CODEWITHSUNDEEP
iphonecaching
Amit Vaghela
Amit Vaghela

Reputation: 2970

Is that possible to cache UIWebView in iPhone?

I was using NYTimes iPhone application, I become bit curious when I notice that it cache UIwebview even though I didn't open that article.Does anyone have idea how to do that?

How NYTimes iPhone application doing offline reading?

Any help greatly appreciated.

Thanks,

Amit

Upvotes: 2

Views: 2352

Answers (2)

Adam Kaplan
Adam Kaplan

Reputation: 1962

I wrote the NYTimes app. Here are some details that you could have gotten by looking inside the app bundle.

I download the HTML for the articles, strip out whatever unsupported HTML and JS crud the producers stuffed in it and cache it in the backing store.

The article content is contained in a series of P tags (HTML fragment). I stuff that into a special HTML skeleton page that ships with the app. The static wrapper page also contains CSS and JS used to properly display the article and lazily load the images.

The image loading is really cool. The web view is notified when the images are ready. layout is not affected because I already know the sizes of the missing images.

Upvotes: 2

bentford
bentford

Reputation: 33406

You can use UIWebView to load html files stored locally on the iPhone.

NYTimes app is probably caching html and images in local storage.

Search google for "UIWebView local" and you get several useful hits.

I tried it out and it works great:

First, create a "view based application" and add a UIWebView to the NIB.

Second, add this code to your UIViewController code:

- (void)viewDidLoad 
{

    NSString *path = [[NSBundle mainBundle] pathForResource:@"index" ofType:@"html"];
    NSURL *url = [NSURL fileURLWithPath:path isDirectory:NO];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    [webView loadRequest:request];


    [super viewDidLoad];
}

Third, add a file called "index.html" to your "Resources" folder in xcode and it will be displayed.

UPDATE:

Indeed, the complicated part of this is downloading the images and stylesheets for the webpage. Doing this server side is easy with Simple HTML Parser (and PHP). Just package everything in a zip and download to your iPhone.

Alternatively, you could do it locally with a C/C++/OBJC HTML parser (libxml2.2 is available on iOS). See this SO question Parsing HTML on the iPhone.

It's going to a bit of a project, so good luck.

Upvotes: 1

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