1 /*
2 * Copyright 2004-2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springmodules.validation.valang.javascript.taglib;
18
19 import java.io.IOException;
20 import java.io.Reader;
21 import java.io.Writer;
22
23 import javax.servlet.ServletException;
24 import javax.servlet.jsp.JspException;
25 import javax.servlet.jsp.JspWriter;
26
27 import org.springframework.util.Assert;
28 import org.springframework.web.servlet.tags.RequestContextAwareTag;
29 import org.springmodules.validation.valang.javascript.ValangJavaScriptTranslator;
30
31 /**
32 * Generates the JavaScript codebase that is necessary for the use of the
33 * JavaScript validation produced by {@link ValangValidateTag}.
34 * <p/>
35 * <p>The generated codebase is an exact copy of the code from the file
36 * "valang_codebase.js" located in
37 * org.springmodules.validation.valang.javascript. You can therefor avoid having to
38 * use this tag by simply placing this file on your web server and linking
39 * to it using a the following HTML:
40 * <pre>
41 * <script type="text/javascript" src="/somepath/valang_codebase.js"></script>
42 * </pre>
43 * <p/>
44 * <p>When using this tag or the HTML above you must make sure that the
45 * codebase is included before any {@link ValangValidateTag}s in you JSP file.
46 *
47 * @author Oliver Hutchison
48 */
49 public class ValangCodebaseTag extends RequestContextAwareTag {
50
51 private final static String DEFAULT_GLOBAL_ERRORS_ID = "global_errors";
52
53 private final static String DEFAULT_FIELD_ERROR_ID_SUFFIX = "_error";
54
55 private boolean includeScriptTags;
56
57 private String globalErrorsId = DEFAULT_GLOBAL_ERRORS_ID;
58
59 private String fieldErrorsIdSuffix = DEFAULT_FIELD_ERROR_ID_SUFFIX;
60
61 /**
62 * Sets whether or not the generated code should be wrapped in HTML
63 * <script> tags. This is useful if you wont to include the
64 * codebase directly in a HTML page.
65 */
66 public void setIncludeScriptTags(String includeScriptTags) {
67 this.includeScriptTags = "true".equalsIgnoreCase(includeScriptTags);
68 }
69
70 /**
71 * Sets the id of the element that will hold the global error. If not set, this tag will look for
72 * an element with id "global_errors".
73 *
74 * @param globalErrorsId The id of the element that should hold the global errors.
75 */
76 public void setGlobalErrorsId(String globalErrorsId) {
77 this.globalErrorsId = globalErrorsId;
78 }
79
80 /**
81 * Sets the id suffix of the element that should hold the error of a specific field. For example, if the
82 * validated field is "firstName" and the suffix is set to "_err" then this tag will put the validation
83 * errors for the firstName field in an element with id "firstName_err". If this suffix is not set, it is set
84 * by default to "_error".
85 *
86 * @param fieldErrorsIdSuffix The id suffix of the element that should hold the error of a specific field.
87 */
88 public void setFieldErrorsIdSuffix(String fieldErrorsIdSuffix) {
89 this.fieldErrorsIdSuffix = fieldErrorsIdSuffix;
90 }
91
92 protected int doStartTagInternal() throws ServletException, JspException {
93 return SKIP_BODY;
94 }
95
96 public int doEndTag() throws JspException {
97 try {
98 JspWriter out = pageContext.getOut();
99 if (includeScriptTags) {
100 out.write("<script type=\"text/javascript\">\n");
101 }
102 out.write("var globalErrorsId = '" + globalErrorsId + "';\n");
103 out.write("var fieldErrorIdSuffix = '" + fieldErrorsIdSuffix + "';\n");
104 copy(ValangJavaScriptTranslator.getCodebaseReader(), out);
105 if (includeScriptTags) {
106 out.write("\n</script>");
107 }
108 return EVAL_PAGE;
109 }
110 catch (IOException e) {
111 throw new JspException("Could not write validation codebase", e);
112 }
113 }
114
115 /**
116 * Copies the chars from in to out and then closes in but
117 * leaves out open.
118 */
119 private void copy(Reader in, Writer out) throws IOException {
120 Assert.notNull(in, "No Reader specified");
121 Assert.notNull(out, "No Writer specified");
122 try {
123 char[] buffer = new char[1024];
124 int bytesRead;
125 while ((bytesRead = in.read(buffer)) != -1) {
126 out.write(buffer, 0, bytesRead);
127 }
128 out.flush();
129 }
130 finally {
131 try {
132 in.close();
133 }
134 catch (IOException ex) {
135 logger.warn("Could not close Reader", ex);
136 }
137 }
138 }
139
140 public void doFinally() {
141 super.doFinally();
142 includeScriptTags = false;
143 }
144 }