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/* Please see the LICENSE file for copyright and distribution information */
#include "ruby_libxml.h"
#include "ruby_xml_xpath.h"
#include "ruby_xml_xpath_expression.h"
/*
* Document-class: LibXML::XML::XPath::Expression
*
* The XML::XPath::Expression class is used to compile
* XPath expressions so they can be parsed only once
* but reused multiple times.
*
* doc = XML::Document.string(IO.read('some xml file'))
* expr = XPath::Expression.new('//first')
* doc.root.each do |node|
* result = node.find(expr) # many, many, many times
* # ...
* end
*/
VALUE cXMLXPathExpression;
static void rxml_xpath_expression_free(xmlXPathCompExprPtr expr)
{
xmlXPathFreeCompExpr(expr);
}
static VALUE rxml_xpath_expression_alloc(VALUE klass)
{
return Data_Wrap_Struct(cXMLXPathExpression, NULL,
rxml_xpath_expression_free, NULL);
}
/* call-seq:
* XPath::Expression.compile(expression) -> XPath::Expression
*
* Compiles an XPatch expression. This improves performance
* when an XPath expression is called multiple times.
*
* doc = XML::Document.string('<header><first>hi</first></header>')
* expr = XPath::Expression.new('//first')
* nodes = doc.find(expr)
*/
static VALUE rxml_xpath_expression_compile(VALUE klass, VALUE expression)
{
VALUE args[] = {expression};
return rb_class_new_instance(1, args, cXMLXPathExpression);
}
/* call-seq:
* XPath::Expression.new(expression) -> XPath::Expression
*
* Compiles an XPatch expression. This improves performance
* when an XPath expression is called multiple times.
*
* doc = XML::Document.string('<header><first>hi</first></header>')
* expr = XPath::Expression.new('//first')
* nodes = doc.find(expr)
*/
static VALUE rxml_xpath_expression_initialize(VALUE self, VALUE expression)
{
xmlXPathCompExprPtr compexpr = xmlXPathCompile((const xmlChar*)StringValueCStr(expression));
if (compexpr == NULL)
{
xmlErrorPtr xerror = xmlGetLastError();
rxml_raise(xerror);
}
DATA_PTR( self) = compexpr;
return self;
}
void rxml_init_xpath_expression(void)
{
cXMLXPathExpression = rb_define_class_under(mXPath, "Expression", rb_cObject);
rb_define_alloc_func(cXMLXPathExpression, rxml_xpath_expression_alloc);
rb_define_singleton_method(cXMLXPathExpression, "compile", rxml_xpath_expression_compile, 1);
rb_define_method(cXMLXPathExpression, "initialize", rxml_xpath_expression_initialize, 1);
}
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