iosWebViewFix/lib/assets/web/web_support.js

window.flutter_inappwebview = {
    webViews: {},
    createFlutterInAppWebView: function(viewId, iframeId) {
        var webView = {
            viewId: viewId,
            iframeId: iframeId,
            iframe: null,
            windowAutoincrementId: 0,
            windows: {},
            isFullscreen: false,
            documentTitle: null,
            functionMap: {},
            settings: {},
            disableContextMenuHandler: function(event) {
                event.preventDefault();
                event.stopPropagation();
                return false;
            },
            prepare: function (settings) {
                webView.settings = settings;
                var iframe = document.getElementById(iframeId);

                document.addEventListener('fullscreenchange', function(event) {
                    // document.fullscreenElement will point to the element that
                    // is in fullscreen mode if there is one. If there isn't one,
                    // the value of the property is null.
                    if (document.fullscreenElement && document.fullscreenElement.id == iframeId) {
                        webView.isFullscreen = true;
                        window.flutter_inappwebview.nativeCommunication('onEnterFullscreen', viewId);
                    } else if (!document.fullscreenElement && webView.isFullscreen) {
                        webView.isFullscreen = false;
                        window.flutter_inappwebview.nativeCommunication('onExitFullscreen', viewId);
                    } else {
                        webView.isFullscreen = false;
                    }
                });

                if (iframe != null) {
                    webView.iframe = iframe;
                    iframe.addEventListener('load', function (event) {
                        webView.windowAutoincrementId = 0;
                        webView.windows = {};

                        var url = iframe.src;
                        try {
                            url = iframe.contentWindow.location.href;
                        } catch (e) {
                            console.log(e);
                        }
                        window.flutter_inappwebview.nativeCommunication('onLoadStart', viewId, [url]);

                        try {
                            var oldLogs = {
                                'log': iframe.contentWindow.console.log,
                                'debug': iframe.contentWindow.console.debug,
                                'error': iframe.contentWindow.console.error,
                                'info': iframe.contentWindow.console.info,
                                'warn': iframe.contentWindow.console.warn
                            };
                            for (var k in oldLogs) {
                                (function(oldLog) {
                                    iframe.contentWindow.console[oldLog] = function() {
                                        var message = '';
                                        for (var i in arguments) {
                                            if (message == '') {
                                                message += arguments[i];
                                            } else {
                                                message += ' ' + arguments[i];
                                            }
                                        }
                                        oldLogs[oldLog].call(iframe.contentWindow.console, ...arguments);
                                        window.flutter_inappwebview.nativeCommunication('onConsoleMessage', viewId, [oldLog, message]);
                                    }
                                })(k);
                            }
                        } catch (e) {
                            console.log(e);
                        }

                        try {
                            var originalPushState = iframe.contentWindow.history.pushState;
                            iframe.contentWindow.history.pushState = function (state, unused, url) {
                                originalPushState.call(iframe.contentWindow.history, state, unused, url);
                                var iframeUrl = iframe.src;
                                try {
                                    iframeUrl = iframe.contentWindow.location.href;
                                } catch (e) {
                                    console.log(e);
                                }
                                window.flutter_inappwebview.nativeCommunication('onUpdateVisitedHistory', viewId, [iframeUrl]);
                            };

                            var originalReplaceState = iframe.contentWindow.history.replaceState;
                            iframe.contentWindow.history.replaceState = function (state, unused, url) {
                                originalReplaceState.call(iframe.contentWindow.history, state, unused, url);
                                var iframeUrl = iframe.src;
                                try {
                                    iframeUrl = iframe.contentWindow.location.href;
                                } catch (e) {
                                    console.log(e);
                                }
                                window.flutter_inappwebview.nativeCommunication('onUpdateVisitedHistory', viewId, [iframeUrl]);
                            };

                            var originalOpen = iframe.contentWindow.open;
                            iframe.contentWindow.open = function (url, target, windowFeatures) {
                                var newWindow = originalOpen.call(iframe.contentWindow, ...arguments);
                                var windowId = webView.windowAutoincrementId;
                                webView.windowAutoincrementId++;
                                webView.windows[windowId] = newWindow;
                                window.flutter_inappwebview.nativeCommunication('onCreateWindow', viewId, [windowId, url, target, windowFeatures]).then(function(){}, function(handledByClient) {
                                    if (handledByClient) {
                                        newWindow.close();
                                    }
                                });
                                return newWindow;
                            };

                            var originalPrint = iframe.contentWindow.print;
                            iframe.contentWindow.print = function () {
                                var iframeUrl = iframe.src;
                                try {
                                    iframeUrl = iframe.contentWindow.location.href;
                                } catch (e) {
                                    console.log(e);
                                }
                                window.flutter_inappwebview.nativeCommunication('onPrint', viewId, [iframeUrl]);
                                originalPrint.call(iframe.contentWindow);
                            };

                            webView.functionMap = {
                                "window.open": iframe.contentWindow.open,
                                "window.print": iframe.contentWindow.print,
                                "window.history.pushState": iframe.contentWindow.history.pushState,
                                "window.history.replaceState": iframe.contentWindow.history.replaceState,
                            }

                            var initialTitle = iframe.contentDocument.title;
                            webView.documentTitle = initialTitle;
                            window.flutter_inappwebview.nativeCommunication('onTitleChanged', viewId, [initialTitle]);
                            new MutationObserver(function(mutations) {
                                var title = mutations[0].target.nodeValue;
                                if (title != webView.documentTitle) {
                                    webView.documentTitle = title;
                                    window.flutter_inappwebview.nativeCommunication('onTitleChanged', viewId, [title]);
                                }
                            }).observe(
                                iframe.contentDocument.querySelector('title'),
                                { subtree: true, characterData: true, childList: true }
                            );

                            var oldPixelRatio = iframe.contentWindow.devicePixelRatio;
                            iframe.contentWindow.addEventListener('resize', function (e) {
                                var newPixelRatio = iframe.contentWindow.devicePixelRatio;
                                if(newPixelRatio !== oldPixelRatio){
                                    window.flutter_inappwebview.nativeCommunication('onZoomScaleChanged', viewId, [oldPixelRatio, newPixelRatio]);
                                    oldPixelRatio = newPixelRatio;
                                }
                            });

                            iframe.contentWindow.addEventListener('popstate', function (event) {
                                var iframeUrl = iframe.src;
                                try {
                                    iframeUrl = iframe.contentWindow.location.href;
                                } catch (e) {
                                    console.log(e);
                                }
                                window.flutter_inappwebview.nativeCommunication('onUpdateVisitedHistory', viewId, [iframeUrl]);
                            });

                            iframe.contentWindow.addEventListener('scroll', function (event) {
                                var x = 0;
                                var y = 0;
                                try {
                                    x = iframe.contentWindow.scrollX;
                                    y = iframe.contentWindow.scrollY;
                                } catch (e) {
                                    console.log(e);
                                }
                                window.flutter_inappwebview.nativeCommunication('onScrollChanged', viewId, [x, y]);
                            });

                            iframe.contentWindow.addEventListener('focus', function (event) {
                                window.flutter_inappwebview.nativeCommunication('onWindowFocus', viewId);
                            });

                            iframe.contentWindow.addEventListener('blur', function (event) {
                                window.flutter_inappwebview.nativeCommunication('onWindowBlur', viewId);
                            });
                        } catch (e) {
                            console.log(e);
                        }

                        try {

                            if (!webView.settings.javaScriptCanOpenWindowsAutomatically) {
                                iframe.contentWindow.open = function () {
                                    throw new Error('JavaScript cannot open windows automatically');
                                };
                            }

                            if (!webView.settings.verticalScrollBarEnabled && !webView.settings.horizontalScrollBarEnabled) {
                                var style = iframe.contentDocument.createElement('style');
                                style.id = "settings.verticalScrollBarEnabled-settings.horizontalScrollBarEnabled";
                                style.innerHTML = "body::-webkit-scrollbar { width: 0px; height: 0px; }";
                                iframe.contentDocument.head.append(style);
                            }

                            if (webView.settings.disableVerticalScroll) {
                                var style = iframe.contentDocument.createElement('style');
                                style.id = "settings.disableVerticalScroll";
                                style.innerHTML = "body { overflow-y: hidden; }";
                                iframe.contentDocument.head.append(style);
                            }

                            if (webView.settings.disableHorizontalScroll) {
                                var style = iframe.contentDocument.createElement('style');
                                style.id = "settings.disableHorizontalScroll";
                                style.innerHTML = "body { overflow-x: hidden; }";
                                iframe.contentDocument.head.append(style);
                            }

                            if (webView.settings.disableContextMenu) {
                                iframe.contentWindow.addEventListener('contextmenu', webView.disableContextMenuHandler);
                            }
                        } catch (e) {
                            console.log(e);
                        }

                        window.flutter_inappwebview.nativeCommunication('onLoadStop', viewId, [url]);
                    });
                }
            },
            setSettings: function (newSettings) {
                var iframe = webView.iframe;
                try {
                    if (webView.settings.javaScriptCanOpenWindowsAutomatically != newSettings.javaScriptCanOpenWindowsAutomatically) {
                        if (!newSettings.javaScriptCanOpenWindowsAutomatically) {
                            iframe.contentWindow.open = function () {
                                throw new Error('JavaScript cannot open windows automatically');
                            };
                        } else {
                            iframe.contentWindow.open = webView.functionMap["window.open"];
                        }
                    }

                    if (webView.settings.verticalScrollBarEnabled != newSettings.verticalScrollBarEnabled &&
                        webView.settings.horizontalScrollBarEnabled != newSettings.horizontalScrollBarEnabled) {
                        if (!newSettings.verticalScrollBarEnabled && !newSettings.horizontalScrollBarEnabled) {
                            var style = iframe.contentDocument.createElement('style');
                            style.id = "settings.verticalScrollBarEnabled-settings.horizontalScrollBarEnabled";
                            style.innerHTML = "body::-webkit-scrollbar { width: 0px; height: 0px; }";
                            iframe.contentDocument.head.append(style);
                        } else {
                            var styleElement = iframe.contentDocument.getElementById("settings.verticalScrollBarEnabled-settings.horizontalScrollBarEnabled");
                            if (styleElement) { styleElement.remove() }
                        }
                    }

                    if (webView.settings.disableVerticalScroll != newSettings.disableVerticalScroll) {
                        if (newSettings.disableVerticalScroll) {
                            var style = iframe.contentDocument.createElement('style');
                            style.id = "settings.disableVerticalScroll";
                            style.innerHTML = "body { overflow-y: hidden; }";
                            iframe.contentDocument.head.append(style);
                        } else {
                             var styleElement = iframe.contentDocument.getElementById("settings.disableVerticalScroll");
                            if (styleElement) { styleElement.remove() }
                        }
                    }

                    if (webView.settings.disableHorizontalScroll != newSettings.disableHorizontalScroll) {
                        if (newSettings.disableHorizontalScroll) {
                            var style = iframe.contentDocument.createElement('style');
                            style.id = "settings.disableHorizontalScroll";
                            style.innerHTML = "body { overflow-x: hidden; }";
                            iframe.contentDocument.head.append(style);
                        } else {
                             var styleElement = iframe.contentDocument.getElementById("settings.disableHorizontalScroll");
                            if (styleElement) { styleElement.remove() }
                        }
                    }

                    if (webView.settings.disableContextMenu != newSettings.disableContextMenu) {
                        if (newSettings.disableContextMenu) {
                            iframe.contentWindow.addEventListener('contextmenu', webView.disableContextMenuHandler);
                        } else {
                            iframe.contentWindow.removeEventListener('contextmenu', webView.disableContextMenuHandler);
                        }
                    }
                } catch (e) {
                    console.log(e);
                }

                webView.settings = newSettings;
            },
            reload: function () {
                var iframe = webView.iframe;
                if (iframe != null && iframe.contentWindow != null) {
                    try {
                        iframe.contentWindow.location.reload();
                    } catch (e) {
                        console.log(e);
                        iframe.contentWindow.location.href = iframe.src;
                    }
                }
            },
            goBack: function () {
                var iframe = webView.iframe;
                if (iframe != null) {
                    try {
                        iframe.contentWindow.history.back();
                    } catch (e) {
                        console.log(e);
                    }
                }
            },
            goForward: function () {
                var iframe = webView.iframe;
                if (iframe != null) {
                    try {
                        iframe.contentWindow.history.forward();
                    } catch (e) {
                        console.log(e);
                    }
                }
            },
            goForwardOrForward: function (steps) {
                var iframe = webView.iframe;
                if (iframe != null) {
                    try {
                        iframe.contentWindow.history.go(steps);
                    } catch (e) {
                        console.log(e);
                    }
                }
            },
            evaluateJavascript: function (source) {
                var iframe = webView.iframe;
                var result = null;
                if (iframe != null) {
                    try {
                        result = JSON.stringify(iframe.contentWindow.eval(source));
                    } catch (e) {}
                }
                return result;
            },
            stopLoading: function (steps) {
                var iframe = webView.iframe;
                if (iframe != null) {
                    try {
                        iframe.contentWindow.stop();
                    } catch (e) {
                        console.log(e);
                    }
                }
            }
        };

        return webView;
    },
    getCookieExpirationDate: function(timestamp) {
        return (new Date(timestamp)).toUTCString();
    }
};