result_sets=Array(); $this->bindings=Array(); } function _tokenize($exp) { $exprs=Array(); $current=''; $level=0; $tok = strtok($exp," \n\t"); while ($tok) { // Now see if there's a "{" in the token or a "}" in the token for($i=0;$i0) { $exprs[]=$current; $current=''; } } } $current.=$tok.' '; $tok = strtok(" \n\t"); } if(strlen($current)>0) { $exprs[]=$current; $current=$tok; } return $exprs; } // This function is the "main" function of the flwr-lite engine, it evaluates a flwr expression // returning an XML fragment as a string. // The function won't be called only for top-level flwr expressions but for inner sub-expressions // recursively as well. function evaluate_xqueryl($expr) { $result=''; $qexpr=''; $i=0; $chr=substr($expr,$i,1); $level=0; $query=''; while($i0) && ($chr<>'{')) || ($level>1)) { $query.=$chr; } if($chr=='}') { if($level==0) { if(strlen($query)>0) { $result.=$this->_parse_query($query); } $query=''; } } if( ($chr<>"{") && ($chr<>"}") &&($level==0) ){ $result.=$chr; } $i++; $chr=substr($expr,$i,1); } return $result; } // This function returns the root element tagname of an XML // fragment that is later used for auto-adding the root // path to path expressions function _get_root_name($node) { $name=$node->node_name(); return $name; } // This parses a flwr-lite FOR expression binding and // returns the name of the flwr-lite variable associated // the nodeset is stored in the result_sets array. // A flwr-lite FOR expression can be: // FOR $name IN xmlmem($xml)/xpath_expression // or // FOR $name IN xmldoc($xml)/xpath_expression // or // FOR $name IN $name/xpath_expression function _parse_for($expr) { $result=''; $tokens=split(" ",$expr); $name=$tokens[1]; if(strtoupper($tokens[2])<>"IN") { trigger_error("Invalid FOR expresion $expr
",E_USER_WARNING); return false; } $path=$tokens[3]; // while the beginning of path is not $ or document then // queues the function and repeat $functions=Array(); $cosa=substr($path,0,6); while( (substr($path,0,1)<>'$') && (substr($path,0,8)<>"document") && (substr($path,0,6)<>"xmlmem")) { preg_match("/([^(]*)\((.*)\)/",$path,$regs); $path=$regs[2]; $path=substr($path,0,strlen($path)); array_unshift($functions,$regs[1]); } $parts=explode("/",$path,2); $xml_source=$parts[0]; $path='/'.$parts[1]; // Source maybe xmldoc($path) // or xmlmem($xml) // or $x if(substr($xml_source,0,8)=='document') { /* PROCESSING FROM A FILE */ ereg("document\((.*)\)",$xml_source,$regs); $source=$regs[1]; $name_doc=str_replace('"','',$source); if(!file_exists($name_doc)) { trigger_error("$name_doc file not found", E_USER_WARNING); } $doc=xmldocfile($name_doc); //$rootname=_get_root_name($doc->document_element()); //$path='/'.$rootname.$path; if(!$doc) { trigger_error("XML source document $name_doc was not well formed",E_USER_WARNING); } $xpath=$doc->xpath_init(); $ctx = $doc->xpath_new_context(); $result=$ctx->xpath_eval($path); $nodes=$result->nodeset; foreach($functions as $f) { if($f=="distinct-values") {$f="distinct";} $nodes=$this->$f($nodes); } $nodeset=Array(); foreach($nodes as $node) { if($node->node_type()==XML_ATTRIBUTE_NODE) { $nodeset[]=$node->value; } else { $nodeset[]=$node->dump_node($node); } } unset($xpath); unset($doc); unset($cts); unset($result); } elseif(substr($xml_source,0,6)=='xmlmem') { /* PROCESSING FROM MEM */ ereg("xmlmem\((.*)\)",$xml_source,$regs); $source=$regs[1]; $source=str_replace('"','',$source); $name_var=substr($source,1); // NOTE THAT THE XML STRING MUST BE GLOBAL if(!isset($GLOBALS[$name_var])) { trigger_error("$name_var is not visible from here plase use a global string for XML data",E_USER_WARNING); return false; } $data=$GLOBALS[$name_var]; if(strlen($data)>0) { $doc=xmldoc($data); $rootname=$this->_get_root_name($doc->document_element()); //$path='/'.$rootname.$path; if(!$doc) { trigger_error("XML source was not well formed",E_USER_WARNING); } $xpath=$doc->xpath_init(); $ctx = $doc->xpath_new_context(); $result=$ctx->xpath_eval($path); $nodes=$result->nodeset; foreach($functions as $f) { if($f=="distinct-values") {$f="distinct";} $nodes=$this->$f($nodes); } $nodeset=Array(); foreach($nodes as $node) { if($node->node_type()==XML_ATTRIBUTE_NODE) { $nodeset[]=$node->value; } else { $nodeset[]=$node->dump_node($node); } } } unset($xpath); unset($doc); unset($cts); unset($result); } elseif(substr($xml_source,0,1)=='$') { /* PROCESS FROM A VARIABLE */ //ereg("xmlmem\((.*)\)",$xml_source,$regs); $source=$xml_source; $var_name=substr($source,1); $data=$this->bindings[$var_name]; if(strlen($data)>0) { $doc=xmldoc($data); $rootname=$this->_get_root_name($doc->document_element()); $path='/'.$rootname.$path; if(!$doc) { trigger_error("XML source variable $name_var was not well formed",E_USER_WARNING); } $xpath=$doc->xpath_init(); $ctx = $doc->xpath_new_context(); $result=$ctx->xpath_eval($path); $nodes=$result->nodeset; foreach($functions as $f) { if($f=="distinct-values") {$f="distinct";} $nodes=$this->$f($nodes); } $nodeset=Array(); foreach($nodes as $node) { if($node->node_type()==XML_ATTRIBUTE_NODE) { $nodeset=$node->value; } else { $nodeset[]=$node->dump_node($node); } } } unset($xpath); unset($doc); unset($cts); unset($result); } else { trigger_error("Invalid xml source $xml_source
",E_USER_WARNING); return false; } $name_of_name=substr($name,1); // Here's where the node_set is set but (but!) we may need to apply a function $this->result_sets[$name_of_name]=$nodeset; return $name_of_name; } // Functions that can be applied to a resulting nodeset of a FOR expression // List: _distinct-values // This function eliminate duplicate results from the nodeset // We store a normalized representation of each node in the nodeset and function _distinct($nodeset) { $new_nodeset=Array(); $seen=Array(); $cant=count($nodeset); foreach($nodeset as $node) { $normalized=$this->normalize_elements($node); if(!in_array($normalized,$seen)) { $new_nodeset[]=$node; $seen[]=$normalized; } } $cant=count($new_nodeset); return $new_nodeset; } // Normalize can eliminate all the tags // If the node has only one child and it is text then just the text is returned function _normalize_elements($node) { if($node->node_type()==XML_ATTRIBUTE_NODE) { return $node->value; } $data=trim($node->dump_node($node)); preg_match_all("/<([^>]*)>[^<]*<\/[^>]*>/",$data,$foo); if(count($foo[1])==1) { $data=trim(preg_replace("/<.*>(.*)<\/.*>/","$1",$data)); } else { if($node->node_type()==XML_ELEMENT_NODE) { $data=preg_replace("/\n/"," ",$data); $data=preg_replace("/\t/"," ",$data); $data=preg_replace("/\>\s*\<",$data); } } return $data; } // This function parses an expression in the form: // $name/xpath_expression // outside a FOR expression so it aways returns a // string, if the xpath expression returned an element // the element is normalized. function _parse_var($expr,$norm) { $result=''; // If it is a var is $name/expr $parts=explode("/",$expr,2); $var_name=substr($parts[0],1); if(strlen($parts[1])>0) { $path="/".$parts[1]; } $data=$this->bindings[$var_name]; if(strlen($data)==0) { return ''; } if(strlen($path)>0) { $doc=xmldoc($data); $rootname=$this->_get_root_name($doc->document_element()); $path='/'.$rootname.$path; if(!$doc) { trigger_error("cannot evaluate a xpath expression because $data is not xml ",E_USER_WARNING); } $xpath=$doc->xpath_init(); $ctx = $doc->xpath_new_context(); $result_xp=$ctx->xpath_eval($path); $nodes=$result_xp->nodeset; if(count($nodes)>0) { foreach($nodes as $a_node ) { if($norm) { $res=$this->_normalize_elements($a_node); $result.=$res; } else { if($a_node->node_type()==XML_ATTRIBUTE_NODE) { $res=$a_node->value; $result.=$res; } else { $res=$a_node->dump_node($a_node); $result.=$res; } } } } else { $result=''; } } else { $result=$data; /* $doc=xmldoc($data); $root=$doc->document_element($doc); if($norm) { $result=_normalize_elements($root); } else { print("El resultado es el dump simple
"); if($root->node_type()==XML_ATTRIBUTE_NODE) { print("dumping an attribute
"); $result=$root->value; } else { $result=$root->dump_node($root); } } */ } unset($xpath); unset($ctx); unset($result_xp); unset($doc); return $result; } // This function is very similar to _parse_var BUT // instead of returning the result or the variable // it just counts the number of elements in the nodeset function _count_var($expr) { $result=''; // If it is a var is $name/expr $parts=explode("/",$expr,2); $var_name=substr($parts[0],1); if(strlen($parts[1])>0) { $path="/".$parts[1]; } $data=$this->bindings[$var_name]; if(strlen($data)==0) { return ''; } if(strlen($path)>0) { $doc=xmldoc($data); $rootname=$this->_get_root_name($doc->document_element()); $path='/'.$rootname.$path; if(!$doc) { trigger_error("cannot evaluate a xpath expression because $data is not xml ",E_USER_WARNING); } $xpath=$doc->xpath_init(); $ctx = $doc->xpath_new_context(); $result_xp=$ctx->xpath_eval($path); $nodes=$result_xp->nodeset; unset($xpath); unset($ctx); unset($result_xp); unset($doc); return count($nodes); } else { return 1; //$result=$data; /* $doc=xmldoc($data); $root=$doc->document_element($doc); if($norm) { $result=_normalize_elements($root); } else { print("El resultado es el dump simple
"); if($root->node_type()==XML_ATTRIBUTE_NODE) { print("dumping an attribute
"); $result=$root->value; } else { $result=$root->dump_node($root); } } */ } return $result; } // This function parses a flwr-lite where expression returning // true/false depending on the expression value // First flwr variables followed or not by an expression are // evaluated and replaced by their values // then and/or are replaced by &&/|| // then a PHP eval construction is used to eval the expression // :TODO: code this function function _parse_where($expr) { $result=true; $expr=ltrim($expr); $wexpr=substr($expr,5); $wexpr=preg_replace("/([^A-Za-z0-9])and([^A-Za-z0-9])/","$1&&$2",$wexpr); $wexpr=preg_replace("/([^A-Za-z0-9])or([^A-Za-z0-9])/","$1||$2",$wexpr); $wexpr=preg_replace("/([^=>_count_var($counts[1][$i]); $cosa=$counts[0][$i]; $wexpr=str_replace($cosa,"$cant",$wexpr); } $vars=Array(); $is_a_var=false; $a_var=''; for($i=0;$i','<','+','-','*',';',"\n"))) { $is_a_var=false; } } if(!$is_a_var) { $vars[]=$a_var; $a_var=''; } } if($is_a_var && $chr<>"$") { $a_var.=$chr; } } if($is_a_var) { $vars[]=$a_var; } // Now each variable must be evaluated foreach($vars as $exp) { $exp='$'.$exp; $ret=$this->_parse_var($exp,1); // And now strreplace $exp for the value $ret='"'.$ret.'"'; $wexpr=str_replace($exp,$ret,$wexpr); } $php_code='return('.$wexpr.');'; $result=eval($php_code); return $result; } // This function parses a flwr-lite RETURN expression // basically a return expression just contains the word // RETURN followed by another flwr-lite query that can // contain flwr-lite expressions. function _parse_return($expr) { $expr=ltrim($expr); $result=''; // A return expr is $retexp=substr($expr,6); $sub=$this->evaluate_xqueryl($retexp); return $sub; } // This function parses a flwr-lite LET expression // a LET statement only binds an evaluation to a variable // name // Let won't normalize path expressions function parse_let($expr) { $expr=ltrim($expr); // A let is in the form LET $name := value $letexpr=substr($expr,4); $tokens=split(":=",$letexpr); $var_name=$tokens[0]; $var_value=$tokens[1]; $var_value=trim($var_value); $var_name=trim($var_name); if(strstr($var_value,'$')) { // We are assigning to a var value //$var_value=substr($var_value,1); $var_value=$this->_parse_var($var_value,false); } $var_name=substr($var_name,1); $this->bindings[$var_name]=$var_value; } function _split_fors($expr) { $fors=Array(); $afor=''; $level=0; for($i=0;$i0) { $fors[]=$afor; $afor=''; } } else { $afor.=$chr; } } if(strlen($afor)>0) { $fors[]=$afor; $afor=''; } return $fors; } // This function parses a flwr-lite expression // this function is called after filtering out XML constructs from // a flwr-lite query function _parse_query($query) { $result=''; $exprs=$this->_tokenize($query); $expr=array_shift($exprs); $expr=trim($expr); $tokens=split(" ",$expr); $what=trim($tokens[0]); if(substr($what,0,1)=="$") { $result.=$this->_parse_var($what,0); } else { switch(strtoupper($what)) { case "FOR": // This produces a result-set // and then the rest of the expression // is evaluated for each element in the // node set // Expresion should be split in commas // but don't count commas inside pairs of [] $multi_fors=$this->_split_fors($expr); if(count($multi_fors)>1) { // then we have to append for lines next for($i=count($multi_fors)-1;$i>0;$i--) { $afor=ltrim($multi_fors[$i]); if(strtoupper(substr($afor,3))<>'FOR') { $afor='FOR '.$afor; } $afor=rtrim($afor); array_unshift($exprs,$afor); } $expr=$multi_fors[0]; } $name=$this->_parse_for($expr); $nodes=$this->result_sets[$name]; foreach($nodes as $node) { $this->bindings[$name]=$node; $query=implode("\n",$exprs); // What follows the FOR expr $result.=$this->_parse_query($query); // is parsed } break; case "WHERE": // If we have a where then the rest is evaluated only if the WHERE is true if($this->_parse_where($expr)) { // :TODO: cambiar el implode $query=implode("\n",$exprs); $result.=$this->_parse_query($query); } break; case "RETURN": // If we have a return we parse the return and nothing can follow a return // Theres nothing after a return $result.=$this->_parse_return($expr); break; case "LET": // Parse the LET statement and continue evaluating the query $this->parse_let($expr); // :TODO: cambiar el implode $query=implode("\n",$exprs); $result.=$this->_parse_query($query); break; default: // If we have something else (whitespace I hope) we process what follows // :TODO: cambiar el implode $query=implode("\n",$exprs); $result.=$this->_parse_query($query); } } return $result; } } /* $case1=' { for $b in xmlmem($bib)/bib/book where $b/publisher = "Addison-Wesley" and $b/@year > 1991 return { $b/title } } '; $bib=' StevensW. Addison-Wesley 65.95 StevensW. Addison-Wesley 65.95 AbiteboulSerge BunemanPeter SuciuDan Morgan Kaufmann Publishers 39.95 GerbargDarcy CITI Kluwer Academic Publishers 129.95 '; $xq=new XqueryLite(); $result=$xq->evaluate_xqueryl($case1); print("Result:
"); print("$result"); */ ?>