/* Copyright 1997 Acorn Computers Ltd
*
* 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.
*/
/***************************************************/
/* File : Meta.c */
/* */
/* Purpose: Handling META tags. */
/* */
/* Author : A.D.Hodgkinson */
/* */
/* History: 25-Jul-97: Created. */
/***************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "swis.h"
#include "flex.h"
#include "HTMLLib.h" /* HTML library API, Which will include html2_ext.h, tags.h and struct.h */
#include "wimp.h"
#include "wimplib.h"
#include "event.h"
#include "svcprint.h"
#include "Global.h"
#include "Utils.h"
#include "Browser.h"
#include "FetchPage.h"
#include "URLutils.h"
#include "Meta.h"
/* Static function prototypes */
static _kernel_oserror * meta_process_refresh(browser_data * b, HStream * t, const char * content);
/*************************************************/
/* meta_process_tag() */
/* */
/* In HTML, META tags can contain a great */
/* variety of information (so much so that this */
/* source file is entirely dedicated to them). */
/* This function is the entry point for dealing */
/* with a new META tag. */
/* */
/* Parameters: Pointer to a browser_data struct */
/* relevant to the token stream */
/* holding the META tag; */
/* */
/* Pointer to the token representing */
/* the META tag. */
/*************************************************/
_kernel_oserror * meta_process_tag(browser_data * b, HStream * t)
{
const char * name;
const char * equiv;
const char * content;
const char * scheme;
if (!t || !b) return NULL;
/* Extract information from the token */
name = HtmlMETAname (t);
equiv = HtmlMETAhttp_equiv(t);
content = HtmlMETAcontent (t);
scheme = HtmlMETAscheme (t);
/* Work out what to do */
if (!utils_strcasecmp(equiv, "refresh"))
{
/* Refresh - load a new page or reload the current page */
/* after a certain amount of time */
if (choices.client_pull)
{
return meta_process_refresh(b, t, content);
}
}
return NULL;
}
/*************************************************/
/* meta_process_refresh() */
/* */
/* Handles META tags specify that a page */
/* refresh (reload) should occur at some time. */
/* */
/* Parameters: Pointer to a browser_data struct */
/* relevant to the META tag; */
/* */
/* The content string for the tag. */
/*************************************************/
static _kernel_oserror * meta_process_refresh(browser_data * b, HStream * t, const char * content)
{
_kernel_oserror * e;
char * separator;
int time_now;
if (!content || !b) return NULL;
/* See if there's any URL specified - else it's the current page that is to be refetched */
separator = strchr(content, ';');
if (!separator) separator = strchr(content, ',');
/* If we found a separator, skip white space */
if (separator)
{
separator ++;
while (*separator && *separator < 33) separator++;
if (!*separator) separator = NULL;
else
{
int success = 0;
/* May have a 'url=' before the actual URL, */
/* or 'name=' in some broken examples... */
if (!utils_strncasecmp(separator, "url", 3)) success = 3;
else if (!utils_strncasecmp(separator, "name", 4)) success = 4;
if (success)
{
char * oldsep = separator;
separator += success;
/* Skip any white space */
while (*separator && *separator < 33) separator++;
/* Should be at an '='; if not, sssume 'url' was the URL to fetch! */
if (*separator != '=') separator = oldsep;
else
{
/* Skip the '=' and any more white space */
separator ++;
while (*separator && *separator < 33) separator++;
/* Should be at the URL now, but make sure... */
if (!*separator) separator = NULL;
}
}
}
}
/* Work out the URL to fetch */
b->meta_refresh_url = HtmlRelativiseURL(browser_current_url(b),
separator ? separator : "",
t);
/* Only proceed if HtmlRelativiseURL didn't fail */
if (b->meta_refresh_url)
{
/* Work out what time to fetch at */
e = _swix(OS_ReadMonotonicTime,
_OUT(0),
&time_now);
if (e) return e;
b->meta_refresh_at = -atoi(content); /* Mark this as 'pending' with a value <= 0 */
/* Install the handler */
register_null_claimant(Wimp_ENull, (WimpEventHandler *) meta_check_refresh, b);
}
return NULL;
}
/*************************************************/
/* meta_check_refresh() */
/* */
/* After a META tag specifying a page (re)load */
/* (refresh) has been processed, this null */
/* handler will initiate the appropriate fetch */
/* after the appropriate delay. */
/* */
/* Paramters are as standard for a Wimp event */
/* handler. */
/*************************************************/
int meta_check_refresh(int eventcode, WimpPollBlock * b, IdBlock * idb, browser_data * handle)
{
int time_now;
/* Nothing to do if we're still fetching */
if (handle->anim_handler) return 0;
/* Otherwise, check the current time */
_swix(OS_ReadMonotonicTime,
_OUT(0),
&time_now);
/* If we've stopped fetching, change the refresh field from */
/* <= 0 to show 'pending' to an actual time when the new */
/* fetch should start. */
if (handle->meta_refresh_at <= 0)
{
handle->meta_refresh_at = (100 * -handle->meta_refresh_at) + time_now; /* ('* 100' for seconds -> centiseconds) */
}
/* Exit if we haven't reached the fetch time */
if (time_now < handle->meta_refresh_at) return 0;
/* Otherwise, deregister this handler and start the fetch */
deregister_null_claimant(Wimp_ENull, (WimpEventHandler *) meta_check_refresh, handle);
handle->meta_refresh_at = 0;
/* If we're on the same page, force an uncached fetch - NB, if */
/* you don't set reloading you'll need to modify the top of */
/* fetchpage_preprocessed where it deals with checking for a */
/* fragment (jump to a named anchor). Otherwise client pull on */
/* sites such as http://jupiter.beseen.com/chat/rooms/g/1678/ */
/* will fail. */
if (
browser_current_url(handle) &&
!urlutils_urlsscmp(handle->meta_refresh_url,
browser_current_url(handle))
)
handle->reloading = 1;
ChkError(fetchpage_new(handle,
handle->meta_refresh_url,
1,
0));
handle->meta_refresh_url = NULL;
return 0;
}
/*************************************************/
/* meta_cancel_refresh() */
/* */
/* Cancels any registered null handler to deal */
/* with client pull (through */
/* META HTTP-EQUIV="Refresh"). */
/* */
/* Does not clear the browser-local 'client */
/* pull' flag. */
/* */
/* Parameters: Pointer to a browser_data struct */
/* relevant to the handler. */
/*************************************************/
void meta_cancel_refresh(browser_data * b)
{
if (b->meta_refresh_url && b->meta_refresh_at)
{
deregister_null_claimant(Wimp_ENull, (WimpEventHandler *) meta_check_refresh, b);
b->meta_refresh_at = 0;
b->meta_refresh_url = NULL;
}
}