I have a requirement were in i have to create a view to display webpages with back, forward and refresh button in iOS app.
how to implement this functionality?
Use UIWebView.
Set the delegate to the view controller.
self.webView.delegate = self;
Other remarkable properties,
self.webView.scalesPageToFit = YES;
To load a URLRequest,
[self.webView loadRequest:theRequest];
or for only strings, use
[self.webView loadHTMLString:htmlString baseURL:nil];
And some delegates here. web view has its own history, you can use it by calling its back and forward methods.
#pragma mark - UIWebView delegate
// You can handle your own url scheme or let the web view handle it.
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request
navigationType:(UIWebViewNavigationType)navigationType
{
NSLog(#"url=%#, %#, %#",
request.URL, request.URL.query, request.URL.host);
if (navigationType == UIWebViewNavigationTypeLinkClicked) {
if ([request.URL.scheme compare:#"customescheme"] == NSOrderedSame) {
if ([request.URL.host compare:kSomethingDotCom] == NSOrderedSame) {
[self mymethod];
} else if ([request.URL.host compare:kAnotherDotCom] == NSOrderedSame) {
[self method2];
} else {
NSLog(#"Unsupported service.");
}
return NO;
}
}
return YES;
}
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
[_activityIndicator stopAnimating];
}
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
[_activityIndicator stopAnimating];
[Resources showAlert:#"Could not load." withTitle:#"Error!"];
NSLog(#"%#", [error localizedDescription]);
}
#pragma mark - Actions
- (IBAction)didPressBackButton:(id)sender
{
[_webView goBack];
}
- (IBAction)didPressForwardButton:(id)sender
{
[_webView goForward];
}
Similarly you can have the stop method. To refresh reload the request again. Before going back or forward you can check the methods canGoBack or canGoForward.
See docs at, http://developer.apple.com/library/ios/#documentation/uikit/reference/UIWebView_Class/Reference/Reference.html
It is a piece of cake, all you need is UIWebview component and its delegates and you need to create a custom navigation bar that is it.
Related
For UIWebView, we can get content height by this:
[webView stringByEvaluatingJavaScriptFromString:#"document.body.offsetHeight"]
But WKWebView doesn't have this method and webView.scrollView.contentSize.height is not right.
(void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
{
}
Thank you for your help!
I solved this problem with KVO.
First, addObserver for WKWebView's scrollView's contentSize like this:
addObserver(self, forKeyPath: "webView.scrollView.contentSize", options: .New, context: nil)
And next, receive the change like this:
override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
if keyPath == "webView.scrollView.contentSize" {
if let nsSize = change[NSKeyValueChangeNewKey] as? NSValue {
let height = nsSize.CGSizeValue().height
// Do something here using content height.
}
}
}
It's easy to get webview's content height.
Don't forget to remove observer:
removeObserver(self, forKeyPath: "webView.scrollView.contentSize", context: nil)
I worte this line in deinit.
EDIT:
To get the best possible height calculation, in the end I did a few things to get the best height:
I set the size of the webview to be really large and then load the content.
Once the content is loaded (KVO notification) I resize the view using the method below.
I then run the size function again and I get a new size and resize my view once again.
The above got the most accurate results for me.
ORIGINAL:
I've tried the scroll view KVO and I've tried evaluating javascript on the document, using clientHeight, offsetHeight, etc...
What worked for me eventually is: document.body.scrollHeight. Or use the scrollHeight of your top most element, e.g. a container div.
I listen to the loading WKWebview property changes using KVO:
[webview addObserver: self forKeyPath: NSStringFromSelector(#selector(loading)) options: NSKeyValueObservingOptionNew context: nil];
And then:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
if(object == self.webview && [keyPath isEqualToString: NSStringFromSelector(#selector(loading))]) {
NSNumber *newValue = change[NSKeyValueChangeNewKey];
if(![newValue boolValue]) {
[self updateWebviewFrame];
}
}
}
The updateWebviewFrame implementation:
[self.webview evaluateJavaScript: #"document.body.scrollHeight" completionHandler: ^(id response, NSError *error) {
CGRect frame = self.webview.frame;
frame.size.height = [response floatValue];
self.webview.frame = frame;
}];
You can get it like this:
self.webview.navigationDelegate = self;
- (void)webView:(WKWebView *)webview didFinishNavigation:(WKNavigation *)navigation{
// webview.scrollView.contentSize will equal {0,0} at this point so wait
[self checkIfWKWebViewReallyDidFinishLoading];
}
- (void)checkIfWKWebViewReallyDidFinishLoading{
_contentSize = _webview.scrollView.contentSize;
if (_contentSize.height == 0){
[self performSelector:#selector(WKWebViewDidFinishLoading) withObject:nil afterDelay:0.01];
}
}
WKWebView didn't finish loading, when didFinishNavigation is called - Bug in WKWebView?
WKWebView doesn't use delegation to let you know when content loading is complete.
You can create a new thread to check the status of WKWebView.
override func viewDidLoad() {
super.viewDidLoad()
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0), {
while(self.webView?.loading == true){
sleep(1)
}
dispatch_async(dispatch_get_main_queue(), {
print(self.webView!.scrollView.contentSize.height)
})
})
}
I'm adding FBLoginView to my ViewController < FBLoginViewDelegate >:
FBLoginView *loginview = [[FBLoginView alloc] init];
loginview.frame = CGRectOffset(loginview.frame, 5, 5);
loginview.delegate = self;
[self.view addSubview:loginview];
[loginview sizeToFit];
All the necessary fields in plist (FacebookAppID, FacebookDisplayName, URL Schemes) are all set according to the tutorial. The facebook app is also configured according to the tutorial (bundle ID is set, Facebook login is enabled).
But the login still isn't performed. When I press on "log in", I get redirected to the browser with facebook login, but when it's finished, I'm not logged in the app (loginViewFetchedUserInfo:user: isn't called, "log in" hasn't changed to "log out").
What can be the problem?
Everything worked after I implemented the following in the AppDelegate.m (taken from one of the official examples):
- (void)sessionStateChanged:(FBSession *)session
state:(FBSessionState) state
error:(NSError *)error
{
switch (state) {
case FBSessionStateOpen:
if (!error) {
// We have a valid session
//NSLog(#"User session found");
[FBRequestConnection
startForMeWithCompletionHandler:^(FBRequestConnection *connection,
NSDictionary<FBGraphUser> *user,
NSError *error) {
if (!error) {
self.loggedInUserID = user.id;
self.loggedInSession = FBSession.activeSession;
}
}];
}
break;
case FBSessionStateClosed:
case FBSessionStateClosedLoginFailed:
[FBSession.activeSession closeAndClearTokenInformation];
break;
default:
break;
}
[[NSNotificationCenter defaultCenter]
postNotificationName:FBSessionStateChangedNotification
object:session];
if (error) {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:#"Error"
message:error.localizedDescription
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
}
}
/*
* Opens a Facebook session and optionally shows the login UX.
*/
- (BOOL)openSessionWithAllowLoginUI:(BOOL)allowLoginUI {
return [FBSession openActiveSessionWithReadPermissions:nil
allowLoginUI:allowLoginUI
completionHandler:^(FBSession *session,
FBSessionState state,
NSError *error) {
[self sessionStateChanged:session
state:state
error:error];
}];
}
/*
*
*/
- (void) closeSession {
[FBSession.activeSession closeAndClearTokenInformation];
}
/*
* If we have a valid session at the time of openURL call, we handle
* Facebook transitions by passing the url argument to handleOpenURL
*/
- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation {
// attempt to extract a token from the url
return [FBAppCall handleOpenURL:url sourceApplication:sourceApplication];
}
You need to add the following to the app delegate
- (BOOL)application:(UIApplication *)application
openURL:(NSURL *)url
sourceApplication:(NSString *)sourceApplication
annotation:(id)annotation {
// Call FBAppCall's handleOpenURL:sourceApplication to handle Facebook app responses
BOOL wasHandled = [FBAppCall handleOpenURL:url sourceApplication:sourceApplication];
// You can add your app-specific url handling code here if needed
return wasHandled;
}
You may need to implement the
(BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url method
Be sure to call:
return [FBSession.activeSession handleOpenURL:url];
When applicable.
#Sergey: Are you want to open FBDialog on your native app or in browser? If you to want open in your native app then use "FBSessionLoginBehaviorForcingWebView". Here is my code that I am using:
NSArray *permission = [NSArray arrayWithObjects:kFBEmailPermission,kFBUserPhotosPermission, nil];
FBSession *session = [[FBSession alloc] initWithPermissions:permission];
[FBSession setActiveSession: [[FBSession alloc] initWithPermissions:permission] ];
[[FBSession activeSession] openWithBehavior:FBSessionLoginBehaviorForcingWebView completionHandler:^(FBSession *session, FBSessionState status, NSError *error) {
switch (status) {
case FBSessionStateOpen:
[self yourmethod];
break;
case FBSessionStateClosedLoginFailed: {
// prefer to keep decls near to their use
// unpack the error code and reason in order to compute cancel bool
NSString *errorCode = [[error userInfo] objectForKey:FBErrorLoginFailedOriginalErrorCode];
NSString *errorReason = [[error userInfo] objectForKey:FBErrorLoginFailedReason];
BOOL userDidCancel = !errorCode && (!errorReason || [errorReason isEqualToString:FBErrorLoginFailedReasonInlineCancelledValue]);
if(error.code == 2) {
UIAlertView *errorMessage = [[UIAlertView alloc] initWithTitle:#"FBAlertTitle"
message:#"FBAuthenticationErrorMessage"
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[errorMessage performSelectorOnMainThread:#selector(show) withObject:nil waitUntilDone:YES];
errorMessage = nil;
}
}
break;
// presently extension, log-out and invalidation are being implemented in the Facebook class
default:
break; // so we do nothing in response to those state transitions
}
}];
permission = nil;
or you want to open in browser then use following :
In your .h file
#import <FacebookSDK/FacebookSDK.h> and add FBLoginViewDelegate delegate
In you .m file
FBLoginView *loginview = [[FBLoginView alloc] init];
loginview.frame = CGRectOffset(loginview.frame, 5, 5);
loginview.delegate = self;
[self.view addSubview:loginview];
[loginview sizeToFit];
// use following delegate methods
- (void)loginViewShowingLoggedInUser:(FBLoginView *)loginView {
// first get the buttons set for login mode
}
- (void)loginViewFetchedUserInfo:(FBLoginView *)loginView
user:(id<FBGraphUser>)user {
// here we use helper properties of FBGraphUser to dot-through to first_name and
// id properties of the json response from the server; alternatively we could use
// NSDictionary methods such as objectForKey to get values from the my json object
NSLog(#"userprofile:%#",user);
}
- (void)loginViewShowingLoggedOutUser:(FBLoginView *)loginView {
//BOOL canShareAnyhow = [FBNativeDialogs canPresentShareDialogWithSession:nil];
}
- (void)loginView:(FBLoginView *)loginView handleError:(NSError *)error {
// see https://developers.facebook.com/docs/reference/api/errors/ for general guidance on error handling for Facebook API
// our policy here is to let the login view handle errors, but to log the results
NSLog(#"FBLoginView encountered an error=%#", error);
}
I know this sound a very simple question. I'm still a newbie in iPad app development. Would you please tell me how would I update the contents in the run time. The following code may be helpful to know my question in detail.
In the following code, I'm trying to display text contents in the TexViewcontrol. When I change the for loop form 10 to 100000, I needed to wait until everything fills up. I need to display the contents on the screen while loop is running.
- (IBAction)RunHelloWorld:(id)sender
{
tctView.text = #"tt";
for(int i=0;i<10;i++)
{
NSString *result1 = #"Testing";
tctView.text = [tctView.text stringByAppendingString:result1];
tctView.scrollEnabled = YES;
}
}
Would you please give me any help? Thanks a LOT!!!
-Teva
Finally I found the solution with the following URL's help. http://samplecodebank.blogspot.com/2011/05/nsthread-example_12.html
Thanks a LOT!
This is my code.
PCViewController.h file code
#import <UIKit/UIKit.h>
#interface PCViewController : UIViewController
{
IBOutlet UITextView *txtView;
}
-(void)ReadFile;
- (void) mainThreadSetText:(NSString*)text;
#end
PCViewController.m file code
#import "PCViewController.h"
#interface PCViewController ()
#end
#implementation PCViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[NSThread detachNewThreadSelector:#selector(ReadFile) toTarget:self withObject:nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
-(void)ReadFile
{
// Check whether current thread is externally terminated or not.
char line[1024];
FILE *fp = fopen("/Users/Teva/Desktop/File1.txt","r");
while([[NSThread currentThread] isCancelled] == NO)
{
if( fp != NULL )
{
while( fgets(line,1024,fp) )
{
printf("%s\n",line);
NSString *result1 = [NSString stringWithCString:line encoding:NSASCIIStringEncoding];
[self performSelectorOnMainThread:#selector(mainThreadSetText:) withObject:result1 waitUntilDone:YES];
[NSThread sleepForTimeInterval:1.0];
}
}
}
}
// Screen processing should be done outside the Thread.
- (void) mainThreadSetText:(NSString*)text
{
txtView.text = [txtView.text stringByAppendingString:text];
txtView.scrollEnabled = YES;
}
- (void)dealloc
{
[txtView release];
[super dealloc];
}
#end
Is it possible to play a track when the app has exited/gone into a background state?
For example:
- (void)applicationDidEnterBackground:(UIApplication *)application
{
NSURL *trackURL = [NSURL URLWithString:#"spotify:track:489K1qunRVBm2OpS4XGLNd"];
[[SPSession sharedSession] trackForURL:trackURL callback:^(SPTrack *track) {
if (track != nil) {
[SPAsyncLoading waitUntilLoaded:track timeout:kSPAsyncLoadingDefaultTimeout then:^(NSArray *tracks, NSArray *notLoadedTracks) {
[self.playbackManager playTrack:track callback:^(NSError *error) {
if (error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Cannot Play Track"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
} else {
self.currentTrack = track;
}
}];
}];
}
}];
}
The above code was taken from the Simple Player app provided with cocoalibspotify.
Copying and pasting code like this won't get you far when backgrounding - you can't use UI elements like UIAlertView, for a start.
You need to declare your application as supporting the audio background mode as documented by Apple. Then, when you go into the background you should make a background task to start playback.
I have implemented a UISearchBar into a table view and almost everything is working except one small thing: When I enter text and then press the search button on the keyboard, the keyboard goes away, the search results are the only items shown in the table, the text stays in the UISearchBar, but the cancel button gets disabled.
I have been trying to get my list as close to the functionality of the Apple contacts app and when you press search in that app, it doesn't disable the cancel button.
When I looked in the UISearchBar header file, I noticed a flag for autoDisableCancelButton under the _searchBarFlags struct but it is private.
Is there something that I am missing when I setup the UISearchBar?
I found a solution. You can use this for-loop to loop over the subviews of the search bar and enable it when the search button is pressed on the keyboard.
for (UIView *possibleButton in searchBar.subviews)
{
if ([possibleButton isKindOfClass:[UIButton class]])
{
UIButton *cancelButton = (UIButton*)possibleButton;
cancelButton.enabled = YES;
break;
}
}
I had to tweak this a bit to get it work for me in iOS7
- (void)enableCancelButton:(UISearchBar *)searchBar
{
for (UIView *view in searchBar.subviews)
{
for (id subview in view.subviews)
{
if ( [subview isKindOfClass:[UIButton class]] )
{
[subview setEnabled:YES];
NSLog(#"enableCancelButton");
return;
}
}
}
}
There is two way to achieve this easily
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{
// The small and dirty
[(UIButton*)[searchBar valueForKey:#"_cancelButton"] setEnabled:YES];
// The long and safe
UIButton *cancelButton = [searchBar valueForKey:#"_cancelButton"];
if ([cancelButton respondsToSelector:#selector(setEnabled:)]) {
cancelButton.enabled = YES;
}
}
You should go with the second one, it will not crash your application if Apple will change it in the background.
BTW i tested it from iOS 4.0 to 8.2 and no changes, also i use it in my Store approved application without any issues.
This is what made it to work on iOS 6 for me:
searchBar.showsCancelButton = YES;
searchBar.showsScopeBar = YES;
[searchBar sizeToFit];
[searchBar setShowsCancelButton:YES animated:YES];
Here's my solution, which works for all situations in all versions of iOS.
IE, other solutions don't handle when the keyboard gets dismissed because the user dragged a scroll view.
- (void)enableCancelButton:(UIView *)view {
if ([view isKindOfClass:[UIButton class]]) {
[(UIButton *)view setEnabled:YES];
} else {
for (UIView *subview in view.subviews) {
[self enableCancelButton:subview];
}
}
}
// This will handle whenever the text field is resigned non-programatically
// (IE, because it's set to resign when the scroll view is dragged in your storyboard.)
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar {
[self performSelector:#selector(enableCancelButton:) withObject:searchBar afterDelay:0.001];
}
// Also follow up every [searchBar resignFirstResponder];
// with [self enableCancelButton:searchBar];
As per my answer here, place this in your searchBar delegate:
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
dispatch_async(dispatch_get_main_queue(), ^{
__block __weak void (^weakEnsureCancelButtonRemainsEnabled)(UIView *);
void (^ensureCancelButtonRemainsEnabled)(UIView *);
weakEnsureCancelButtonRemainsEnabled = ensureCancelButtonRemainsEnabled = ^(UIView *view) {
for (UIView *subview in view.subviews) {
if ([subview isKindOfClass:[UIControl class]]) {
[(UIControl *)subview setEnabled:YES];
}
weakEnsureCancelButtonRemainsEnabled(subview);
}
};
ensureCancelButtonRemainsEnabled(searchBar);
});
}
None of the answers worked for me at all. I'm targeting iOS 7. But I found an answer.
What I'm trying is something like the Twitter iOS app. If you click on the magnifying glass in the Timelines tab, the UISearchBar appears with the Cancel button activated, the keyboard showing, and the recent searches screen. Scroll the recent searches screen and it hides the keyboard but it keeps the Cancel button activated.
This is my working code:
UIView *searchBarSubview = self.searchBar.subviews[0];
NSArray *subviewCache = [searchBarSubview valueForKeyPath:#"subviewCache"];
if ([subviewCache[2] respondsToSelector:#selector(setEnabled:)]) {
[subviewCache[2] setValue:#YES forKeyPath:#"enabled"];
}
I arrived at this solution by setting a breakpoint at my table view's scrollViewWillBeginDragging:. I looked into my UISearchBar and bared its subviews. It always has just one, which is of type UIView (my variable searchBarSubview).
Then, that UIView holds an NSArray called subviewCache and I noticed that the last element, which is the third, is of type UINavigationButton, not in the public API. So I set out to use key-value coding instead. I checked if the UINavigationButton responds to setEnabled:, and luckily, it does. So I set the property to #YES. Turns out that that UINavigationButton is the Cancel button.
This is bound to break if Apple decides to change the implementation of a UISearchBar's innards, but what the hell. It works for now.
Here's a Swift 3 solution that makes use of extensions to get the cancel button easily:
extension UISearchBar {
var cancelButton: UIButton? {
for subView1 in subviews {
for subView2 in subView1.subviews {
if let cancelButton = subView2 as? UIButton {
return cancelButton
}
}
}
return nil
}
}
Now for the usage:
class MyTableViewController : UITableViewController, UISearchBarDelegate {
var searchBar = UISearchBar()
func viewDidLoad() {
super.viewDidLoad()
searchBar.delegate = self
tableView.tableHeaderView = searchBar
}
func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
DispatchQueue.main.async {
if let cancelButton = searchBar.cancelButton {
cancelButton.isEnabled = true
cancelButton.isUserInteractionEnabled = true
}
}
}
}
For Monotouch or Xamarin iOS I have the following C# solution working for iOS 7 and iOS 8:
foreach(UIView view in searchBar.Subviews)
{
foreach(var subview in view.Subviews)
{
//Console.WriteLine(subview.GetType());
if(subview.GetType() == typeof(UIButton))
{
if(subview.RespondsToSelector(new Selector("setEnabled:")))
{
UIButton cancelButton = (UIButton)subview;
cancelButton.Enabled = true;
Console.WriteLine("enabledCancelButton");
return;
}
}
}
}
This answer is based on David Douglas solution.
A more complete answer:
since iOS 7, there is an additional level of subviews under the searchBar
a good place to enable the cancel button is in searchBarTextDidEndEditing
.
extension MyController: UISearchBarDelegate {
public func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
DispatchQueue.main.async {
// you need that since the disabling will
// happen after searchBarTextDidEndEditing is called
searchBar.subviews.forEach({ view in
view.subviews.forEach({ subview in
// ios 7+
if let cancelButton = subview as? UIButton {
cancelButton.isEnabled = true
cancelButton.isUserInteractionEnabled = true
return
}
})
// ios 7-
if let cancelButton = subview as? UIButton {
cancelButton.isEnabled = true
cancelButton.isUserInteractionEnabled = true
return
}
})
}
}
}
Time passes, but the problem is still there...
Elegant Swift 5/iOS 13 solution:
func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
for case let cancelButton as UIButton in searchBar.subviews {
cancelButton.isEnabled = true
}
}