source: vbox/trunk/src/libs/xpcom18a4/xpcom/io/nsEscape.h@ 4837

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/*      First checked in on 98/12/03 by John R. McMullen, derived from net.h/mkparse.c. */

#ifndef _ESCAPE_H_
#define _ESCAPE_H_

#include "prtypes.h"
#include "nscore.h"
#include "nsError.h"
#include "nsString.h"

/**
 * Valid mask values for nsEscape
 */
typedef enum {
        url_XAlphas   = PR_BIT(0) /**< Normal escape - leave alphas intact, escape the rest */
,       url_XPAlphas  = PR_BIT(1) /**< As url_XAlphas, but convert spaces (0x20) to '+' and plus to %2B */
,       url_Path      = PR_BIT(2) /**< As url_XAlphas, but don't escape slash ('/') */
} nsEscapeMask;

#ifdef __cplusplus
extern "C" {
#endif

/**
 * Escape the given string according to mask
 * @param str The string to escape
 * @param mask How to escape the string
 * @return A newly allocated escaped string that must be free'd with
 *         nsCRT::free, or null on failure
 */
NS_COM char * nsEscape(const char * str, nsEscapeMask mask);

NS_COM char * nsUnescape(char * str);
        /* decode % escaped hex codes into character values,
         * modifies the parameter, returns the same buffer
         */

NS_COM PRInt32 nsUnescapeCount (char * str);
        /* decode % escaped hex codes into character values,
         * modifies the parameter buffer, returns the length of the result
         * (result may contain \0's).
         */

NS_COM char *
nsEscapeHTML(const char * string);

NS_COM PRUnichar *
nsEscapeHTML2(const PRUnichar *aSourceBuffer,
              PRInt32 aSourceBufferLen = -1);
 /*
  * Escape problem char's for HTML display 
  */


#ifdef __cplusplus
}
#endif


/**
 * NS_EscapeURL/NS_UnescapeURL constants for |flags| parameter:
 */
enum EscapeMask {
  /** url components **/
  esc_Scheme         = PR_BIT(0),
  esc_Username       = PR_BIT(1),
  esc_Password       = PR_BIT(2),
  esc_Host           = PR_BIT(3),
  esc_Directory      = PR_BIT(4),
  esc_FileBaseName   = PR_BIT(5),
  esc_FileExtension  = PR_BIT(6),
  esc_FilePath       = esc_Directory | esc_FileBaseName | esc_FileExtension,
  esc_Param          = PR_BIT(7),
  esc_Query          = PR_BIT(8),
  esc_Ref            = PR_BIT(9),
  /** special flags **/
  esc_Minimal        = esc_Scheme | esc_Username | esc_Password | esc_Host | esc_FilePath | esc_Param | esc_Query | esc_Ref, 
  esc_Forced         = PR_BIT(10), /* forces escaping of existing escape sequences */
  esc_OnlyASCII      = PR_BIT(11), /* causes non-ascii octets to be skipped */
  esc_OnlyNonASCII   = PR_BIT(12), /* causes _graphic_ ascii octets (0x20-0x7E) 
                                    * to be skipped when escaping. causes all
                                    * ascii octets to be skipped when unescaping */
  esc_AlwaysCopy     = PR_BIT(13), /* copy input to result buf even if escaping is unnecessary */
  esc_Colon          = PR_BIT(14), /* forces escape of colon */
  esc_SkipControl    = PR_BIT(15)  /* skips C0 and DEL from unescaping */
};

/**
 * NS_EscapeURL
 *
 * Escapes invalid char's in an URL segment.  Has no side-effect if the URL
 * segment is already escaped.  Otherwise, the escaped URL segment is appended
 * to |result|.
 *
 * @param  str     url segment string
 * @param  len     url segment string length (-1 if unknown)
 * @param  flags   url segment type flag
 * @param  result  result buffer, untouched if part is already escaped
 *
 * @return TRUE if escaping was performed, FALSE otherwise.
 */
NS_COM PRBool NS_EscapeURL(const char *str,
                           PRInt32 len,
                           PRInt16 flags,
                           nsACString &result);

/**
 * Expands URL escape sequences... beware embedded null bytes!
 *
 * @param  str     url string to unescape
 * @param  len     length of |str|
 * @param  flags   only esc_OnlyNonASCII, esc_SkipControl and esc_AlwaysCopy 
 *                 are recognized
 * @param  result  result buffer, untouched if |str| is already unescaped
 *
 * @return TRUE if unescaping was performed, FALSE otherwise.
 */
NS_COM PRBool NS_UnescapeURL(const char *str,
                             PRInt32 len,
                             PRInt16 flags,
                             nsACString &result);

/** returns resultant string length **/
inline PRInt32 NS_UnescapeURL(char *str) { return nsUnescapeCount(str); }

/**
 * string friendly versions...
 */
inline const nsACString &
NS_EscapeURL(const nsASingleFragmentCString &part, PRInt16 partType, nsACString &result) {
    const char *temp;
    if (NS_EscapeURL(part.BeginReading(temp), part.Length(), partType, result))
        return result;
    return part;
}
inline const nsACString &
NS_UnescapeURL(const nsASingleFragmentCString &str, PRInt16 flags, nsACString &result) {
    const char *temp;
    if (NS_UnescapeURL(str.BeginReading(temp), str.Length(), flags, result))
        return result;
    return str;
}
// inline unescape
inline nsAFlatCString &
NS_UnescapeURL(nsAFlatCString &str)
{
    str.SetLength(nsUnescapeCount(str.BeginWriting()));
    return str;
}

#endif //  _ESCAPE_H_