/**
* Request a page of responses from the API
*
* A page of responses will be requested if it appears that that page has not
* yet been loaded (tested by checking if the initial element of the page has
* been initialized in the $data array).
*
* @param int $pageNumber Page number to request
* @param bool $forceRefresh (Optional) Force a refresh of backing data, even
* if cached (defaults to `FALSE`)
*
* @return bool `TRUE` if the page is requested, `FALSE` if it is already cached
* (and therefore not requested)
**/
private function requestPageNumber($pageNumber, $forceRefresh = false)
{
if (!isset($this->data[$this->pageNumberToKey($pageNumber)]) || $forceRefresh && isset($this->api)) {
// assume one page if no pagination (and already loaded)
if (isset($this->pagination[CanvasPageLink::CURRENT])) {
$params = $this->pagination[CanvasPageLink::CURRENT]->getParams();
$params[CanvasPageLink::PARAM_PAGE_NUMBER] = $pageNumber;
$page = $this->api->get($this->pagination[CanvasPageLink::CURRENT]->getEndpoint(), $params);
$this->data = array_replace($this->data, $page->data);
return true;
}
}
return false;
}
/**
* Obtain a Canvas API token, if needed.
*
* @param scalar $step optional Where are we in the API token negotiation workflow? (defaults to API_DECISION_NEEDED_STEP -- the beginning)
* @param boolean $skip optional Skip this step (defaults to FALSE)
*
* @throws CanvasAPIviaLTI_Installer_Exception If $step is not a pre-defined *_STEP constant
**/
public static function acquireAPIToken($step = self::API_DECISION_NEEDED_STEP, $skip = false)
{
global $secrets;
// FIXME grown-ups don't program like this
global $metadata;
// FIXME grown-ups don't program like this
global $smarty;
// FIXME grown-ups don't program like this
if ($skip) {
if (isset($metadata['CANVAS_API_TOKEN']) || isset($metadata['CANVAS_API_USER'])) {
$api = new CanvasPest("{$metadata['CANVAS_INSTANCE_URL']}/login/oauth2", $metadata['CANVAS_API_TOKEN']);
$api->delete('token');
unset($metadata['CANVAS_API_TOKEN']);
unset($metadata['CANVAS_API_USER']);
$smarty->addMessage('Existing admin Canvas API token information expunged', 'There was already an administrative access token stored in your
application metadata, and it has now been expunged.');
} else {
$smarty->addMessage('No admin Canvas API token acquired', 'An administrative API token has not been acquired. Users will be asked to
acquire their own API tokens on their first use of the LTI.');
}
} else {
switch ($step) {
case self::API_DECISION_NEEDED_STEP:
$smarty->assign('content', '
<form action="' . $metadata['APP_URL'] . '/admin/oauth.php" method="post">
<label for="url"> Canvas Instance URL <input type="text" name="url" id="url" placeholder="' . $metadata['CANVAS_INSTANCE_URL_PLACEHOLDER'] . '" value="' . (isset($metadata['CANVAS_INSTANCE_URL']) ? $metadata['CANVAS_INSTANCE_URL'] : '') . '" /></label>
<label for="token"> API Access Token <input type="text" name="token" id="token" placeholder="Leave blank to acquire a token interactively" /></label>
<input type="hidden" name="skip" value="0" />
<input type="hidden" name="step" value="' . self::API_DECISION_ENTERED_STEP . '" />
<input type="submit" value="Use administrative token" />
</form>
or
<form action="' . $_SERVER['PHP_SELF'] . '" method="post">
<input type="hidden" name="skip" value="1" />
<input type="hidden" name="step" value="' . self::API_DECISION_ENTERED_STEP . '" />
<input type="submit" value="Require users to acquire individual tokens" />
</form>
');
$smarty->display();
exit;
case self::API_DECISION_ENTERED_STEP:
$oauth = new OAuthNegotiator();
if ($oauth->isAPIToken()) {
$metadata['CANVAS_API_TOKEN'] = $oauth->getToken();
$smarty->addMessage('Admin Canvas API token acquired', 'An administrative API access token has been acquired and stored in your application metadata.', NotificationMessage::GOOD);
}
/* clear the processed step */
unset($_REQUEST['step']);
break;
case self::API_TOKEN_PROVIDED_STEP:
$smarty->addMessage('Admin Canvas API token provided', 'You provided an API access token and it has been stored in your application metadata.');
break;
default:
throw new CanvasAPIviaLTI_Installer_Exception("Unknown step ({$step}) in obtaining API token.", CanvasAPIviaLTI_Installer_Exception::API_STEP_MISMATCH);
}
}
}
