ViewUtil


1   /*
2    * Copyright (C) 2003  Christian Cryder [christianc@granitepeaks.com]
3    *
4    * This library is free software; you can redistribute it and/or
5    * modify it under the terms of the GNU Lesser General Public
6    * License as published by the Free Software Foundation; either
7    * version 2.1 of the License, or (at your option) any later version.
8    *
9    * This library is distributed in the hope that it will be useful,
10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   * Lesser General Public License for more details.
13   *
14   * You should have received a copy of the GNU Lesser General Public
15   * License along with this library; if not, write to the Free Software
16   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17   *
18   * $Id: ViewUtil.java,v 1.8 2004/02/01 05:16:28 christianc Exp $
19   */
20  package org.enhydra.barracuda.core.view;
21  
22  import java.util.*;
23  import javax.servlet.*;
24  import javax.servlet.http.*;
25  
26  import org.enhydra.barracuda.core.helper.servlet.*;
27  
28  /**
29   * <p>This class provides utility functions for determining the ViewCapabilities.
30   * 
31   * <p>Note that currently only the HTML related logic is fully implemented. If
32   * you need support for specific versions of WML, CHTML, etc, you may have to
33   * add some code here to examine the appropriate headers and map it to the 
34   * proper types. If you have expertise working with these other flavors of 
35   * markup and would like to help flesh out support for these languages, email
36   * the list and we'll be glad to give you pointers...
37   */
38  public class ViewUtil {
39  
40      //base data types
41      private static int HTML = 0;
42      private static int CHTML = 1;
43      private static int XML = 2;
44      private static int VXML = 3;
45      private static int WML = 4;
46      private static int XHTML_BASIC = 5;
47      private static int XHTML_STANDARD = 6;
48  
49      /**
50       * Determine the format type by looking at the Accept header in 
51       * the request
52       *
53       * @param req an HttpServletRequest object
54       * @return the appropriate client type (defaults to FormatType.UNKNOWN_FORMAT
55       *      if we are unable to make a positive match)
56       */
57      public static FormatType getFormatType(HttpServletRequest req) {
58          FormatType ft = FormatType.UNKNOWN_FORMAT;
59          int baseType = getBaseType(req);
60  
61          //figure out what we're dealing with
62          //...HTML
63          if (baseType==HTML) {
64              ft = FormatType.HTML_4_0;
65          //...CHTML
66          } else if (baseType==CHTML) {
67              ft = FormatType.CHTML_1_0;
68          //...XML
69          } else if (baseType==XML) {
70              ft = FormatType.XML_1_0;
71          //...VXML
72          } else if (baseType==VXML) {
73              ft = FormatType.VXML_1_0;
74          //...WML
75          } else if (baseType==WML) {
76              ft = FormatType.WML_1_0;
77          //...XHTML_BASIC
78          } else if (baseType==XHTML_BASIC) {
79              ft = FormatType.XHTML_BASIC_1_0;
80          //...XHTML_STANDARD
81          } else if (baseType==XHTML_STANDARD) {
82              ft = FormatType.XHTML_STANDARD_1_0;
83          }
84          
85          return ft;
86      }
87  
88      /**
89       * Determine the what type of scripting is supported by figuring 
90       * out what kind of browser we're dealing with. Note that this method
91       * does NOT determine whether or not the browser actually has scripting
92       * enabled.
93       *
94       * @param req an HttpServletRequest object
95       * @return the appropriate client type (defaults to ScriptingType.NONE
96       *      if we are unable to make a positive match)
97       */
98      public static ScriptingType getScriptingType(HttpServletRequest req) {
99          ScriptingType st = ScriptingType.NONE;
100         if (req!=null) {
101         
102             //csc_102201.1
103             //first and foremost see if the request includes a scripting tag,
104             //which would be a direct indication from the client of what it
105             //supports. If it comes back false, we can immediately return;
106             //otherwise, we still try to figure out the specific level of support
107             //by looking at the client type (except we can now safely default to
108             //Javascript 1.0)
109             Boolean   enabled = ScriptDetector.scriptingEnabled(req);
110             if (enabled!=null) {
111                 if (enabled.booleanValue()==false) return ScriptingType.NONE;
112                 else st = ScriptingType.JAVASCRIPT_1_0;
113             }
114         
115             //first get the client type
116             ClientType ct = getClientType(req);
117             
118             //now map accordingly (note that we are not actually determining
119             //whether or not the scripting is enabled). I got these mappings from
120             //http://www.digitalroom.net/index2.html
121             //http://www.javascripter.net/faq/javascr3.htm
122             if (ct instanceof ClientType.HtmlBrowser) {
123                 if (ct instanceof ClientType.IE5x) st = ScriptingType.JAVASCRIPT_1_3;
124                 else if (ct instanceof ClientType.IE4x) st = ScriptingType.JAVASCRIPT_1_2;  //note: the first link asserts (above) IE4x actually supports 1.3
125                 else if (ct instanceof ClientType.IE3x) st = ScriptingType.JAVASCRIPT_1_0;
126                 else if (ct instanceof ClientType.NN6x) st = ScriptingType.JAVASCRIPT_1_5;
127                 else if (ct instanceof ClientType.NN4x) st = ScriptingType.JAVASCRIPT_1_3;
128                 else if (ct instanceof ClientType.NN3x) st = ScriptingType.JAVASCRIPT_1_1;  //by 4x we're assuming NN 4.5 or higher
129                 else if (ct instanceof ClientType.Opera4x) st = ScriptingType.JAVASCRIPT_1_3;
130                 else if (ct instanceof ClientType.Html32Browser) st = ScriptingType.JAVASCRIPT_1_0;
131             } else if (ct instanceof ClientType.WmlBrowser) {
132                 st = ScriptingType.WMLSCRIPT_1x;
133             }
134         }
135         return st;
136     }
137 
138     /**
139      * Determine the client type by looking at the User-Agent header in 
140      * the request
141      *
142      * @param req an HttpServletRequest object
143      * @return the appropriate client type (defaults to ClientType.UNKNOWN_BROWSER
144      *      if we are unable to make a positive match)
145      */
146     public static ClientType getClientType(HttpServletRequest req) {
147         ClientType ct = ClientType.UNKNOWN_BROWSER;
148         chk: if (req!=null) {
149             //get the user agent string
150             String   uas = req.getHeader("User-Agent");
151             if (uas==null) uas = req.getHeader("user-agent");
152             if (uas==null) break chk;
153             uas = uas.toLowerCase();
154 
155             int baseType = getBaseType(req);
156 
157             //figure out what we're dealing with
158             //...HTML
159             if (baseType==HTML) {
160                 //these here are going to cover the most common situations
161                 //...Opera (we check for opera first since it masquerades as both IE and NN)
162                 if (uas.indexOf("opera")!=-1) {
163                     if (uas.indexOf("opera/5")!=-1) ct = ClientType.OPERA_5x;
164                     else if (uas.indexOf("opera/4")!=-1) ct = ClientType.OPERA_4x;
165                     else if (uas.indexOf("opera 5")!=-1) ct = ClientType.OPERA_5x;
166                     else if (uas.indexOf("opera 4")!=-1) ct = ClientType.OPERA_4x;
167                     else if (uas.indexOf("opera/2")!=-1) ct = ClientType.HTML_BROWSER;
168                     else if (uas.indexOf("opera 2")!=-1) ct = ClientType.HTML_BROWSER;
169                     else ct = ClientType.HTML_3_2_BROWSER;
170                 //...IE (next we check for IE, since it also looks like NN)
171                 } else if (uas.indexOf("msie ")!=-1) {
172                     if (uas.indexOf("msie 6")!=-1) ct = ClientType.IE_6x;
173                     else if (uas.indexOf("msie 5")!=-1) ct = ClientType.IE_5x;
174                     else if (uas.indexOf("msie 4")!=-1) ct = ClientType.IE_4x;
175                     else if (uas.indexOf("msie 3")!=-1) ct = ClientType.IE_3x;
176                     else if (uas.indexOf("msie 2")!=-1) ct = ClientType.HTML_BROWSER;
177                     else ct = ClientType.HTML_3_2_BROWSER;
178                 //...NN  (it its none of the above, its probably NN)
179                 } else if (uas.indexOf("mozilla")!=-1) {
180                     if (uas.indexOf("netscape6")!=-1) ct = ClientType.NN_6x;
181                     else if (uas.indexOf("gecko")!=-1) ct = ClientType.NN_6x;
182                     else if (uas.indexOf("mozilla/5")!=-1) ct = ClientType.HTML_4_0_BROWSER;
183                     else if (uas.indexOf("mozilla/4")!=-1) ct = ClientType.NN_4x;
184                     else if (uas.indexOf("mozilla/3")!=-1) ct = ClientType.NN_3x;
185                     else if (uas.indexOf("mozilla 5")!=-1) ct = ClientType.HTML_4_0_BROWSER;
186                     else if (uas.indexOf("mozilla 4")!=-1) ct = ClientType.NN_4x;
187                     else if (uas.indexOf("mozilla 3")!=-1) ct = ClientType.NN_3x;
188                     else ct = ClientType.HTML_BROWSER;
189                 }
190                 if (ct!=ClientType.UNKNOWN_BROWSER) break chk;
191             
192             
193                 //if we're still looking at an unknown browser, now we can get 
194                 //more specific (we do these checks down here for performance 
195                 //purposes...we only want to check these when we have to)
196                 if (uas.indexOf("lynx")!=-1) ct = ClientType.HTML_3_2_BROWSER;
197                 else if (uas.indexOf("konqueror")!=-1) ct = ClientType.HTML_BROWSER;
198                 else if (uas.indexOf("mozilla")!=-1) ct = ClientType.HTML_BROWSER;
199             //...CHTML
200             } else if (baseType==CHTML) {
201                 //TODO: we still need better granularity for this
202                 ct = ClientType.CHTML_BROWSER;
203             //...XML
204             } else if (baseType==XML) {
205                 //TODO: we still need better granularity for this
206                 ct = ClientType.XML_BROWSER;
207             //...VXML
208             } else if (baseType==VXML) {
209                 //TODO: we still need better granularity for this
210                 ct = ClientType.VXML_BROWSER;
211             //...WML
212             } else if (baseType==WML) {
213                 //TODO: we still need better granularity for this. A good place
214                 //to look for a whole slew of sample headers is
215                 //http://amaro.g-art.nl/useragent/
216                 ct = ClientType.WML_BROWSER;
217             //...XHTML_BASIC
218             } else if (baseType==XHTML_BASIC) {
219                 //TODO: we still need better granularity for this
220                 ct = ClientType.XHTML_BROWSER;
221             //...XHTML_STANDARD
222             } else if (baseType==XHTML_STANDARD) {
223                 //TODO: we still need better granularity for this
224                 ct = ClientType.XHTML_BROWSER;
225             }
226         }
227         return ct;
228     }
229 
230     //look in the accept header to determine the basic content type
231     private static int getBaseType(HttpServletRequest req) {
232         int baseType = HTML;    //default
233         chk: if (req!=null) {
234             //get the accept string
235             String   acc = req.getHeader("Accept");
236             if (acc==null) acc = req.getHeader("accept");
237             if (acc==null) break chk;
238             acc = acc.toLowerCase();
239 
240             //now figure out what we're dealing with
241             if (acc.indexOf("text/html")!=-1) baseType = HTML;
242             else if (acc.indexOf("text/vnd.wap.wml")!=-1) baseType = WML;
243             else if (acc.indexOf("text/chtml")!=-1) baseType = CHTML;
244             else if (acc.indexOf("text/xml")!=-1) baseType = XML;
245             //TODO: identify VXML
246             //TODO: identify XHTML_BASIC
247             //TODO: identify XHTML_STANDARD
248        }
249         return baseType;
250     }
251 }
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