Loading Request in Webview
To load a request you can use the below methods.
1. requestWithURL is used to load a URL in Webview
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NSMutableURLRequest * request =[NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]];
[webview loadRequest:request];
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2. loadHTMLString is used load HTML string in UIWebView
You can use the below code to load HTML string in webview
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NSString * string = @"<html><body><h1>Hayageek</h1>How to <a href=\"/add-custom-fonts-ios/\">Add Custom Font</a>";
[webview loadHTMLString:string baseURL:[NSURL URLWithString:@"http://hayageek.com"]];
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3. loadData method is used to Load NSData in webview. Documents like .doc,.pdf,.xls,.txt,…etc are opened with UIWebview.
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| NSString * path =[[NSBundle mainBundle] pathForResource:@"Resume" ofType:@"doc"];
NSData *data =[[NSFileManager defaultManager] contentsAtPath:path];
[webview loadData:data MIMEType:@"application/msword" textEncodingName:@"UTF-8"baseURL:nil]; |
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To get the list of MIME types:
http://webdesign.about.com/od/multimedia/a/mime-types-by-content-type.htm
UIWebViewDelegate methods.
In order to get
UIWebViewDelegate callbacks, you need to add UIWebViewDelegate protocol to your class and set the webview delegate class.
ViewController.h Source:
@interface ViewController : UIViewController<UIWebViewDelegate>{
}
@property (weak, nonatomic) IBOutlet UIWebView *webview;
@end
ViewController.m Source:
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[webview setDelegate:self];
}
@end
UIWebViewDelegate has the following delegate methods.
webView:shouldStartLoadWithRequest:navigationType: method is called before loading a frame. If the method returns YES, request is loaded. Otherwise NO.
Using this method, requests can be filtered.
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSLog(@"Loading URL :%@",request.URL.absoluteString);
//return FALSE; //to stop loading
return YES;
}
Filtering Clicks, Form Submission,Ads:
//To avoid link clicking.
if(navigationType ==UIWebViewNavigationTypeLinkClicked)
return NO;
//To avoid form submission.
if(navigationType ==UIWebViewNavigationTypeFormSubmitted)
return NO;
//To avoid loading all the google ads.
if([request.URL.absoluteString rangeOfString:@"googleads"].location != NSNotFound)
return NO;
webViewDidStartLoad method is called when a frame starts loading.
- (void)webViewDidStartLoad:(UIWebView *)webView
{
}
webViewDidFinishLoad method is called when a frame finishes loading.
- (void)webViewDidStartLoad:(UIWebView *)webView
{
}
webView:didFailLoadWithError: method is called if frame loading is failed.
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
NSLog(@"Failed to load with error :%@",[error debugDescription]);
}
Execute JavaScript in UIWebview.
You can execute javascript programmatically in WebView using the method
stringByEvaluatingJavaScriptFromString.
Examples:
//Show Cookie as alert in WebView
[webview stringByEvaluatingJavaScriptFromString:@"alert(document.cookie)"];
//Get Cookie
NSString * cookie=[webview stringByEvaluatingJavaScriptFromString:@"document.cookie"];
NSLog(@"cookie =%@",cookie);
//Get sum of 2+3
NSString * result1 =[webview stringByEvaluatingJavaScriptFromString:@"2+3"];
NSLog(@"2+3:%ld",(long)[result1 integerValue]);
//Redirect the current page in WebView
[webview stringByEvaluatingJavaScriptFromString:@"location.href=\"http://apple.com\""];
4).How to add a UIWebview to View Programmatically
UIWebview is added to a View programmatically using the below code.
- (void)viewDidLoad
{
[super viewDidLoad];
//set desired width and height
UIWebView *myWebView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 100, 300, 300)];
[myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]]];
[self.view addSubview:myWebView];
}
