Fossil

**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains code used to manage a cookie that stores user-specific
** display preferences for the web interface.
**
** cookie_parse(zNameOfCookie);
** cookie_parse(void);
**
**    Identify a cookie that will be used to remember display choices
**    made by the user, so that those same choices are selected automatically
**    the next time the page is presented.  This routine must be invoked
**    first, to initialize this module.
**    Read and parse the display preferences cookie.
**
** cookie_read_parameter(zQP, zPName);
**
**    If query parameter zQP does not exist but zPName does exist in
**    the parsed cookie, then initialize zQP to hold the same value
**    as the zPName element in the parsed cookie.
**
** cookie_write_parameter(zQP, zPName);
** cookie_write_parameter(zQP, zPName, zDefault);
**
**    If query parameter zQP exists and if it has a different value from
**    the zPName parameter in the parsed cookie, then replace the value of
**    zPName with the value of zQP.  If zQP exists but zPName does not
**    exist, then zPName is created.  If zQP does not exist or if it has
**    the same value as zPName, then this routine is a no-op.
**
** cookie_link_parameter(zQP, zPName);
** cookie_link_parameter(zQP, zPName, zDefault);
**
**    This does both cookie_read_parameter() and cookie_write_parameter()
**    all at once.
**
** cookie_render();
**
**    If any prior calls to cookie_write_parameter() have changed the
**    value of the user preferences cookie, this routine will cause the
**    new cookie value to be included in the HTTP header for the current
**    web page.  This routine is a destructor for this module and should
**    be called once.
**
** char *cookie_value(zPName, zDefault);
**
**    Look up the value of a cookie parameter zPName.  Return zDefault if
**    there is no display preferences cookie or if zPName does not exist.
*/
#include "cookies.h"
#include <assert.h>
#include <string.h>

#if INTERFACE
/* the standard name of the display settings cookie for fossil */
# define DISPLAY_SETTINGS_COOKIE    "fossil_display_settings"
#endif


/*
** State information private to this module
*/
#define COOKIE_NPARAM  10
static struct {
  const char *zCookieName;    /* name of the user preferences cookie */
  char *zCookieValue;         /* Value of the user preferences cookie */
  int bChanged;               /* True if any value has changed */
  int bIsInit;                /* True after initialization */
  int nParam;                 /* Number of parameters in the cookie */
  struct {
    const char *zPName;         /* Name of a parameter */
    char *zPValue;              /* Value of that parameter */
  } aParam[COOKIE_NPARAM];
} cookies;

/* Initialize this module by parsing the content of the cookie named
** by zCookieName
*/
void cookie_parse(const char *zCookieName){
void cookie_parse(void){
  char *z;
  assert( cookies.zCookieName==0 );
  if( cookies.bIsInit ) return;
  cookies.zCookieName = zCookieName;
  z = (char*)P(zCookieName);
  z = (char*)P(DISPLAY_SETTINGS_COOKIE);
  if( z==0 ) z = "";
  cookies.zCookieValue = z = mprintf("%s", z);
  cookies.bIsInit = 1;
  while( cookies.nParam<COOKIE_NPARAM ){
    while( fossil_isspace(z[0]) ) z++;
    if( z[0]==0 ) break;
    cookies.aParam[cookies.nParam].zPName = z;
    while( *z && *z!='=' && *z!=',' ){ z++; }
    if( *z=='=' ){
      *z = 0;

  const char *zQP,        /* Name of the query parameter */
  const char *zPName,     /* Name of the cooking setting */
  const char *zDflt,      /* Default value for the query parameter */
  int flags               /* READ or WRITE or both */
){
  const char *zQVal = P(zQP);
  int i;
  assert( cookies.zCookieName!=0 );
  cookie_parse();
  for(i=0; i<cookies.nParam && strcmp(zPName,cookies.aParam[i].zPName); i++){}
  if( zQVal==0 && (flags & COOKIE_READ)!=0 && i<cookies.nParam ){
    cgi_set_parameter_nocopy(zQP, cookies.aParam[i].zPValue, 1);
    return;
  }
  if( zQVal==0 ) zQVal = zDflt;
  if( (flags & COOKIE_WRITE)!=0

  cookie_readwrite(zQP, zPName, zDflt, COOKIE_READ|COOKIE_WRITE);
}

/* Update the user preferences cookie, if necessary, and shut down this
** module
*/
void cookie_render(void){
  assert( cookies.zCookieName!=0 );
  if( cookies.bChanged ){
    Blob new;
    int i;
    blob_init(&new, 0, 0);
    for(i=0;i<cookies.nParam;i++){
      if( i>0 ) blob_append(&new, ",", 1);
      blob_appendf(&new, "%s=%T",
          cookies.aParam[i].zPName, cookies.aParam[i].zPValue);
    }
    cgi_set_cookie(cookies.zCookieName, blob_str(&new), 0, 31536000);
    cgi_set_cookie(DISPLAY_SETTINGS_COOKIE, blob_str(&new), 0, 31536000);
  }
  cookies.zCookieName = 0;
  cookies.bIsInit = 0;
}

/* Return the value of a preference cookie.
*/
const char *cookie_value(const char *zPName, const char *zDefault){
  int i;
  assert( zPName!=0 );
  cookie_parse();
  for(i=0; i<cookies.nParam && strcmp(zPName,cookies.aParam[i].zPName); i++){}
  return i<cookies.nParam ? cookies.aParam[i].zPValue : zDefault;
}

/*
** WEBPAGE:  cookies
**
** Show the current display settings contained in the
** "fossil_display_settings" cookie.
*/
void cookie_page(void){
  int i;
  if( PB("clear") ){
    cgi_set_cookie(DISPLAY_SETTINGS_COOKIE, "", 0, 1);
    cgi_replace_parameter(DISPLAY_SETTINGS_COOKIE, "");
  }
  cookie_parse(DISPLAY_SETTINGS_COOKIE);
  cookie_parse();
  style_header("User Preference Cookie Values");
  if( cookies.nParam ){
    style_submenu_element("Clear", "%R/cookies?clear");
  }
  @ <p>The following are user preference settings held in the
  @ "fossil_display_settings" cookie.
  @ <ul>