File indexing completed on 2024-05-19 05:01:19

 /*
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2022 Stefano Crocco <stefano.crocco@alice.it>
 
     SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
 */
 
 #ifndef NAVIGATIONRECORDER_H
 #define NAVIGATIONRECORDER_H
 
 #include <QObject>
 #include <QUrl>
 #include <QPointer>
 #include <QWebEngineUrlRequestInfo>
 #include <QMultiHash>
 
 class WebEnginePage;
 
 /**
  * Class used to integrate information from WebEnginePage::acceptNavigationRequest() and from
  * WebEngineUrlRequestInterceptor::interceptRequest()
  *
  * Sometimes it is important to know both which page requested navigating to a given URL and more
  * detailed information about the request itself
  * (for example, whether it is a GET or a POST request). Unfortunately, this kind information is only
  * available to WebEngineUrlRequestInterceptor::interceptRequest() which, in turn, does not have
  * information about which page made a given request. This class provides a workaround for such situation.
  *
  * When a WebEnginePage emits the \link WebEnginePage::mainFrameNavigationRequested mainFrameNavigationRequested() \endlink
  * signal, the corresponding URL, together with the page, is stored in the ::m_pendingNavigations instance variable.
  * WebEngineUrlRequestInterceptor::interceptRequest() calls recordRequestDetails() providing
  * information about the request. This information is associated which made a request for the given
  * URL and which is still pending and the relevant information is stored. That request is then
  * removed from ::m_pendingNavigations. When the page emits the `loadFinished()` signal, or when the
  * page is deleted, all information corresponding to its URL are removed.
  *
  * @note Currently, this class only records whether the request used the POST method.
  * @warning The algorithm described above is heuristic and it cannot guarantee that the association
  * between page and request information is always correct. In particular, if two different pages
  * request the same URL before \link WebEngineUrlRequestInterceptor::interceptRequest interceptRequest() \endlink
  * is called, when \link WebEngineUrlRequestInterceptor::interceptRequest interceptRequest() \endlink is called,
  * there will be no way to know which page the request refers to.
  * In this case, NavigationRecorder makes
  * the arbitrary assumption that the first call to \link WebEngineUrlRequestInterceptor::interceptRequest interceptRequest() \endlink
  * corresponds to the first call to \link WebEnginePage::acceptNavigationRequest() acceptNavigationRequest()\endlink.
  */
 class NavigationRecorder : public QObject
 {
     Q_OBJECT
 
 public:
     /**
      * @brief Constructor
      * @param parent the parent object
      */
     NavigationRecorder(QObject *parent=nullptr);
 
     /**
      * @brief Destructor
      */
     ~NavigationRecorder();
 
     /**
      * @brief Registers a page so that the NavigationRecorder can connect to its signals
      * @param page the page to register
      */
     void registerPage(WebEnginePage *page);
 
     /**
      * @brief Records details about a navigation request
      *
      * This method is called by WebEngineUrlRequestInterceptor when it intercepts a request for
      * a main frame. It matches the URL of the request with the URL of a previous call to
      * \link WebEnginePage::acceptNavigationRequest acceptNavigationRequest()\endlink and stores
      * information about it.
      * @param info the information about the request
      */
     void recordRequestDetails(const QWebEngineUrlRequestInfo &info);
 
     /**
      * @brief Whether the request made by a given page for a given URl is a POST request or not
      * @param url the requested URL
      * @param page the page which made the request
      * @return @c true if a request for @p url by @p page with POST method has been found and `false`
      * otherwise
      * @note a `false` return value may mean that no request for @p url by @p page has been
      * encountered or that it used a different method (typically GET).
      * @warning as explained in the general description of the class, the algorithm to associate
      * requests with pages need not always be 100% accurate
      */
     bool isPostRequest(const QUrl &url, WebEnginePage *page) const;
 
 public slots:
     /**
      * @brief Method called in response to the `WebEnginePage::loadFinished()` signal
      *
      * It removes all information about the given navigation.
      * @param page the page which finished loading
      * @param url the url
      */
     void recordNavigationFinished(WebEnginePage *page, const QUrl &url);
 
 private slots:
     /**
      * @brief Removes all references to deleted pages from the stored data
      */
     void removePage(QObject*);
 
     /**
      * @brief Records a navigation request from a page
      * @param page the page which requested the navigation
      * @param url the requested URL
      */
     void recordNavigation(WebEnginePage *page, const QUrl &url);
 
 private:
     /**
      * @brief A hash containing all POST requests and the pages which made them, grouped by URL
      */
     QMultiHash<QUrl, QPointer<WebEnginePage>> m_postNavigations;
 
     /**
      * @brief A hash containing all the navigation requests for which no call to
      * \link WebEnginePage::acceptNavigationRequest acceptNavigationRequest()\endlink has yet been
      * made, * grouped by URLs
      */
     QMultiHash<QUrl, QPointer<WebEnginePage>> m_pendingNavigations;
 };
 
 #endif // NAVIGATIONRECORDER_H