Class: Nokolexbor::XPathContext

Inherits:
Object
  • Object
show all
Defined in:
lib/nokolexbor/xpath_context.rb,
ext/nokolexbor/nl_xpath_context.c

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.new(node) ⇒ Object

Create a new XPathContext with node as the reference point.



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# File 'ext/nokolexbor/nl_xpath_context.c', line 318

static VALUE
nl_xpath_context_new(VALUE klass, VALUE rb_node)
{
  xmlXPathContextPtr ctx;
  VALUE self;

  lxb_dom_node_t *node = nl_rb_node_unwrap(rb_node);

  ctx = nl_xmlXPathNewContext(node->owner_document);
  ctx->node = node;

  nl_xmlXPathRegisterNs(ctx, NOKOGIRI_PREFIX, NOKOGIRI_URI);
  nl_xmlXPathRegisterNs(ctx, NOKOGIRI_BUILTIN_PREFIX, NOKOGIRI_BUILTIN_URI);
  nl_xmlXPathRegisterFuncNS(ctx, (const xmlChar *)"css-class", NOKOGIRI_BUILTIN_URI,
                            xpath_builtin_css_class);
  nl_xmlXPathRegisterFuncNS(ctx, (const xmlChar *)"local-name-is", NOKOGIRI_BUILTIN_URI,
                            xpath_builtin_local_name_is);

  self = Data_Wrap_Struct(klass, 0, free_xml_xpath_context, ctx);
  rb_iv_set(self, "@document", nl_rb_document_get(rb_node));

  return self;
}

Instance Method Details

#evaluate(search_path, handler = nil) ⇒ Object

Evaluate the search_path returning an XML::XPath object.



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# File 'ext/nokolexbor/nl_xpath_context.c', line 265

static VALUE
nl_xpath_context_evaluate(int argc, VALUE *argv, VALUE self)
{
  VALUE search_path, xpath_handler;
  VALUE retval = Qnil;
  xmlXPathContextPtr ctx;
  xmlXPathObjectPtr xpath;
  xmlChar *query;
  VALUE errors = rb_ary_new();

  Data_Get_Struct(self, xmlXPathContext, ctx);

  if (rb_scan_args(argc, argv, "11", &search_path, &xpath_handler) == 1) {
    xpath_handler = Qnil;
  }

  query = (xmlChar *)StringValueCStr(search_path);

  // if (Qnil != xpath_handler) {
  //   /* FIXME: not sure if this is the correct place to shove private data. */
  //   ctx->userData = (void *)xpath_handler;
  //   nl_xmlXPathRegisterFuncLookup(ctx, handler_lookup, (void *)xpath_handler);
  // }

  nl_xmlSetStructuredErrorFunc((void *)errors, nl_xpath_error_array_pusher);
  nl_xmlSetGenericErrorFunc((void *)errors, nl_xpath_generic_exception_pusher);

  xpath = nl_xmlXPathEvalExpression(query, ctx);

  nl_xmlSetStructuredErrorFunc(NULL, NULL);
  nl_xmlSetGenericErrorFunc(NULL, NULL);

  if (xpath == NULL) {
    nl_xmlXPathFreeObject(xpath);
    rb_exc_raise(rb_ary_entry(errors, 0));
  }

  retval = xpath2ruby(xpath, ctx, nl_rb_document_get(self));
  if (retval == Qundef) {
    retval = rb_funcall(cNokolexborNodeSet, rb_intern("new"), 1, rb_ary_new());
  }

  nl_xmlXPathFreeObject(xpath);

  return retval;
}

#register_namespaces(namespaces) ⇒ Object

Register namespaces in namespaces



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# File 'lib/nokolexbor/xpath_context.rb', line 7

def register_namespaces(namespaces)
  namespaces.each do |k, v|
    k = k.to_s.gsub(/.*:/, "") # strip off 'xmlns:' or 'xml:'
    register_ns(k, v)
  end
end

#register_ns(prefix, uri) ⇒ Object

Register the namespace with prefix and uri.



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# File 'ext/nokolexbor/nl_xpath_context.c', line 128

static VALUE
nl_xpath_context_register_ns(VALUE self, VALUE prefix, VALUE uri)
{
  xmlXPathContextPtr ctx;
  Data_Get_Struct(self, xmlXPathContext, ctx);

  nl_xmlXPathRegisterNs(ctx,
                        (const xmlChar *)StringValueCStr(prefix),
                        (const xmlChar *)StringValueCStr(uri));
  return self;
}

#register_variable(name, value) ⇒ Object

Register the variable name with value.



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# File 'ext/nokolexbor/nl_xpath_context.c', line 146

static VALUE
nl_xpath_context_register_variable(VALUE self, VALUE name, VALUE value)
{
  xmlXPathContextPtr ctx;
  xmlXPathObjectPtr xmlValue;
  Data_Get_Struct(self, xmlXPathContext, ctx);

  xmlValue = nl_xmlXPathNewCString(StringValueCStr(value));

  nl_xmlXPathRegisterVariable(ctx,
                              (const xmlChar *)StringValueCStr(name),
                              xmlValue);

  return self;
}