I have a tab bar controller, one tab screen contains a web view, loading a request say google.com, when it is loading(ie before the didload delegate method call of webview), if I switch to another tab and then go back, the spinner is still running but the page is never loaded, I guess viewDidLoad is only called once, so should I put the loading code in viewDidAppear, or is there anyway to solve this?
Thanks!
I don't understand why you want to refresh the WebView everytime it appears. But use - (void)viewWillAppear:animated
Edit:
OK, since ive got more info now, i can give you more info!
In your .h:
BOOL *loaded
in your .m:
- (void)viewWillAppear:animated {
if (loaded == NO) {
//load the website
}
}
- (void)webViewDidFinishLoad:(UIWebView *)webView {
[loaded setBool:YES];
}
- (IBAction)loadWebsite {
//if the user reloads or loads a new website do this:
[loaded setBool:NO];
//reload, or load the new website
}
To load, or reload your UITableView:
NSString *urlAddress = urltextfield.text;
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];
Clarification: I am setting the BOOL to YES if the View is loaded, so when the webview has finished loading and the user switches to the other tab, and back the WebView doesn't get reloaded. But if the WebView isn't fully loaded the BOOl returns NO, and the WebView will get reloaded! When the WebView gets reloaded or a new Website gets loaded im setting the BOOL to NO, and that loops over and over! Note that BOOls are NO by default.
Related
I am updating my project from UIWebView to WKWebView. In existing UIWebView approach where UIWebView does't have any parent until it runs javascript and once it has content, it adds a parent to the webview. Content renders fine using UIWebView. I am using the same approach for WKWebView, however WKWebview stuck at loading. Is there any way we can execute javascript on wkwebview without adding parent to the webview. Another interesting thing is it works on simulator not on device. Using localHTTPServer to serve the html, css and images.
Any Suggestions or Tips to solve the above issue.
I have observed similar behavior in my app running socket.io in a headless WKWebView. In my case, the web socket would disconnect all the time and not reconnect.
It seems that since WKWebView runs javascript off-process that it will pause any javascript that is considered idle to save resources (<-IMO). Idle includes not having a parent or the app/device is inactive. So, yes, it seems like you are correct in that it needs a parent view in most cases. I was able to work around this using the following code:
WKWebViewConfiguration* webViewConfig = // set up config
// provide empty frame rect
WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectZero configuration:webViewConfig];
// add to keyWindow to ensure it is 'active'
[UIApplication.sharedApplication.keyWindow addSubview:webView];
This approach at least ensures the javascript runs while the app is active and doesn't effect the UI. If you need to display it later you can remove the webView from the keyWindow after render and reset the frame. And, yes, I also observed that in the simulator this is not an issue (javascript ALWAYS runs, regardless of parent or app state)
Hope this helps!
The accepted solution worked for me some of the time. I tried something else which appears to work for me consistently:
self.keepWebViewActiveTimer = [NSTimer scheduledTimerWithTimeInterval:0.2
target:self
selector:#selector(_keepWKWebViewActive:)
userInfo:nil
repeats:YES];
Where _keepWKWebViewActive is:
-(void) _keepWKWebViewActive:(NSTimer*) timer{
if(self.webView) {
[self.webView evaluateJavaScript:#"1+1" completionHandler:nil];
}
}
I have a uiviewcontroller which loads a uiwebview. When the uiviewcontroller loads the uiwebview everything is done correctly. But when one navigates away and returns back and the uiwebview is not loaded, it is displayed differently. The uiwebview scrollview's contentsize height changes by 64px, it gets higher.
When it is loaded for the first it looks like this
When one returns back to the view, this is what happens
I hope I was able to make my problem understandable. If more details are necessary, I am able to give more. Thank you
I had a similar problem, try this code in your viewDidLoad method.
if([self respondsToSelector:#selector(setAutomaticallyAdjustsScrollViewInsets:)])
self.automaticallyAdjustsScrollViewInsets = NO;
You can do like this.
- (void) viewDidLoad
{
[super viewDidLoad];
self.automaticallyAdjustsScrollViewInsets = NO;
}
I have html content which is displayed using UIWebView. User navigate pages using UIPageViewController. The problem is that the web view completes rending the content after the page is displayed. There is noticeable delay makes the performance sluggish.
- (ContentViewController *)viewControllerAtIndex:(NSUInteger)index andPageIndex: (NSUInteger)pageIndex{
if (([self.pageData count] == 0) || (index >= [self.pageData count])) {
return nil;
}
Topic * topic = (Topic *)[pageData objectAtIndex:index];
ContentViewController * contentViewController = [[ContentViewController alloc] init];
[contentViewController setCurrentTopic:topic];
[contentViewController setCurrentPageIndex:pageIndex];
return hadeethViewController;
}
The Content View Controller will not render the content unless it is really loaded by the PageViewContoller. Is there any way to enforce the view to load before the viewControllerAtIndex returns? Or is there any solution for such situation?
UIWebView can load content while not on screen. I'm guessing your issue is that your webview gets initialized only after your ContentViewController has been initialized. If you already know which HTML files will be loaded as your user pages through the content you can preload them as necessary in off-screen UIWebViews before creating the ContentViewController and add the corresponding, pre-loaded UIWebView to the content view controller.
I have a ViewController with a UIWebView, in a Objective-c project for iPad.
When I add html (with loadHtmlString), I try to keep the scroll position it had before the loadHtml, but I cannot help and it returns to the top.
Here are the lines I use:
scrollPosition = [[webView stringByEvaluatingJavaScriptFromString: #"scrollY"] intValue];
[webView loadHTMLString:html baseURL:nil];
[webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"window.scrollTo(0, %d);",scrollPosition]];
I tested the value 'scrollY' at different locations in my code
and it stays at the value scrollPosition that I want, but when it ends up showing on the screen the WebView is always at the top (with the scrollY value then to 0).
Is there someone who could help me figure out why this happens?
I checked for hours the answers online, also on StackOverflow.
I tried different solutions (like adding in my webview the JavaScript "onclick="scroll(); return false;", but to no avail.
I tried to self-delegate the webView and update the scrollTo in webViewDidFinishLoad, but it seems that webViewDidFinishLoad is not called (the breakpoint is not reached) although I did add in .h in the interface and in the .m in ViewDidLoad the line: webView.delegate=self;
Thank you in advance for any help.
I realized that after recompiling, webViewDidFinishLoad was called after the html was updated, and that I could then scroll to the correct position.
For the self delegation I used in viewDidLoad, it looks so:
webview.delegate = self;
Before updating the html in the webView I calculate the scrolling position with the code:
scrollPosition = [[wbView stringByEvaluatingJavaScriptFromString: #"scrollY"] intValue];
Then, for moving back to this position once the webView has an updated html, I then use:
-(void) webViewDidFinishLoad:(UIWebView *)wbView {
[wbView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:#"window.scrollTo(0, %d);",scrollPosition]];
}
I found part of the solution through the post below, with the answer of Pawel:
How can I scroll programmatically to the bottom in a uiwebview
In my windows based applicaton, after login screen and registration page I added navigation controller for next two views. After pressing button present on second navigation window,again i want normal view controller and not navigation. But Its giving me navigation window with back button which takes me to second navigation window.
Can anyone plz tell me the solution??
You have a couple choices: you can truly eliminate the Navigation Controller entirely and replace it with another UIViewController (more complicated), or you can just push a new UIViewController that will not have a navigation bar/back button, and use that as the effective "root" view controller of your application from there on out. Without the navigation bar, your view controller will look like a "normal" view controller.
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationController.navigationBar.hidden = YES;
...
}