I have web page having 1000's of images and values. Whenever I load the page to UIWebView it gets loaded with values but as there are so many images it takes time to download.
So is there any way, I can download the page from web but images from local.
Any help is really appreciated.
Thank you,
Ankita
If you have your HTML from webserver and images at local
yourBaseURL = [[NSURL alloc] initFileURLWithPath:[[NSBundle mainBundle] bundlePath]];
[webView loadHTMLString:#"YourHTML" baseURL:yourBaseURL]
and your HTML contains name of local image stored like
Image Tag like --> imgage src='fig1.jpg width=150 height=150 align="left"
Than this should work.
Not exactly as you required though this way you can load local images in webView.
Basically:
Download HTML from server.
NSURL *URL = [[NSURL alloc] initWithString:#"http://www.example.com/page.php"];
NSError *error = nil;
NSStringEncoding encoding;
NSString *theSource = [[NSString alloc] initWithContentsOfURL:URL usedEncoding:&encoding error:&error];
Replace the file references to load images locally.
Note the double slashes, this seems important.
// Replace:
<img src="File.png">
// By something like:
<img src="file://Path//To//Resources//File.png">
Detailed information how to do this (check post by Joe D'Andrea):
Link to resources inside WebView - iPhone
Finally make the UIWebView load the HTML:
[webView loadHTMLString:htmlString baseURL:baseURL];
Now it should load the 'fresh' HTML from the server with local images.
This works quite well for me.
NSURL *myBaseURL = [[NSURL alloc] initFileURLWithPath:[[NSBundle mainBundle] bundlePath]];
NSString *myString = [[managedObject valueForKey:#"long_presentation"] stringByReplacingOccurrencesOfString:#"/FooFolder/BarFolder" withString:[NSString stringWithFormat:#"%#/FooFolder/BarFolder", [[NSBundle mainBundle] bundlePath] ] ];
[attractionWebView loadHTMLString:myString baseURL:myBaseURL];
I had to include a replacement for the image source
img src="FooFolder/BarFolder/my_image.jpg" ...
to get the right path.
Related
I am trying to load a UIWebView with local HTML/CSS that is build to look like a nutrition label. The problem is, the data for the food lies inside of my iPhone app. Do I have to put all of my HTML into one enormous NSString object and concatenate my data into it, or is there a way to load the HTML from a local .html file, but somehow "inject" the data that is stored within Objective-C into it?
If the data to be injected is "safe", you could construct your "enormous NSString object" as a format string, sprinkled with %# markers, and use stringWithFormat: to perform the injection in a single move. This is how I construct the pages in the TidBITS News app, using pieces that all come from RSS. It's really quite painless.
You can load basic html using NSData's method dataWithContentsOfFile and then use javascript to modify html in the way you need.
Code would look something like this (using this example):
NSString *path = [[NSBundle mainBundle] pathForResource:#"food" ofType:#"html"];
NSData *data = [NSData dataWithContentsOfFile:path];
if (data) {
[webView loadData:data MIMEType:#"text/html" textEncodingName:#"UTF-8"];
}
[webView stringByEvaluatingJavaScriptFromString:#"var script = document.createElement('script');"
"script.type = 'text/javascript';"
"script.text = \"function myFunction() { "
"var field = document.getElementById('field_3');"
"field.value='Calling function - OK';"
"}\";"
"document.getElementsByTagName('head')[0].appendChild(script);"];
[webView stringByEvaluatingJavaScriptFromString:#"myFunction();"];
I would do a hybrid of both- have an HTML file in the app that you load, then replace certain strings in that before giving it to the UIWebView. So for example, you could have a file like this
<html>
<head>
<title><!--foodName--></title>
</head>
<body>
<h1><!--foodName--></h1>
<p>Calories / 100g: <!--foodCalories--></p>
</body>
</html>
You'd load that into Cocoa, then replace your special placeholder comments with the actual values you want.
NSDictionary *substitutions = [NSDictionary dictionaryWithObjectsAndKeys:
#"Carrots", #"foodName",
[NSNumber numberWithInt:20], #"foodCalories",
// add more as needed
nil];
NSMutableString *html = [NSMutableString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"foodCard" ofType:#"html"]
encoding:NSUTF8StringEncoding
error:nil];
for(NSString *substitutionKey in substitutions)
{
NSString *substitution = [[substitution objectForKey:substitutionKey] description];
NSString *searchTerm = [NSString stringWithFormat:#"<!--%#-->", substitutionKey];
[html replaceOccurrencesOfString:searchTerm withString:substitution options:0 range:NSMakeRange(0, [html length])];
}
[webView loadHTMLString:html baseURL:[[NSBundle mainBundle] resourceURL]];
Since iOS 2 you can use - (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script within a UIWebView subclass to execute JS scripts in your webview. This is the best way to inject data from the "Objective-C part" of your application.
Cf: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIWebView_Class/#//apple_ref/occ/instm/UIWebView/stringByEvaluatingJavaScriptFromString:
I new to iOS programming and tried to figure out what loadHTMLString:baseURL: really does, but I can't find a satisfying explanation. The site of Apple just says:
Sets the main page content and base URL.
Can someone please explain this in a more detailed way to me?
I am pretty certain that the baseURL is used just like in regular web pages to properly load ressources that are referenced using relative links. Now the question is, how to set that base URL to a particular folder in the app directory.
This is how mainly content is loaded in a webView. either from a local html file or through a url.
//this is to load local html file. Read the file & give the file contents to webview.
[webView loadHTMLString:someHTMLstring baseURL:[NSURL URLWithString:#""]];
//if webview loads content through a url then
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://google.com"]]]
- (void) loadHTMLString:(NSString *)string baseURL:(nullable NSURL *)baseURL;
is used to load local HTML file, parameter string means content of html file, if your HTML file contains some href tag with relative path, you should set the parameter baseUrl with the base address of the HTML file, or set it nil.
NSString *cachePath = [self cachePath];
NSString *indexHTMLPath = [NSString stringWithFormat:#"%#/index.html", cachePath];
if ([self fileIsExsit:indexHTMLPath]) {
NSString *htmlCont = [NSString stringWithContentsOfFile:indexHTMLPath
encoding:NSUTF8StringEncoding
error:nil];
NSURL *baseURL = [NSURL fileURLWithPath:cachePath];
[self.webView loadHTMLString:htmlCont baseURL:baseURL];
}
- (NSString *)cachePath
{
NSArray* cachePath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
return [cachePath[0] stringByAppendingPathComponent:#"movie"];
}
How can I have a local image loaded into a html page in a UIWebView that is called with
[self.webView loadHTMLString:htmlSourceCode baseURL:externPageUrl];
I know I can get the image by changing the baseURL. However, in my case, that is not possible.
I also tried doing it by adding file://pathToImage/myimage.png to the html, but that doesn't work without changing the baseURL.
Is there any way without having to handle the shouldStartLoadWithRequest method?
Just set the image src to the name of the image file, assuming it is in the same folder as the local HTML file.
I solved it by loading the image bytes into the html directly:
//retrieve image data, to embedd into the html as base64
NSURL *imgURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"myImage" ofType:#"png"] isDirectory:NO];
NSData *data = [NSData dataWithContentsOfURL:imgURL];
[htmlContent appendFormat:#"<div class=\"myCssClass\" style=\"background:url(data:image/png;base64,%#) no-repeat center center;\" ></div>",
[data encodeBase64] ];
I've got some HTML and some images in my iPhone app, arranged something like:
html/
foo.html
images/
bar.png
I can get bar.png to appear in my UIWebView a couple of different ways -- either loading foo.html from an NSUrl, and walking back up the directory tree from the html directory:
<img src="../images/bar.png"/>
or by loading foo.html into a string, using loadHtmlString, and using [[NSBundle mainBundle] bundleURL] as the baseURL:
<img src="images/bar.png"/>
Both of these are kind of clumsy, though -- in the first case, if I move HTML files around I have to rejigger all the relative paths, and in the second case, I have to ignore the actual path structure of the HTML files.
What I'd like to make work is this --
<img src="/images/bar.png"/>
-- treating the bundleURL as the root of the "site". Is there any way to make this work, or am I doomed to have that translated into file:///images/bar.png and have the file not found?
Only way I can see for you to do this would be to embed a web server in your app. Matt Gallagher has a blog post on this you could start from. Alternatively, CocoaHTTPServer and Mongoose could be dropped into your project.
If I'm not mistaken, you have some files in your project bundle that you want to load in your web view. You can do it simply with these few lines of code:
NSString *imagePath = [[NSBundle mainBundle] pathForResource:#"bar" ofType:#"png"];
NSURL *imageURL = [NSURL fileURLWithPath:imagePath];
I'm assuming that you have a text/html file containing the pattern for your web view. You'll need to add the image as an object there (src="%#"...) and then add the imageURL to the pattern:
NSString *path = [[NSString alloc]initWithString:[[NSBundle mainBundle]pathForResource:#"htmlPattern" ofType:#"html"]];
NSError *error;
NSString *pattern = [[NSString alloc]initWithContentsOfFile:path
encoding:NSUTF8StringEncoding
error:&error];
htmlPage = [[NSString alloc]initWithFormat:pattern,
imageURL;
webView = [[UIWebView alloc] initWithFrame:WEBVIEW_FRAME];
[webView loadHTMLString:htmlPage baseURL:[NSURL URLWithString:path]];
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:pattern]]];
I have downloaded a gif image into an NSData object (I've checked the contents of the NSData object and it's definitely populated). Now I want to load that image into my UIWebView. I've tried the following:
[webView loadData:imageData MIMEType:#"image/gif" textEncodingName:nil baseURL:nil];
but I get a blank UIWebView. Loading the image from the same URL directly works fine:
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:imageUrl]];
[imageView loadRequest:request];
Do I need to set the textEncodingName to something, or am I doing something else wrong?
I want to load the image manually so I can report progress to the user, but it's an animated gif, so when it's done I want to show it in a UIWebView.
Edit: Perhaps I need to wrap my image in HTML somehow? Is there a way to do this without having to save it to disk?
I tested the code with PNG ("image/png"), JPG ("image/jpeg") and GIF ("image/gif"), and it works as expected:
[webView loadData:imageData MIMEType:imageMIMEType textEncodingName:nil baseURL:nil];
Now, what's wrong with your app?
the imageData is not a well-formed image data. Try opening the file with a web browser or an image editor to check it.
the MIME type is incorrect. Look at the first bytes of the data to determine the actual file type.
webView is not connected in IB, is nil, is hidden, is covered with another view, is off screen, has a CGRectZero frame, etc.
I did not really try to load image to UIWebView but a google search gives me. I think your image string must have a good path and looks like a URL
NSString *imagePath = [[NSBundle mainBundle] resourcePath];
imagePath = [imagePath stringByReplacingOccurrencesOfString:#"/" withString:#"//"];
imagePath = [imagePath stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
NSString *HTMLData = #"
<h1>Hello this is a test</h1>
<img src="sample.jpg" alt="" width="100" height="100" />";
[webView loadHTMLString:HTMLData baseURL:[NSURL URLWithString: [NSString stringWithFormat:#"file:/%#//",imagePath]]];
You can see more details here : Loading local files to UIWebView
UIImage *screenshot= [UIImage imageAtPath:
[[NSBundle mainBundle] pathForResource:#"MfLogo_aboutus" ofType:#"png"]];
NSData *myData = UIImagePNGRepresentation(screenshot);
[vc addAttachmentData:myData mimeType:#"image/png" fileName:#"logo.png"];
You can load urlImage into webview which is not saved locally as shown below code
NSString *str = #"";
str = [str stringByAppendingString:#"http://t3.gstatic.com/images?q=tbn:7agzdcFyZ715EM:http://files.walerian.info/Funny/Animals/funny-pictures-firefox-file-transfer-is-complete.jpg"];
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:str]];
[webView loadData:data MIMEType:#"application/jpg" textEncodingName:#"UTF-8" baseURL:[NSURL URLWithString:#"http://google.com"]];
I had the same problem and I found somewhere else that you have to provide a value in the baseURL parameter. I also had encoding set:
textEncodingName:#"UTF-8" baseURL:[NSURL URLWithString:#"http://localhost/"]];
When I had nil in the baseURL parameter it would not load. By putting something that's basically irrelevant in there the MS docs all worked.
You may want to try assigning a delegate to the webview and implementing the method:
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
To see more specifically what error you're getting. If it doesn't get called, implement the method:
- (void)webViewDidFinishLoad:(UIWebView *)webView
as well, just to make sure something is happening, otherwise there might be an issue with UIWebView (assuming you haven't returned NO from webView:shouldStartLoadWithRequest:navigationType:)
To expand on Ed Marty's comment:
The HTML command to put in a base 64 image is:
<img src="data:image/png;base64,##PUT THE BASE64 DATA HERE###" />
I have a category (I'm not sure where it came from, not me...) available on my website that converts NSData to it's Base64 string representation.
Header
Implementation
Easy enough to do, assuming 'imageData' is the NSData variable containing your image:
[imageData base64Encoding] into the above string.
try this code
// 1) Get: Get string from “outline.plist” in the “DrillDownSave”-codesample.
savedUrlString = [item objectForKey: #"itemUrl"];
// 2) Set: The url in string-format, excluding the html-appendix.
NSString *tempUrlString = savedUrlString;
// 3) Set: Format a url-string correctly. The html-file is located locally.
NSString *htmlFile = [[NSBundle mainBundle] pathForResource:tempUrlString ofType:#”html”];
// 4) Set: Set an “NSData”-object of the url-sting.
NSData *htmlData = [NSData dataWithContentsOfFile:htmlFile];
// 5. Gets the path to the main bundle root folder
NSString *imagePath = [[NSBundle mainBundle] resourcePath];
// 6. Need to be double-slashes to work correctly with UIWebView, so change all “/” to “//”
imagePath = [imagePath stringByReplacingOccurrencesOfString:#"/" withString:#"//"];
// 7. Also need to replace all spaces with “%20″
imagePath = [imagePath stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
// Load: Loads the local html-page.
[webView loadData:htmlData MIMEType:#"text/html" textEncodingName:#"UTF-8" baseURL:[NSURL URLWithString:[NSString stringWithFormat:#"file:/%#//",imagePath]]];
Here's an alternative method:
Save the image you downloaded into your documents folder.
Then get that image's url. Then write a simple html file
using that image url in the IMG SRC tag.
NSLog(#"url=%#", fileURL); // fileURL is the image url in doc folder of your app
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the documents directory:
NSString *fileName = [NSString stringWithFormat:#"%#/toOpen.html",
documentsDirectory];
//create simple html file and format the url into the IMG SRC tag
NSString *content = [NSString stringWithFormat:#"<html><body><img src=%#></body></html>",fileURL];
//save content to the documents directory
[content writeToFile:fileName
atomically:NO
encoding:NSStringEncodingConversionAllowLossy
error:nil]; // now we have a HTML file in our doc
// open the HTML file we wrote in the webview
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"life.html"];
NSURL *url = [NSURL fileURLWithPath:filePath];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[yourWebView loadRequest:request];
NSString *pathForFile = [[NSBundle mainBundle] pathForResource: #"fireballscopy" ofType: #"gif"];
NSData *dataOfGif = [NSData dataWithContentsOfFile: pathForFile];
[Web_View loadData:dataOfGif MIMEType:#"image/gif" textEncodingName:nil baseURL:nil];