balxml_utf8readerwrapper.h

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/// @file balxml_utf8readerwrapper.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// balxml_utf8readerwrapper.h                                         -*-C++-*-
#ifndef INCLUDED_BALXML_UTF8READERWRAPPER
#define INCLUDED_BALXML_UTF8READERWRAPPER
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup balxml_utf8readerwrapper balxml_utf8readerwrapper
/// @brief  Provide wrapper for `Reader` to check input UTF-8 validity.
/// @addtogroup bal
/// @{
/// @addtogroup balxml
/// @{
/// @addtogroup balxml_utf8readerwrapper
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#balxml_utf8readerwrapper-purpose"> Purpose</a>
/// * <a href="#balxml_utf8readerwrapper-classes"> Classes </a>
/// * <a href="#balxml_utf8readerwrapper-description"> Description </a>
///   * <a href="#balxml_utf8readerwrapper-usage"> Usage </a>
///     * <a href="#balxml_utf8readerwrapper-example-1-routine-parsing"> Example 1: Routine Parsing: </a>
///
/// # Purpose {#balxml_utf8readerwrapper-purpose}
/// Provide wrapper for `Reader` to check input UTF-8 validity.
///
/// # Classes {#balxml_utf8readerwrapper-classes}
///
/// -   balxml::Utf8ReaderWrapper: Wrap a `Reader`, check UTF-8 input.
///
/// @see  balxml_reader, balxml_errorinfo, bdlde_utf8streambufinputwrapper
///
/// # Description {#balxml_utf8readerwrapper-description}
/// This component supplies a mechanism,
/// `balxml::Utf8ReaderWrapper`, which holds another object of type
/// `balxml::Reader` and forwards operations to the held object.  The held
/// object is to operate on a `bsl::streambuf`, which is in fact a
/// `bdlde::Utf8CheckingInStreamBufWrapper` contained in the object, which holds
/// another `bsl::streambuf` and forward actions to that held `bsl::streambuf`.
///
/// The `bdlde_Utf8StreamBufInputWrapper` detects invalid UTF-8.  If the input
/// contains nothing but valid UTF-8, the `bdlde_Utf8StreamBufInputWrapper`
/// simply forwards all operations to the `bsl::streambuf` it holds, and the
/// wrapper has no influence on behavior.
///
/// Similarly, if the input contains nothing but valid UTF-8, the reader wrapper
/// simply forwards all operations to the held `Reader` and has no influence on
/// behavior.
///
/// If invalid UTF-8 occurs in the input, `errorInfo().message()` will reflect
/// the nature of the UTF-8 error.
///
/// ## Usage {#balxml_utf8readerwrapper-usage}
///
///
/// This section illustrates intended use of this component.
///
/// ### Example 1: Routine Parsing: {#balxml_utf8readerwrapper-example-1-routine-parsing}
///
///
/// Utility function to skip past white space.
/// @code
/// int advancePastWhiteSpace(balxml::Reader& reader)
/// {
///     static const char whiteSpace[] = "\n\r\t ";
///     const char *value = 0;
///     int         type = 0;
///     int         rc = 0;
///
///     do {
///         rc    = reader.advanceToNextNode();
///         value = reader.nodeValue();
///         type  = reader.nodeType();
///     } while ((0 == rc && type == balxml::Reader::e_NODE_TYPE_WHITESPACE) ||
///              (type == balxml::Reader::e_NODE_TYPE_TEXT &&
///               bsl::strlen(value) == bsl::strspn(value, whiteSpace)));
///
///     assert( reader.nodeType() != balxml::Reader::e_NODE_TYPE_WHITESPACE);
///
///     return rc;
/// }
/// @endcode
/// Then, in `main`, we parse an XML string using the UTF-8 reader wrapper:
///
/// The following string describes xml for a very simple user directory.  The
/// top level element contains one xml namespace attribute, with one embedded
/// entry describing a user.  The person's name contains some non-ascii UTF-8.
/// @code
/// static const char TEST_XML_STRING[] =
///    "<?xml version='1.0' encoding='UTF-8'?>\n"
///    "<directory-entry xmlns:dir='http://bloomberg.com/schemas/directory'>\n"
///    "    <name>John Smith\xe7\x8f\x8f</name>\n"
///    "    <phone dir:phonetype='cell'>212-318-2000</phone>\n"
///    "    <address/>\n"
///    "</directory-entry>\n";
/// @endcode
/// In order to read the XML, we first need to construct a
/// `balxml::NamespaceRegistry` object, a `balxml::PrefixStack` object, and a
/// `Utf8ReaderWrapper` object.
/// @code
/// balxml::NamespaceRegistry namespaces;
/// balxml::PrefixStack prefixStack(&namespaces);
/// balxml::MiniReader miniReader;
/// balxml::Utf8ReaderWrapper reader(&miniReader);
///
/// assert(!reader.isOpen());
/// @endcode
/// The reader uses a `balxml::PrefixStack` to manage namespace prefixes so we
/// need to set it before we call open.
/// @code
/// reader.setPrefixStack(&prefixStack);
/// assert(reader.prefixStack());
/// assert(reader.prefixStack() == &prefixStack);
/// @endcode
/// Now we call the `open` method to setup the reader for parsing using the data
/// contained in the in the XML string.
/// @code
/// reader.open(TEST_XML_STRING, sizeof(TEST_XML_STRING) -1, 0, "UTF-8");
/// @endcode
/// Confirm that the `bdem::Reader` has opened properly
/// @code
/// assert( reader.isOpen());
/// assert(!bsl::strncmp(reader.documentEncoding(), "UTF-8", 5));
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_NONE);
/// assert(!reader.nodeName());
/// assert(!reader.nodeHasValue());
/// assert(!reader.nodeValue());
/// assert(!reader.nodeDepth());
/// assert(!reader.numAttributes());
/// assert(!reader.isEmptyElement());
/// @endcode
/// Advance through all the nodes and assert all information contained at each
/// node is correct.
///
/// Assert the next node's document type is xml.
/// @code
/// int rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() ==
///                           balxml::Reader::e_NODE_TYPE_XML_DECLARATION);
/// assert(!bsl::strcmp(reader.nodeName(), "xml"));
/// assert( reader.nodeHasValue());
/// assert(!bsl::strcmp(reader.nodeValue(), "version='1.0' encoding='UTF-8'"));
/// assert( reader.nodeDepth() == 1);
/// assert(!reader.numAttributes());
/// assert(!reader.isEmptyElement());
/// assert( 0 == rc);
/// assert( reader.nodeDepth() == 1);
/// @endcode
/// Advance to the top level element, which has one attribute, the xml
/// namespace.  Assert the namespace information has been added correctly to the
/// prefix stack.
/// @code
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "directory-entry"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 1);
/// assert( reader.numAttributes() == 1);
/// assert(!reader.isEmptyElement());
///
/// assert(!bsl::strcmp(prefixStack.lookupNamespacePrefix("dir"), "dir"));
/// assert(prefixStack.lookupNamespaceId("dir") == 0);
/// assert(!bsl::strcmp(prefixStack.lookupNamespaceUri("dir"),
///                     "http://bloomberg.com/schemas/directory"));
/// @endcode
/// The XML being read contains one entry describing a user, advance the users
/// name name and assert all information can be read correctly.
/// @code
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "name"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 2);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
///
/// rc = reader.advanceToNextNode();
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_TEXT);
/// assert( reader.nodeHasValue());
/// assert(!bsl::strcmp(reader.nodeValue(), "John Smith\xe7\x8f\x8f"));
/// assert( reader.nodeDepth() == 3);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
///
/// rc = reader.advanceToNextNode();
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_END_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "name"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 2);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
/// @endcode
/// Advance to the user's phone number and assert all information can be read
/// correctly.
/// @code
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "phone"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 2);
/// assert( reader.numAttributes() == 1);
/// assert(!reader.isEmptyElement());
/// @endcode
/// The phone node has one attribute, look it up and assert the
/// `balxml::ElementAttribute` contains valid information and that the prefix
/// returns the correct namespace URI from the prefix stack.
/// @code
/// balxml::ElementAttribute elemAttr;
///
/// rc = reader.lookupAttribute(&elemAttr, 0);
/// assert( 0 == rc);
/// assert(!elemAttr.isNull());
/// assert(!bsl::strcmp(elemAttr.qualifiedName(), "dir:phonetype"));
/// assert(!bsl::strcmp(elemAttr.value(), "cell"));
/// assert(!bsl::strcmp(elemAttr.prefix(), "dir"));
/// assert(!bsl::strcmp(elemAttr.localName(), "phonetype"));
/// assert(!bsl::strcmp(elemAttr.namespaceUri(),
///                     "http://bloomberg.com/schemas/directory"));
/// assert( elemAttr.namespaceId() == 0);
///
/// assert(!bsl::strcmp(prefixStack.lookupNamespaceUri(elemAttr.prefix()),
///                     elemAttr.namespaceUri()));
///
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_TEXT);
/// assert( reader.nodeHasValue());
/// assert(!bsl::strcmp(reader.nodeValue(), "212-318-2000"));
/// assert( reader.nodeDepth() == 3);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
///
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_END_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "phone"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 2);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
/// @endcode
/// Advance to the user's address and assert all information can be read
/// correctly.
/// @code
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "address"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 2);
/// assert( reader.numAttributes() == 0);
/// assert( reader.isEmptyElement());
/// @endcode
/// Advance to the end element.
/// @code
/// rc = advancePastWhiteSpace(reader);
/// assert( 0 == rc);
/// assert( reader.nodeType() == balxml::Reader::e_NODE_TYPE_END_ELEMENT);
/// assert(!bsl::strcmp(reader.nodeName(), "directory-entry"));
/// assert(!reader.nodeHasValue());
/// assert( reader.nodeDepth() == 1);
/// assert( reader.numAttributes() == 0);
/// assert(!reader.isEmptyElement());
/// @endcode
/// Close the reader.
/// @code
/// reader.close();
/// assert(!reader.isOpen());
///
/// return 0;
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bal
 * @{
 */
/** @addtogroup balxml
 * @{
 */
/** @addtogroup balxml_utf8readerwrapper
 * @{
 */
 
#include <balscm_version.h>
 
#include <balxml_errorinfo.h>
#include <balxml_reader.h>
 
#include <bdlde_utf8checkinginstreambufwrapper.h>
#include <bdlsb_fixedmeminstreambuf.h>
 
#include <bslmf_nestedtraitdeclaration.h>
#include <bsls_keyword.h>
 
#include <bsl_cstddef.h> // for size_t
#include <bsl_functional.h>
#include <bsl_fstream.h>
#include <bsl_streambuf.h>
 
 
namespace balxml {
 
class ElementAttribute;
class ErrorInfo;
class PrefixStack;
 
                            // =======================
                            // class Utf8ReaderWrapper
                            // =======================
 
/// This class "has a" pointer to a held and wrapped `Reader` object, and
/// operations on this object are passed to the held reader.  The held
/// reader is passed a `Utf8CheckingInStreamBufWrapper`, which holds and
/// wraps a normal `streambuf`.  The `Utf8CheckingInStreamBufWrapper` checks
/// input for invalid UTF-8, and if it detects any, makes the diagnosis of
/// the problem available through the `errorInfo` accessor.
///
/// See @ref balxml_utf8readerwrapper 
class Utf8ReaderWrapper : public Reader {
 
    // DATA
    bdlde::Utf8CheckingInStreamBufWrapper d_utf8StreamBuf;
    bdlsb::FixedMemInStreamBuf            d_fixedStreamBuf;
    bsl::ifstream                         d_stream;
    Reader *                              d_reader_p;
    ErrorInfo                             d_errorInfo;
    bool                                  d_useHeldErrorInfo;
 
  private:
    // NOT IMPLEMENTED
    Utf8ReaderWrapper(const Utf8ReaderWrapper&);
    Utf8ReaderWrapper& operator=(const Utf8ReaderWrapper&);
 
  public:
    // TRAITS
    BSLMF_NESTED_TRAIT_DECLARATION(Utf8ReaderWrapper,
                                   bslma::UsesBslmaAllocator);
 
  private:
    // PRIVATE MANIPULATORS
 
    /// Open the held reader with `d_utf8StreamBuf`, as well as the specified `url` and `encoding`.  
    /// 
    /// \note Note that   all public `open`
    /// functions of this class prepare `d_utf8StreamBuf` and then delegate
    /// to this function as part of their implementation.
    int doOpen(const char *url, const char *encoding);
 
    /// Return a pointer providing modifiable access to the held `Reader`.
    Reader *heldReader();
 
    /// Called when a UTF-8 error is encountered, to make `d_errorInfo` into
    /// a combination of `heldReader()->errorInfo()` and the nature of the
    /// UTF-8 error as reported by the specified `utf8Rc`.  
    /// 
    /// \pre The behavior is undefined   unless `utf8Rc < 0` and `utf8Rc` is one of the values
    /// enumerated by `Utf8Util::ErrorStatus`.
    void reportUtf8Error(int utf8Rc);
 
    // PRIVATE ACCESSORS
 
    /// Return a pointer providing non-modifiable access to the held
    /// `Reader`.
    const Reader *heldReader() const;
 
  public:
    // CREATORS
 
    /// Create a `Utf8ReaderWrapper` that holds the specified `reader`.
    /// Optionally specify a `basicAllocator` used to supply memory.  If
    /// `basicAllocator` is 0, the currently installed default allocator is used.  
    /// 
    /// \pre The behavior is undefined   unless `reader` has never been
    /// opened or closed.
    explicit
    Utf8ReaderWrapper(Reader           *reader,
                      bslma::Allocator *basicAllocator = 0);
 
    /// Close the held reader and destroy this object.
    ~Utf8ReaderWrapper() BSLS_KEYWORD_OVERRIDE;
 
    // MANIPULATORS
 
                              // ** setup methods **
 
    /// Set the options of the held reader to the flags in the specified
    /// `flags`.  The options for the reader are persistent, i.e., the options are not reset by `close`.  
    /// 
    /// \pre The behavior is undefined   if this
    /// method is called after calling `open` and before calling `close`;
    /// except that derived classes are permitted to specify valid behavior
    /// for calling this function for specific arguments while the reader is
    /// open.
    void setOptions(unsigned int flags) BSLS_KEYWORD_OVERRIDE;
 
    /// Set the prefix stack to the stack at the optionally specified
    /// `prefixes` address or disable prefix stack support if `prefixes` is
    /// null.  This stack is used to push and pop namespace prefixes as the
    /// parse progresses, so that, at any point, the stack will reflect the
    /// set of active prefixes for the current node.  It is legitimate to
    /// pass a stack that already contains prefixes, these prefixes shall be
    /// preserved when `close` is called, i.e., the prefix stack shall be
    /// returned to the stack depth it had when `setPrefixStack` was called. 
    /// 
    /// \pre The behavior is undefined   if this method is called after calling
    /// `open` and before calling `close`.
    void setPrefixStack(PrefixStack *prefixes) BSLS_KEYWORD_OVERRIDE;
 
    /// Set the external XML resource resolver to the specified `resolver`.
    /// The XML resource resolver is used by the @ref balxml_reader  to find and
    /// open an external resources (See the `XmlResolverFunctor` typedef for
    /// more details).  The XML resource resolver remains valid; it is not
    /// affected by a call to `close` and should be available until the reader is destroyed.  
    /// 
    /// \pre The behavior is undefined   if this method is
    /// called after calling `open` and before calling `close`.
    void setResolver(XmlResolverFunctor resolver) BSLS_KEYWORD_OVERRIDE;
 
                            // ** open/close methods **
 
    /// Set up the reader for parsing using the data contained in the XML
    /// file described by the specified `filename`, and set the encoding
    /// value to the optionally specified `encoding` ("ASCII", "UTF-8",
    /// etc).  Returns 0 on success and non-zero otherwise.  The encoding
    /// passed to `Reader::open` will take effect only when there is no
    /// encoding information in the original document, i.e., the encoding
    /// information obtained from the XML file described by the `filename`
    /// trumps all.  If there is no encoding provided within the document
    /// and `encoding` is null or a blank string is passed, then set the
    /// encoding to the default "UTF-8".  It is an error to `open` a reader that is already open.  
    /// 
    /// \note Note that   the reader will not be on a valid
    /// node until `advanceToNextNode` is called.
    int open(const char *filename, const char *encoding = 0)
                                                         BSLS_KEYWORD_OVERRIDE;
 
    /// Set up the reader for parsing using the data contained in the
    /// specified (XML) `buffer` of the specified `size`, set the base URL
    /// to the optionally specified `url` and set the encoding value to the
    /// optionally specified `encoding` ("ASCII", "UTF-8", etc).  Return 0
    /// on success and non-zero otherwise.  If `url` is null or a blank
    /// string is passed, then base URL will be empty.  The encoding passed
    /// to `Reader::open` will take effect only when there is no encoding
    /// information in the original document, i.e., the encoding information
    /// obtained from the (XML) `buffer` trumps all.  If there is no
    /// encoding provided within the document and `encoding` is null or a
    /// blank string is passed, then set the encoding to the default
    /// "UTF-8".  It is an error to `open` a reader that is already open. 
    /// 
    /// \note Note that   the reader will not be on a valid node until
    /// `advanceToNextNode` is called.
    int open(const char  *buffer,
             bsl::size_t  size,
             const char  *url = 0,
             const char  *encoding = 0) BSLS_KEYWORD_OVERRIDE;
 
    /// Set up the reader for parsing using the data contained in the
    /// specified (XML) `stream`, set the base URL to the optionally
    /// specified `url` and set the encoding value to the optionally
    /// specified `encoding` ("ASCII", "UTF-8", etc).  Return 0 on success
    /// and non-zero otherwise.  If `url` is null or a blank string is
    /// passed, then base URL will be empty.  The encoding passed to
    /// `Reader::open` will take effect only when there is no encoding
    /// information in the original document, i.e., the encoding information
    /// obtained from the (XML) `stream` trumps all.  If there is no
    /// encoding provided within the document and `encoding` is null or a
    /// blank string is passed, then set the encoding to the default
    /// "UTF-8".  It is an error to `open` a reader that is already open. 
    /// 
    /// \note Note that   the reader will not be on a valid node until
    /// `advanceToNextNode` is called.
    int open(bsl::streambuf *stream,
             const char     *url = 0,
             const char     *encoding = 0) BSLS_KEYWORD_OVERRIDE;
 
    /// Close the reader.  Most, but not all state is reset.  Specifically,
    /// the XML resource resolver and the prefix stack remain.  The prefix
    /// stack shall be returned to the stack depth it had when
    /// `setPrefixStack` was called.  Call the method `open` to reuse the reader.  
    /// 
    /// \note Note that   `close` invalidates all strings and data
    /// structures obtained via `Reader` accessors.  E.g., the pointer
    /// returned from `nodeName` for this node will not be valid once
    /// `close` is called.
    void close() BSLS_KEYWORD_OVERRIDE;
 
                                // ** navigation method **
 
    /// Move to the next node in the data steam created by `open` thus
    /// allowing the node's properties to be queried via the `Reader`
    /// accessors.  Return 0 on successful read, 1 if there are no more nodes to read, and a negative number otherwise.  
    /// 
    /// \note Note that   each call
    /// to `advanceToNextNode` invalidates strings and data structures
    /// returned when `Reader` accessors where call for the "prior node".
    /// E.g., the pointer returned from `nodeName` for this node will not be valid once `advanceToNextNode` is called.  
    /// 
    /// \note Note that   the reader will
    /// not be on a valid node until the first call to `advanceToNextNode`
    /// after the reader is opened.
    int advanceToNextNode() BSLS_KEYWORD_OVERRIDE;
 
    // ACCESSORS
 
    /// Return the allocator used by this object to allocate memory.
    bslma::Allocator *allocator() const;
 
    /// Return the document encoding or NULL on error.  The returned poiner
    /// is owned by this object and must not be modified or deallocated by
    /// the caller.  The returned pointer becomes invalid when `close` is
    /// called or the reader is destroyed.
    const char *documentEncoding() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return a reference to the non-modifiable error information for this
    /// reader.  The returned value becomes invalid when `close` is called
    /// or the reader is destroyed.
    const ErrorInfo& errorInfo() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the current column number within the input stream.  The
    /// current column number is the number of characters since the last
    /// newline was read by the reader plus one, i.e., the first column of
    /// each line is column number one.  Return 0 if not available.  
    /// 
    /// \note Note that   a derived-class implementation is not required to count
    /// columns and may just return 0.
    int getColumnNumber() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the current line number within the input stream.  The current
    /// line is the last line for which the reader has not yet seen a
    /// newline.  Lines are counted starting at one from the time a stream is provided to `open`.  Return 0 if not available.  
    /// 
    /// \note Note that   a
    /// derived-class implementation is not required to count lines and may
    /// just return 0.
    int getLineNumber() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return true if the current node is an element (i.e., node type is
    /// `BAEXML_NODE_TYPE_ELEMENT`) that ends with `/>`; and false otherwise.  
    /// 
    /// \note Note that   `<a/>` will be considered empty but `<a></a>`
    /// will not.
    bool isEmptyElement() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return true if `open` was called successfully and `close` has not
    /// yet been called and false otherwise.
    bool isOpen() const BSLS_KEYWORD_OVERRIDE;
 
    /// Find the attribute at the specified `index` in the current node, and
    /// fill in the specified `attribute` structure.  Return 0 on success, 1
    /// if no attribute is found at the `index`, and an a negative value
    /// otherwise.  The strings that were filled into the `attribute`
    /// structure are invalid upon the next `advanceToNextNode` or `close`
    /// is called.
    int lookupAttribute(ElementAttribute *attribute,
                        int               index) const BSLS_KEYWORD_OVERRIDE;
 
    /// Find the attribute with the specified `qname` (qualified name) in
    /// the current node, and fill in the specified `attribute` structure.
    /// Return 0 on success, 1 if there is no attribute found with `qname`,
    /// and a negative value otherwise.  The strings that were filled into
    /// the `attribute` structure are invalid upon the next
    /// `advanceToNextNode` or `close` is called.
    int lookupAttribute(ElementAttribute *attribute,
                        const char       *qname) const BSLS_KEYWORD_OVERRIDE;
 
    /// Find the attribute with the specified `localName` and specified
    /// `namespaceUri` in the current node, and fill in the specified
    /// `attribute` structure.  Return 0 on success, 1 if there is no
    /// attribute found with `localName` and `namespaceUri`, and a negative
    /// value otherwise.  If `namespaceUri` == 0 or a blank string is
    /// passed, then the document's default namespace will be used.  The
    /// strings that were filled into the `attribute` structure are invalid
    /// upon the next `advanceToNextNode` or `close` is called.
    int
    lookupAttribute(
                   ElementAttribute *attribute,
                   const char       *localName,
                   const char       *namespaceUri) const BSLS_KEYWORD_OVERRIDE;
 
    /// Find the attribute with the specified `localName` and specified
    /// `namespaceId` in the current node, and fill in the specified
    /// `attribute` structure.  Return 0 on success, 1 if there is no
    /// attribute found with `localName` and `namespaceId`, and a negative
    /// value otherwise.  If `namespaceId` == -1, then the document's
    /// default namespace will be used.  The strings that were filled into
    /// the `attribute` structure are invalid upon the next
    /// `advanceToNextNode` or `close` is called.
    int lookupAttribute(
                    ElementAttribute *attribute,
                    const char       *localName,
                    int               namespaceId) const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the base URI name of the current node if the current node has
    /// a base URI and NULL otherwise.  The returned pointer is owned by
    /// this object and must not be modified or deallocated by the caller.
    /// The returned pointer becomes invalid upon the next
    /// `advanceToNextNode`, when `close` is called or the reader is
    /// destroyed.
    const char *nodeBaseUri() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the nesting depth of the current node in the XML document.
    /// The root node has depth 0.
    int nodeDepth() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the local name of the current node if the current node has a
    /// local name and NULL otherwise.  The returned pointer is owned by
    /// this object and must not be modified or deallocated by the caller.
    /// The returned pointer becomes invalid upon the next
    /// `advanceToNextNode`, when `close` is called or the reader is
    /// destroyed.
    const char *nodeLocalName() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return true if the current node has a value and false otherwise.
    bool nodeHasValue() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the qualified name of the current node if the current node
    /// has a name and NULL otherwise.  The returned pointer is owned by
    /// this object and must not be modified or deallocated by the caller.
    /// The returned pointer becomes invalid upon the next
    /// `advanceToNextNode`, when `close` is called or the reader is
    /// destroyed.
    const char *nodeName() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the namespace ID of the current node if the current node has
    /// a namespace id and a negative number otherwise.
    int nodeNamespaceId() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the namespace URI name of the current node if the current
    /// node has a namespace URI and NULL otherwise.  The returned pointer
    /// is owned by this object and must not be modified or deallocated by
    /// the caller.  The returned pointer becomes invalid upon the next
    /// `advanceToNextNode`, when `close` is called or the reader is
    /// destroyed.
    const char *nodeNamespaceUri() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the prefix name of the current node if the correct node has a
    /// prefix name and NULL otherwise.  The returned pointer is owned by
    /// this object and must not be modified or deallocated by the caller.
    /// The returned pointer becomes invalid upon the next
    /// `advanceToNextNode`, when `close` is called or the reader is
    /// destroyed.
    const char *nodePrefix() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the node type of the current node if the reader `isOpen` and
    /// has not encounter an error and `Reader::NONE` otherwise.
    NodeType nodeType() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the value of the current node if the current node has a value
    /// and NULL otherwise.  The returned pointer is owned by this object
    /// and must not be modified or deallocated by the caller.  The returned
    /// pointer becomes invalid upon the next `advanceToNextNode`, when
    /// `close` is called or the reader is destroyed.
    const char *nodeValue() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the number of attributes for the current node if that node
    /// has attributes and 0 otherwise.
    int numAttributes() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the option flags.
    unsigned int options() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return a pointer to the modifiable prefix stack that is used by this
    /// reader to manage namespace prefixes or 0 if namespace support is disabled.  
    /// 
    /// \pre The behavior is undefined   if the returned prefix stack is
    /// augmented in any way after calling `open` and before calling
    /// `close`.
    PrefixStack *prefixStack() const BSLS_KEYWORD_OVERRIDE;
 
    /// Return the external XML resource resolver.
    XmlResolverFunctor resolver() const BSLS_KEYWORD_OVERRIDE;
};
 
// ============================================================================
//                            INLINE DEFINITIONS
// ============================================================================
 
                                // ------------
                                // class Reader
                                // ------------
 
// PRIVATE MANIPULATORS
inline
Reader *Utf8ReaderWrapper::heldReader()
{
    return d_reader_p;
}
 
// PRIVATE ACCESSORS
inline
const Reader *Utf8ReaderWrapper::heldReader() const
{
    return d_reader_p;
}
 
}  // close package namespace
 
 
#endif // INCLUDED_BALXML_UTF8READERWRAPPER
 
// ----------------------------------------------------------------------------
// Copyright 2020 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
 
/** @} */
/** @} */
/** @} */