I want to load a web site on a UIWebView which is not under my control and edit/add certain UI changes (Some texts, images, etc) to it. Can I do this within my iOS source code? I can't change the hosted html contents since them not under my control.
If this cannot doable within iOS source code, please advice me the correct way to achieve this.
Load the webpage into an NSString, make any modifications and then put the html into the UIWebView.
NSURL *url = [NSURL URLWithString:#"http://example.com/"];
NSString *page = [NSString stringWithContentsOfURL:url usedEncoding:nil error:nil];
/* Make changes to page here */
[self.webView loadHTMLString:page baseURL:nil];
I'd get the dom with JavaScript, manipulate, then inject back with JavaScript.
See stringByEvaluatingJavaScriptFromString:.
You can write your own full featured, minified JavaScript, then pass into using this method.
// Change body color of any HTML content inside a UIWebView.
NSString *javaScript = #"document.getElementByTagName('body').backgroundColor = '#888';";
[webView stringByEvaluatingJavaScriptFromString:javaScript];
Related
I want to open .csv link in the UIWebView. I am getting link some .csv links from the web how to open that link in the UIWebView. I am using the below code
NSString *urlString = #"https://xoxoengage-images-test.s3.amazonaws.com/image/clients/gxoxo/annoucement/XXXXdetails201805021526899124.csv";
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];//[NSURL URLWithString:urlString];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
[_webviewobj loadRequest:urlRequest];
but the result is shown in the below image, help me out to sort this issue.
The UIWebView doesn't support the CSV format natively.
See this: File Formats Supported by UIWebView
If your server returns "text/plain" (or you have this file as ".txt") you'll see its raw text in the web view.
If you want a grid table view, then you need to convert csv to to one of the supported formats. The obvious choice would be HTML.
If you can convert on the server side - that's better, otherwise download the csv file, parse it line by line, and output as HTML. Load the HTML into the web view. loadHTMLString is what you could use.
Also with UIWebView this can be done sort of transparently using a custom NSURLProtocol.
This might be helpful: Where can I find a CSV to NSArray parser for Objective-C?
I'm trying to build an iOS app like Pocket or Instapaper for practice. So, I need to fetch data from a url and strip the HTML of of it. I created the code below to do this.
NSURL *url = [NSURL URLWithString:self.link];
NSString *webData= [NSString stringWithContentsOfURL:url];
NSLog(#"webData is: %#", webData);
NSString *finalhtmlstring = [NSString stringWithFormat:#"%#", webData];
finalhtmlstring = [finalhtmlstring stringByConvertingHTMLToPlainText];
NSLog(#"FinalHTMLString is: %#", finalhtmlstring);
How would I fetch the body of the page? I can't get the NSString between #"<body>" and #"</body>", because some websites add attributes to the <body> tag.
It sounds like parsing XML or HTML page.
Fortunately, there is open-source libraries likes Hpple can help you to get the contents from wrappers easily.
It wraps libxml2 nicely using Objective-C objects
Here is a tutorial about how to use this library.
I'm trying to show a UIWebView with a GIF in it, but only once the GIF has loaded.
I load the GIF as follows:
self.GIFWebView = [[UIWebView alloc] init];
self.GIFWebView.delegate = self;
NSString *html = [NSString stringWithFormat:#"<html><head></head><body><img src=\"%#\"></body></html>", post.url];
[self.GIFWebView loadHTMLString:html baseURL:nil];
Where post is just an object with some properties such as the URL for the GIF.
Then in webViewDidFinishLoad: I show the web view:
- (void)webViewDidFinishLoad:(UIWebView *)webView {
NSLog(#"%f", webView.scrollView.frame.size.width);
NSLog(#"%#", [webView.request.URL absoluteString]);
}
I get "0" and "about:blank" for the NSLogs each time, however.
Why does it not load the GIF properly?
I get "0" and "about:blank" for the NSLogs each time, however.
Not surprising. You're telling the web view to load HTML that you're providing in a string rather than giving it a request. The URL that you're logging is the request URL, and since there's no request, there's no request URL.
Why does it not load the GIF properly?
Possibly because you're misusing the URL object. Look at the code:
NSString *html = [NSString stringWithFormat:#"<html><head></head><body><img src=\"%#\"></body></html>", post.url];
We can't tell what type post.url is, but it's probably NSURL*. You're probably passing a NSURL into the format string, and that may not produce the result you're looking for. Try passing in a string like [post.url absoluteString] instead of the actual NSURL object.
Also, you might want to log the value of html right after you create it so that you can check the full HTML that you're sending to the web view.
Update: Some additional things to check:
Are you running the code in question on the main thread?
Is the thread's run loop getting time?
Have you tried setting a non-nil base URL?
If the web view's delegate has a -webView:shouldStartLoadWithRequest: method, does it return YES?
What happens if you use a constant string that includes the HTML you want and the hard-coded URL instead of constructing the string with +stringWithFormat:?
Is the test device connected to the network? (Sometimes it's the simplest thing that gets you.)
Does it work correctly if you use a different image? I notice that the URL you're using is for an animated .gif file, try a non-animated .gif or a .jpg image instead.
Update 2: The problem lies in your creation of the web view. Look at the very first line in the code that you showed:
self.GIFWebView = [[UIWebView alloc] init];
That looks okay for a typical object, but -init is not the designated initializer for a view. You should use -initWithFrame: instead. The image loads fine in your sample project when I change the code in your project to use the right initializer:
UIWebView *GIFWebView = [[UIWebView alloc] initWithFrame:self.view.bounds];
I want to get URLs of all images or lets say "JPEG" files in a web directory (www.abcde.com/images). I just want their URLs in an array.. I couldnt manage that. Could u pls help me with this?
Thanks in advance..
Assuming you have access to an index file you could simply load via NSURL the whole html file and cut out the link lines. This however will not work (or hardly work) when you want to search ("spider or crawl") for links in more complex documents. On iOS i would suggest you use the simple, yet quite powerfull "hpple" framework (https://github.com/topfunky/hpple). It is used to parse html. You can search with it for certain html elements, such as <a href...> constructs.
a sample with hpple could looks like this:
NSURL *url = [NSURL URLWithString:#"whatver.com/images"];
NSData *data = [NSData url];
TFHpple *hppleParser = [TFHpple data];
NSString *images = #"//img"; // grabbs all image tags
NSArray *node = [hppleParser searchWithXPathQuery:images]
find a bigger example at http://www.raywenderlich.com/14172/how-to-parse-html-on-ios
Create a server side script(eg php) which gives you a list of all images in that directory as xml or json. From iOS send a request to that script get the xml or JSON parse it and use the image urls.
Is there any way to refresh only part of an HTML file displayed in a UIWebView? For example, if I make changes to a div in the body, is there any way to refresh only the contents of that div tag? Or do I have to reload the entire file into my UIWebView?
You have to reload entire HTML file. It is not possible to reload only part of pure HTML file.
Using a little bit of javascript?
use javascript like this
NSString *js = [NSString stringWithFormat:#"document.getElementById('foo').innerHTML ='update';"];
NSString *res = [self stringByEvaluatingJavaScriptFromString:js];