Rss-Bridge/lib/Exceptions.php
LogMANOriginal b90bcee1fc
Return exceptions in requested feed formats (#841)
* [Exceptions] Don't return header for bridge exceptions
* [Exceptions] Add link to list in exception message

This is an alternative when the button is not rendered
for some reason.

* [index] Don't return bridge exception for formats
* [index] Return feed item for bridge exceptions
* [BridgeAbstract] Rename 'getCacheTime' to 'getModifiedTime'
* [BridgeAbstract] Move caching to index.php to separate concerns

index.php needs more control over caching behavior in order to cache
exceptions. This cannot be done in a bridge, as the bridge might be
broken, thus preventing caching from working.

This also (and more importantly) separates concerns. The bridge should
not even care if caching is involved or not. Its purpose is to collect
and provide data.

Response times should be faster, as more complex bridge functions like
'setDatas' (evaluates all input parameters to predict the current
context) and 'collectData' (collects data from sites) can be skipped
entirely.

Notice: In its current form, index.php takes care of caching. This
could, however, be moved into a separate class (i.e. CacheAbstract)
in order to make implementation details cache specific.

* [index] Add '_error_time' parameter to $item['uri']

This ensures that error messages are recognized by feed readers as
new errors after 24 hours. During that time the same item is returned
no matter how often the cache is cleared.

References https://github.com/RSS-Bridge/rss-bridge/issues/814#issuecomment-420876162

* [index] Include '_error_time' in the title for errors

This prevents feed readers from "updating" feeds based on the title

* [index] Handle "HTTP_IF_MODIFIED_SINCE" client requests

Implementation is based on `BridgeAbstract::dieIfNotModified()`,
introduced in 422c125d8e and
simplified based on https://stackoverflow.com/a/10847262

Basically, before returning cached data we check if the client send
the "HTTP_IF_MODIFIED_SINCE" header. If the modification time is
more recent or equal to the cache time, we reply with "HTTP/1.1 304
 Not Modified" (same as before). Otherwise send the cached data.

* [index] Don't encode exception message with `htmlspecialchars`
* [Exceptions] Include error message in exception
* [index] Show different error message for error code 0
2018-10-15 17:21:43 +02:00

158 lines
4.4 KiB
PHP

<?php
class HttpException extends \Exception{}
/**
* Returns an URL that automatically populates a new issue on GitHub based
* on the information provided
*
* @param $title string Sets the title of the issue
* @param $body string Sets the body of the issue (GitHub markdown applies)
* @param $labels mixed (optional) Specifies labels to add to the issue
* @param $maintainer string (optional) Specifies the maintainer for the issue.
* The maintainer only applies if part of the development team!
* @return string Returns a qualified URL to a new issue with populated conent.
* Returns null if title or body is null or empty
*/
function buildGitHubIssueQuery($title, $body, $labels = null, $maintainer = null){
if(!isset($title) || !isset($body) || empty($title) || empty($body)) {
return null;
}
// Add title and body
$uri = 'https://github.com/rss-bridge/rss-bridge/issues/new?title='
. urlencode($title)
. '&body='
. urlencode($body);
// Add labels
if(!is_null($labels) && is_array($labels) && count($labels) > 0) {
if(count($lables) === 1) {
$uri .= '&labels=' . urlencode($labels[0]);
} else {
foreach($labels as $label) {
$uri .= '&labels[]=' . urlencode($label);
}
}
} elseif(!is_null($labels) && is_string($labels)) {
$uri .= '&labels=' . urlencode($labels);
}
// Add maintainer
if(!empty($maintainer)) {
$uri .= '&assignee=' . urlencode($maintainer);
}
return $uri;
}
/**
* Returns the exception message as HTML string
*
* @param $e Exception The exception to show
* @param $bridge object The bridge object
* @return string Returns the exception as HTML string. Returns null if the
* provided parameter are invalid
*/
function buildBridgeException($e, $bridge){
if(( !($e instanceof \Exception) && !($e instanceof \Error)) || !($bridge instanceof \BridgeInterface)) {
return null;
}
$title = $bridge->getName() . ' failed with error ' . $e->getCode();
// Build a GitHub compatible message
$body = 'Error message: `'
. $e->getMessage()
. "`\nQuery string: `"
. $_SERVER['QUERY_STRING']
. "`\nVersion: `"
. Configuration::getVersion()
. '`';
$body_html = nl2br($body);
$link = buildGitHubIssueQuery($title, $body, 'bug report', $bridge->getMaintainer());
$header = buildHeader($e, $bridge);
$message = <<<EOD
<strong>{$bridge->getName()}</strong> was unable to receive or process the
remote website's content!<br>
{$body_html}
EOD;
$section = buildSection($e, $bridge, $message, $link);
return $section;
}
/**
* Returns the exception message as HTML string
*
* @param $e Exception The exception to show
* @param $bridge object The bridge object
* @return string Returns the exception as HTML string. Returns null if the
* provided parameter are invalid
*/
function buildTransformException($e, $bridge){
if(( !($e instanceof \Exception) && !($e instanceof \Error)) || !($bridge instanceof \BridgeInterface)) {
return null;
}
$title = $bridge->getName() . ' failed with error ' . $e->getCode();
// Build a GitHub compatible message
$body = 'Error message: `'
. $e->getMessage()
. "`\nQuery string: `"
. $_SERVER['QUERY_STRING'] . '`';
$link = buildGitHubIssueQuery($title, $body, 'bug report', $bridge->getMaintainer());
$header = buildHeader($e, $bridge);
$message = "RSS-Bridge was unable to transform the contents returned by
<strong>{$bridge->getName()}</strong>!";
$section = buildSection($e, $bridge, $message, $link);
return buildPage($title, $header, $section);
}
function buildHeader($e, $bridge){
return <<<EOD
<header>
<h1>Error {$e->getCode()}</h1>
<h2>{$e->getMessage()}</h2>
<p class="status">{$bridge->getName()}</p>
</header>
EOD;
}
function buildSection($e, $bridge, $message, $link){
return <<<EOD
<section>
<p class="exception-message">{$message}</p>
<div class="advice">
<ul class="advice">
<li>Press Return to check your input parameters</li>
<li>Press F5 to retry</li>
<li>Open a <a href="{$link}">GitHub Issue</a> if this error persists</li>
</ul>
</div>
<a href="{$link}" title="After clicking this button you can review
the issue before submitting it"><button>Open GitHub Issue</button></a>
<p class="maintainer">{$bridge->getMaintainer()}</p>
</section>
EOD;
}
function buildPage($title, $header, $section){
return <<<EOD
<!DOCTYPE html>
<html lang="en">
<head>
<title>{$title}</title>
<link href="static/style.css" rel="stylesheet">
</head>
<body>
{$header}
{$section}
</body>
</html>
EOD;
}