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1
52
53 package freemarker.core;
54
55 import freemarker.template.*;
56 import freemarker.ext.beans.BeanModel;
57
58
62 abstract public class Expression extends TemplateObject {
63
64 abstract TemplateModel _getAsTemplateModel(Environment env) throws TemplateException;
65 abstract boolean isLiteral();
66
67
70 TemplateModel constantValue;
71
72
74 void setLocation(Template template, int beginColumn, int beginLine, int endColumn, int endLine)
75 throws
76 ParseException
77 {
78 super.setLocation(template, beginColumn, beginLine, endColumn, endLine);
79 if (isLiteral()) {
80 try {
81 constantValue = _getAsTemplateModel(null);
82 } catch (Exception  e) {
83 }
85 }
86 }
87
88 public final TemplateModel getAsTemplateModel(Environment env) throws TemplateException {
89 return constantValue != null ? constantValue : _getAsTemplateModel(env);
90 }
91
92 String getStringValue(Environment env) throws TemplateException {
93 return getStringValue(getAsTemplateModel(env), this, env);
94 }
95
96 static String getStringValue(TemplateModel referentModel, Expression exp, Environment env)
97 throws
98 TemplateException
99 {
100 if (referentModel instanceof TemplateNumberModel) {
101 return env.formatNumber(EvaluationUtil.getNumber((TemplateNumberModel) referentModel, exp, env));
102 }
103 if (referentModel instanceof TemplateDateModel) {
104 TemplateDateModel dm = (TemplateDateModel) referentModel;
105 return env.formatDate(EvaluationUtil.getDate(dm, exp, env), dm.getDateType());
106 }
107 if (referentModel instanceof TemplateScalarModel) {
108 return EvaluationUtil.getString((TemplateScalarModel) referentModel, exp, env);
109 }
110 if(env.isClassicCompatible()) {
111 if (referentModel instanceof TemplateBooleanModel) {
112 return ((TemplateBooleanModel)referentModel).getAsBoolean() ? "true" : "";
113 }
114 if (referentModel == null) {
115 return "";
116 }
117 }
118 assertNonNull(referentModel, exp, env);
119
120 String msg = "Error " + exp.getStartLocation()
121 +"\nExpecting a string, "
122 + (env.isClassicCompatible() ? "boolean, " : "" )
123 + "date or number here, Expression " + exp
124 + " is instead a "
125 + referentModel.getClass().getName();
126 throw new NonStringException(msg, env);
127 }
128
129 Expression deepClone(String name, Expression subst) {
130 Expression clone = _deepClone(name, subst);
131 clone.copyLocationFrom(this);
132 return clone;
133 }
134
135 abstract Expression _deepClone(String name, Expression subst);
136
137 boolean isTrue(Environment env) throws TemplateException {
138 TemplateModel referent = getAsTemplateModel(env);
139 if (referent instanceof TemplateBooleanModel) {
140 return ((TemplateBooleanModel) referent).getAsBoolean();
141 }
142 if (env.isClassicCompatible()) {
143 return referent != null && !isEmpty(referent);
144 }
145 assertNonNull(referent, this, env);
146 String msg = "Error " + getStartLocation()
147 + "\nExpecting a boolean (true/false) expression here"
148 + "\nExpression " + this + " does not evaluate to true/false "
149 + "\nit is an instance of " + referent.getClass().getName();
150 throw new NonBooleanException(msg, env);
151 }
152
153
154 static boolean isEmpty(TemplateModel model) throws TemplateModelException
155 {
156 if (model instanceof BeanModel) {
157 return ((BeanModel) model).isEmpty();
158 } else if (model instanceof TemplateSequenceModel) {
159 return ((TemplateSequenceModel) model).size() == 0;
160 } else if (model instanceof TemplateScalarModel) {
161 String s = ((TemplateScalarModel) model).getAsString();
162 return (s == null || s.length() == 0);
163 } else if (model instanceof TemplateCollectionModel) {
164 return !((TemplateCollectionModel) model).iterator().hasNext();
165 } else if (model instanceof TemplateHashModel) {
166 return ((TemplateHashModel) model).isEmpty();
167 } else {
168 return true;
169 }
170 }
171 }
172 |
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