3 require_once($CFG->libdir
.'/lexer.php');
5 // Constants for the various types of tokens
7 define("TOKEN_USER","0");
8 define("TOKEN_META","1");
9 define("TOKEN_EXACT","2");
10 define("TOKEN_NEGATE","3");
11 define("TOKEN_STRING","4");
12 define("TOKEN_USERID","5");
13 define("TOKEN_DATEFROM","6");
14 define("TOKEN_DATETO","7");
15 define("TOKEN_INSTANCE","8");
17 // Class to hold token/value pairs after they're parsed.
22 function search_token($type,$value){
24 $this->value
= $this->sanitize($value);
28 // Try to clean up user input to avoid potential security issues.
29 // Need to think about this some more.
31 function sanitize($userstring){
32 return htmlspecialchars(addslashes($userstring));
44 // This class does the heavy lifting of lexing the search string into tokens.
45 // Using a full-blown lexer is probably overkill for this application, but
46 // might be useful for other tasks.
48 class search_lexer
extends Lexer
{
50 function search_lexer(&$parser){
52 // Call parent constructor.
53 $this->Lexer($parser);
55 //Set up the state machine and pattern matches for transitions.
57 // Patterns to handle strings of the form datefrom:foo
59 // If we see the string datefrom: while in the base accept state, start
60 // parsing a username and go to the indatefrom state.
61 $this->addEntryPattern("datefrom:\S+","accept","indatefrom");
63 // Snarf everything into the username until we see whitespace, then exit
64 // back to the base accept state.
65 $this->addExitPattern("\s","indatefrom");
68 // Patterns to handle strings of the form dateto:foo
70 // If we see the string dateto: while in the base accept state, start
71 // parsing a username and go to the indateto state.
72 $this->addEntryPattern("dateto:\S+","accept","indateto");
74 // Snarf everything into the username until we see whitespace, then exit
75 // back to the base accept state.
76 $this->addExitPattern("\s","indateto");
79 // Patterns to handle strings of the form instance:foo
81 // If we see the string instance: while in the base accept state, start
82 // parsing for instance number and go to the ininstance state.
83 $this->addEntryPattern("instance:\S+","accept","ininstance");
85 // Snarf everything into the username until we see whitespace, then exit
86 // back to the base accept state.
87 $this->addExitPattern("\s","ininstance");
90 // Patterns to handle strings of the form userid:foo
92 // If we see the string userid: while in the base accept state, start
93 // parsing a username and go to the inuserid state.
94 $this->addEntryPattern("userid:\S+","accept","inuserid");
96 // Snarf everything into the username until we see whitespace, then exit
97 // back to the base accept state.
98 $this->addExitPattern("\s","inuserid");
101 // Patterns to handle strings of the form user:foo
103 // If we see the string user: while in the base accept state, start
104 // parsing a username and go to the inusername state.
105 $this->addEntryPattern("user:\S+","accept","inusername");
107 // Snarf everything into the username until we see whitespace, then exit
108 // back to the base accept state.
109 $this->addExitPattern("\s","inusername");
112 // Patterns to handle strings of the form meta:foo
114 // If we see the string meta: while in the base accept state, start
115 // parsing a username and go to the inmeta state.
116 $this->addEntryPattern("subject:\S+","accept","inmeta");
118 // Snarf everything into the meta token until we see whitespace, then exit
119 // back to the base accept state.
120 $this->addExitPattern("\s","inmeta");
123 // Patterns to handle required exact match strings (+foo) .
125 // If we see a + sign while in the base accept state, start
126 // parsing an exact match string and enter the inrequired state
127 $this->addEntryPattern("\+\S+","accept","inrequired");
128 // When we see white space, exit back to accept state.
129 $this->addExitPattern("\s","inrequired");
131 // Handle excluded strings (-foo)
133 // If we see a - sign while in the base accept state, start
134 // parsing an excluded string and enter the inexcluded state
135 $this->addEntryPattern("\-\S+","accept","inexcluded");
136 // When we see white space, exit back to accept state.
137 $this->addExitPattern("\s","inexcluded");
140 // Patterns to handle quoted strings.
142 // If we see a quote while in the base accept state, start
143 // parsing a quoted string and enter the inquotedstring state.
144 // Grab everything until we see the closing quote.
146 $this->addEntryPattern("\"[^\"]+","accept","inquotedstring");
148 // When we see a closing quote, reenter the base accept state.
149 $this->addExitPattern("\"","inquotedstring");
151 // Patterns to handle ordinary, nonquoted words.
153 // When we see non-whitespace, snarf everything into the nonquoted word
154 // until we see whitespace again.
155 $this->addEntryPattern("\S+","accept","plainstring");
157 // Once we see whitespace, reenter the base accept state.
158 $this->addExitPattern("\s","plainstring");
166 // This class takes care of sticking the proper token type/value pairs into
167 // the parsed token array.
168 // Most functions in this class should only be called by the lexer, the
169 // one exception being getParseArray() which returns the result.
171 class search_parser
{
175 // This function is called by the code that's interested in the result of the parse operation.
176 function get_parsed_array(){
177 return $this->tokens
;
181 * Functions below this are part of the state machine for the parse
182 * operation and should not be called directly.
185 // Base state. No output emitted.
190 // State for handling datefrom:foo constructs. Potentially emits a token.
191 function indatefrom($content){
192 if (strlen($content) < 10) { // State exit or missing parameter.
195 // Strip off the datefrom: part and add the reminder to the parsed token array
196 $param = trim(substr($content,9));
197 $this->tokens
[] = new search_token(TOKEN_DATEFROM
,$param);
201 // State for handling dateto:foo constructs. Potentially emits a token.
202 function indateto($content){
203 if (strlen($content) < 8) { // State exit or missing parameter.
206 // Strip off the dateto: part and add the reminder to the parsed token array
207 $param = trim(substr($content,7));
208 $this->tokens
[] = new search_token(TOKEN_DATETO
,$param);
212 // State for handling instance:foo constructs. Potentially emits a token.
213 function ininstance($content){
214 if (strlen($content) < 10) { // State exit or missing parameter.
217 // Strip off the instance: part and add the reminder to the parsed token array
218 $param = trim(substr($content,9));
219 $this->tokens
[] = new search_token(TOKEN_INSTANCE
,$param);
224 // State for handling userid:foo constructs. Potentially emits a token.
225 function inuserid($content){
226 if (strlen($content) < 8) { // State exit or missing parameter.
229 // Strip off the userid: part and add the reminder to the parsed token array
230 $param = trim(substr($content,7));
231 $this->tokens
[] = new search_token(TOKEN_USERID
,$param);
236 // State for handling user:foo constructs. Potentially emits a token.
237 function inusername($content){
238 if (strlen($content) < 6) { // State exit or missing parameter.
241 // Strip off the user: part and add the reminder to the parsed token array
242 $param = trim(substr($content,5));
243 $this->tokens
[] = new search_token(TOKEN_USER
,$param);
248 // State for handling meta:foo constructs. Potentially emits a token.
249 function inmeta($content){
250 if (strlen($content) < 9) { // Missing parameter.
253 // Strip off the meta: part and add the reminder to the parsed token array.
254 $param = trim(substr($content,8));
255 $this->tokens
[] = new search_token(TOKEN_META
,$param);
260 // State entered when we've seen a required string (+foo). Potentially
262 function inrequired($content){
263 if (strlen($content) < 2) { // State exit or missing parameter, don't emit.
266 // Strip off the + sign and add the reminder to the parsed token array.
267 $this->tokens
[] = new search_token(TOKEN_EXACT
,substr($content,1));
271 // State entered when we've seen an excluded string (-foo). Potentially
273 function inexcluded($content){
274 if (strlen($content) < 2) { // State exit or missing parameter.
277 // Strip off the -sign and add the reminder to the parsed token array.
278 $this->tokens
[] = new search_token(TOKEN_NEGATE
,substr($content,1));
283 // State entered when we've seen a quoted string. Potentially emits a token.
284 function inquotedstring($content){
285 if (strlen($content) < 2) { // State exit or missing parameter.
288 // Strip off the opening quote and add the reminder to the parsed token array.
289 $this->tokens
[] = new search_token(TOKEN_STRING
,substr($content,1));
293 // State entered when we've seen an ordinary, non-quoted word. Potentially
295 function plainstring($content){
296 if (ctype_space($content)) { // State exit
299 // Add the string to the parsed token array.
300 $this->tokens
[] = new search_token(TOKEN_STRING
,$content);
306 // Primitive function to generate a SQL string from a parse tree.
309 // $parsetree should be a parse tree generated by a
310 // search_lexer/search_parser combination.
311 // Other fields are database table names to search.
313 function search_generate_SQL($parsetree, $datafield, $metafield, $mainidfield, $useridfield,
314 $userfirstnamefield, $userlastnamefield, $timefield, $instancefield) {
317 if ($CFG->dbtype
== "postgres7") {
318 $LIKE = "ILIKE"; // case-insensitive
319 $NOTLIKE = "NOT ILIKE"; // case-insensitive
324 $NOTLIKE = "NOT LIKE";
326 $NOTREGEXP = "NOT REGEXP";
329 $ntokens = count($parsetree);
336 for ($i=0; $i<$ntokens; $i++
){
337 if ($i > 0) {// We have more than one clause, need to tack on AND
338 $SQLString .= ' AND ';
341 $type = $parsetree[$i]->getType();
342 $value = $parsetree[$i]->getValue();
346 $SQLString .= "(($datafield $LIKE '%$value%') OR ($metafield $LIKE '%$value%') )";
349 $SQLString .= "(($datafield $REGEXP '[[:<:]]".$value."[[:>:]]') OR ($metafield $REGEXP '[[:<:]]".$value."[[:>:]]'))";
352 if ($metafield != '') {
353 $SQLString .= "($metafield $LIKE '%$value%')";
357 $SQLString .= "(($mainidfield = $useridfield) AND (($userfirstnamefield $LIKE '%$value%') OR ($userlastnamefield $LIKE '%$value%')))";
360 $SQLString .= "($useridfield = $value)";
363 $SQLString .= "($instancefield = $value)";
366 $SQLString .= "($timefield <= $value)";
369 $SQLString .= "($timefield >= $value)";
372 $SQLString .= "(NOT (($datafield $LIKE '%$value%') OR ($metafield $LIKE '%$value%')))";