1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2 <html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> 3 <title>TinyXml: TinyXML Tutorial</title> 4 <link href="doxygen.css" rel="stylesheet" type="text/css"> 5 </head><body> 6 <!-- Generated by Doxygen 1.4.4 --> 7 <div class="qindex"><a class="qindex" href="index.html">Main Page</a> | <a class="qindex" href="hierarchy.html">Class Hierarchy</a> | <a class="qindex" href="annotated.html">Class List</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="functions.html">Class Members</a></div> 8 <div class="nav"> 9 <a class="el" href="index.html">index</a></div> 10 <h1><a class="anchor" name="tutorial0">TinyXML Tutorial</a></h1><h1>Tutorial Preliminary </h1> 11 <p> 12 These pages contains a bunch of examples of using TinyXml.<p> 13 Each demo is written in a standalone function. If you want to try the code, all you need to do is copy/paste the code into a file, then have a main to call it.<p> 14 So if the example has a function:<p> 15 <div class="fragment"><pre class="fragment"> void write_simple_doc() 16 { 17 ... 18 } 19 </pre></div><p> 20 then the *complete* program you need to try it is:<p> 21 <div class="fragment"><pre class="fragment"> #include "stdafx.h" // <-- you MIGHT need this 22 #include "tinyxml.h" // <-- you definitely need this ;) 23 24 void write_simple_doc() 25 { 26 ... 27 } 28 29 void main( void ) 30 { 31 write_simple_doc(); 32 } 33 </pre></div><p> 34 Two example XML datasets/files will be used. The first looks like this:<p> 35 <div class="fragment"><pre class="fragment"> <?xml version="1.0" ?> 36 <Hello>World</Hello> 37 </pre></div><p> 38 The other:<p> 39 <div class="fragment"><pre class="fragment"> <?xml version="1.0" ?> 40 <poetry> 41 <verse> 42 Alas 43 Great Whatever 44 Alas (again) 45 </verse> 46 </poetry> 47 </pre></div><p> 48 <h1>Getting Started </h1> 49 <p> 50 <h2>Load XML from a file </h2> 51 <p> 52 Loading a file is as simple as:<p> 53 <div class="fragment"><pre class="fragment"> void load_file( ) 54 { 55 TiXmlDocument doc( "demo.xml" ); 56 bool loadOkay = doc.LoadFile(); 57 58 if ( loadOkay ) 59 { 60 // Your document is loaded - do what you like 61 // with it. 62 // 63 // Here we'll dump the structure to STDOUT, 64 // just for example 65 dump_to_stdout( &doc ); 66 } 67 else 68 { 69 // load failed 70 } 71 } 72 </pre></div><p> 73 The ``dump_to_stdout`` function is defined in the section `Dump structure of a Document to STDOUT` below. If you run this program with this XML:<p> 74 <div class="fragment"><pre class="fragment"> <?xml version="1.0" ?> 75 <Hello>World</Hello> 76 </pre></div><p> 77 You'll see this:<p> 78 <div class="fragment"><pre class="fragment"> DOCUMENT 79 + DECLARATION 80 + ELEMENT Hello 81 + TEXT[World] 82 </pre></div><p> 83 <h2>Building Documents Programatically </h2> 84 <p> 85 Example:<p> 86 <div class="fragment"><pre class="fragment"> void write_simple_doc( ) 87 { 88 // Make xml: <?xml ..><Hello>World</Hello> 89 TiXmlDocument doc; 90 TiXmlDeclaration * decl = new TiXmlDeclaration( "1.0", "", "" ); 91 TiXmlElement * element = new TiXmlElement( "Hello" ); 92 TiXmlText * text = new TiXmlText( "World" ); 93 element->LinkEndChild( text ); 94 doc.LinkEndChild( decl ); 95 doc.LinkEndChild( element ); 96 97 dump_to_stdout( &doc ); 98 doc.SaveFile( "madeByHand.xml" ); 99 } 100 </pre></div><p> 101 Alternatively:<p> 102 <div class="fragment"><pre class="fragment"> void write_simple_doc2( ) 103 { 104 // same as write_simple_doc1 but add each node 105 // as early as possible into the tree. 106 107 TiXmlDocument doc; 108 TiXmlDeclaration * decl = new TiXmlDeclaration( "1.0", "", "" ); 109 doc.LinkEndChild( decl ); 110 111 TiXmlElement * element = new TiXmlElement( "Hello" ); 112 doc.LinkEndChild( element ); 113 114 TiXmlText * text = new TiXmlText( "World" ); 115 element->LinkEndChild( text ); 116 117 dump_to_stdout( &doc ); 118 doc.SaveFile( "madeByHand2.xml" ); 119 } 120 </pre></div><p> 121 Both of these produce the same XML, namely:<p> 122 <div class="fragment"><pre class="fragment"> <?xml version="1.0" ?> 123 <Hello>World</Hello> 124 </pre></div><p> 125 Or in structure form:<p> 126 <div class="fragment"><pre class="fragment"> DOCUMENT 127 + DECLARATION 128 + ELEMENT Hello 129 + TEXT[World] 130 </pre></div><p> 131 <h2>Saving Documents to File </h2> 132 <p> 133 This function:<p> 134 <div class="fragment"><pre class="fragment"> void write_simple_doc3( ) 135 { 136 // This example courtesy of polocolege 137 138 TiXmlDocument doc; 139 TiXmlDeclaration * decl = new TiXmlDeclaration( "1.0", "", "" ); 140 doc.LinkEndChild( decl ); 141 142 TiXmlElement * element = new TiXmlElement( "Hello" ); 143 doc.LinkEndChild( element ); 144 145 TiXmlText * text = new TiXmlText( "Opening a new salutation" ); 146 element->LinkEndChild( text ); 147 148 TiXmlElement * element2 = new TiXmlElement( "Greeting" ); 149 element->LinkEndChild( element2 ); 150 151 TiXmlText * text2 = new TiXmlText( "How are you?" ); 152 element2->LinkEndChild( text2 ); 153 154 TiXmlElement * element3 = new TiXmlElement( "Language" ); 155 element2->LinkEndChild( element3 ); 156 157 TiXmlText * text3 = new TiXmlText( "English" ); 158 element3->LinkEndChild( text3 ); 159 160 TiXmlElement * element4 = new TiXmlElement( "Exclamation" ); 161 element->LinkEndChild( element4 ); 162 163 TiXmlText * text4 = new TiXmlText( "You have children!" ); 164 element4->LinkEndChild( text4 ); 165 166 dump_to_stdout( &doc ); 167 doc.SaveFile( "madeByHand3.xml" ); 168 } 169 </pre></div><p> 170 Produces this structure:<p> 171 <div class="fragment"><pre class="fragment"> Document 172 + Declaration 173 + Element "Hello" 174 + Text: [Opening a new salutation] 175 + Element "Greeting" 176 + Text: [How are you?] 177 + Element "Language" 178 + Text: [English] 179 + Element "Exclamation" 180 + Text: [You have children!] 181 </pre></div><p> 182 The file ``madeByHand3.xml`` looks exactly like this (including indents):<p> 183 <div class="fragment"><pre class="fragment"> <?xml version="1.0" ?> 184 <Hello>Opening a new salutation 185 <Greeting>How are you? 186 <Language>English</Language> 187 </Greeting> 188 <Exclamation>You have children!</Exclamation> 189 </Hello> 190 </pre></div><p> 191 I was surprised that TinyXml, by default, writes the XML in what other APIs call a "pretty" format - it modifies the whitespace of text of elements that contain other nodes so that writing the tree includes an indication of nesting level.<p> 192 I haven't looked yet to see if there is a way to turn off indenting when writing a file - its bound to be easy.<p> 193 [Lee: It's easy in STL mode, just use cout << myDoc. Non-STL mode is always in "pretty" format. Adding a switch would be a nice feature and has been requested.]<p> 194 <h1>Iterating Over Documents </h1> 195 <p> 196 <h2>Dump structure of a Document to STDOUT </h2> 197 <p> 198 Often when you're starting its helpful and reassuring to know that you're document got loaded as you expect it to.<p> 199 Below I've defined a function to walk a document and write contents to STDOUT:<p> 200 <div class="fragment"><pre class="fragment"> // a utility function defining a very simple method to indent a line of text 201 const char * getIndent( unsigned int numIndents ) 202 { 203 static const char * pINDENT = " + "; 204 static const unsigned int LENGTH = strlen( pINDENT ); 205 206 if ( numIndents > LENGTH ) numIndents = LENGTH; 207 208 return &pINDENT[ LENGTH-numIndents ]; 209 } 210 211 void dump_to_stdout( TiXmlNode * pParent, unsigned int indent = 0 ) 212 { 213 if ( !pParent ) return; 214 215 TiXmlText *pText; 216 int t = pParent->Type(); 217 printf( "%s", getIndent( indent)); 218 219 switch ( t ) 220 { 221 case TiXmlNode::DOCUMENT: 222 printf( "Document" ); 223 break; 224 225 case TiXmlNode::ELEMENT: 226 printf( "Element \"%s\"", pParent->Value() ); 227 break; 228 229 case TiXmlNode::COMMENT: 230 printf( "Comment: \"%s\"", pParent->Value()); 231 break; 232 233 case TiXmlNode::UNKNOWN: 234 printf( "Unknown" ); 235 break; 236 237 case TiXmlNode::TEXT: 238 pText = pParent->ToText(); 239 printf( "Text: [%s]", pText->Value() ); 240 break; 241 242 case TiXmlNode::DECLARATION: 243 printf( "Declaration" ); 244 break; 245 default: 246 break; 247 } 248 printf( "\n" ); 249 250 TiXmlNode * pChild; 251 252 for ( pChild = pParent->FirstChild(); pChild != 0; pChild = pChild->NextSibling()) 253 { 254 dump_to_stdout( pChild, indent+2 ); 255 } 256 } 257 </pre></div><p> 258 To load a file and dump its structure:<p> 259 <div class="fragment"><pre class="fragment"> void load_and_display( ) 260 { 261 // important for the poetry demo, but you may not need this 262 // in your own projects 263 TiXmlBase::SetCondenseWhiteSpace( false ); 264 265 TiXmlDocument doc( "demo.xml" ); 266 bool loadOkay = doc.LoadFile(); 267 268 if ( loadOkay ) 269 { 270 dump_to_stdout( &doc ); 271 } 272 else 273 { 274 printf( "Something went wrong\n" ); 275 } 276 } 277 </pre></div><p> 278 If you run this with the first XML file you'll see this on STDOUT:<p> 279 <div class="fragment"><pre class="fragment"> DOCUMENT 280 + DECLARATION 281 + ELEMENT Hello 282 + TEXT[World] 283 </pre></div><p> 284 and on the second XML file:<p> 285 <div class="fragment"><pre class="fragment"> DOCUMENT 286 + DECLARATION 287 + ELEMENT poetry 288 + COMMENT: my great work of art 289 + ELEMENT verse 290 + TEXT[ 291 Alas 292 Great Whatever 293 Alas (again) 294 ] 295 </pre></div><p> 296 Note that if you call dump_to_stdout like this:<p> 297 <div class="fragment"><pre class="fragment"> dump_to_stdout( doc.RootElement()); 298 </pre></div><p> 299 You'll see this instead:<p> 300 <div class="fragment"><pre class="fragment"> ELEMENT Hello 301 + TEXT[World] 302 </pre></div><p> 303 and:<p> 304 <div class="fragment"><pre class="fragment"> ELEMENT poetry 305 + COMMENT: my great work of art 306 + ELEMENT verse 307 + TEXT[ 308 Alas 309 Great Whatever 310 Alas (again) 311 ] 312 </pre></div><p> 313 <em> Authors and Changes <ul> 314 <li> 315 Written by Ellers, April 2005 </li> 316 <li> 317 Minor edits and integration into doc system, Lee Thomason September 2005 </li> 318 </ul> 319 </em> <hr size="1"><address style="align: right;"><small>Generated on Sat Oct 8 14:15:30 2005 for TinyXml by 320 <a href="http://www.doxygen.org/index.html"> 321 <img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.4 </small></address> 322 </body> 323 </html> 324
