<#global ");
138 }
139 else {
140 buf.append("<#assign ");
141 }
142 }
143 buf.append (variableName);
144 buf.append('=');
145 buf.append(value.getCanonicalForm());
146 if (!(parent instanceof AssignmentInstruction)) {
147 if (namespaceExp != null) {
148 buf.append(" in ");
149 buf.append(namespaceExp.getCanonicalForm());
150 }
151 buf.append(">");
152 }
153 return buf.toString();
154 }
155
156 public String getDescription() {
157 String s ="";
158 if (!(parent instanceof AssignmentInstruction)) {
159 s = "assignment: ";
160 if (scope == LOCAL) {
161 s = "local " + s;
162 }
163 else if (scope == GLOBAL) {
164 s = "global " + s;
165 }
166 }
167 return s + variableName
168 + "="
169 + value;
170 }
171 }
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