Hey guys, I am working on an application that initially loads a website from the URL http://en.m.wikipedia.org/wiki/::Random? which gives me a random wikipedia page. I was wondering how would I go about parsing the URL to get the actual page label? Like I know that the page for the United States is http://en.m.wikipedia.org/wiki/United_States and Mighty Morphin Power Rangers (the original of course) is http://en.m.wikipedia.org/wiki/Mighty_Morphin_Power_Rangers
How do I go about dealing with the multiple underscores (a random variable) in the URL?
So in the case of your Wikipedia URL, you can use the lastComponent method of NSURL combined with some NSString replacement. Here's an example:
NSURL *url = [NSURL URLWithString:#"http://en.wikipedia.org/wiki/United_Kingdom"];
NSString *title = [url lastPathComponent];
title = [title stringByReplacingOccurrencesOfString:#"_" withString:#" "];
So what happens is you create a NSURL, you ask it for the last component which is returned as a string ("United_Kingdom"), and then you replace all underscores in the string with spaces (giving you "United Kingdom").
Related
I'm using JSON web service to collect data and display in my UITableView cell. My problem is when I try to call my web service, if the data has characters like & it gives me &.
When I try to store this JSON data in NSDictionary and after that display in UITableView cell it appear as it is.
Eg. if data is Chris & Priscilla originally it retrieves as Chris & Priscilla and same shows in my cell. I want to display it as Chris & Priscilla and not Chris & Priscilla.
It displays properly in browser.
I can't find what I missed.
NSError *error = nil;
NSString *strUrl = #"MY-WEBSERVICE-URL";
NSURL *url = [[NSURL alloc] initWithString:strUrl];
NSString *returnText = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
txt.text = returnText;
Usually HTML unescaping is done adding a category to NSString. There are many examples, i.e. here: http://google-toolbox-for-mac.googlecode.com/svn/trunk/Foundation/GTMNSString+HTML.h.
Particularly, have a look at
(NSString *)gtm_stringByUnescapingFromHTML;
In order to obtain URL, I usually follow this way.
NSString *userText = urlText.text;
NSURL *url = [NSURL URLWithString:userText];
Of coursely, urlText is linked with UITextField.
However, Recently, I saw this code in audioStreaming program.
(This is the program.)
NSString *escapedValue =
[(NSString *)CFURLCreateStringByAddingPercentEscapes(nil, (CFStringRef)downloadSourceField.text, NULL, NULL,
kCFStringEncodingUTF8) autorelease];
NSURL *url = [NSURL URLWithString:escapedValue];
downloadSourceField is linked with UITextField.
What is diffence between these two methodes?
When I replaced the second method (escapedValue = ~~~ ) with (escapedValue = downloadSourceField.text;), the program worked well.
Could you let me know what is difference?
And What is the best method to obtain URL for streaming?
The second method will percent-escape some characters which are typically not allowed in URLs. As an example, the space character is not allowed and will be encoded as %20. NSURL does not support passing a string containing a non-allowed character which has not been escaped to +URLWithString:, therefore passing the string through CFURLCreateStringByAddingPercentEscapes first will let you support such URLs.
interesting,
however, digging in the NSString docs you find these two functions:
- (NSString *)stringByReplacingPercentEscapesUsingEncoding:(NSStringEncoding)encoding
- (NSString *)stringByAddingPercentEscapesUsingEncoding:(NSStringEncoding)encoding
I think those are the "official" way of doing this
i have web site that show a text and i update this text every day , i want to show this text on iphone application , how can i get this text from web site from application ?
what should i do ?
thanks
1-> you require to connect with your web server thought HTTP connection.
2-> Make the request to server.
3-> Parse server response that may contain your "Text".
For technical assistance Read below.
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSURLConnection_Class/Reference/Reference.html
I don't recommend this as the best way to obtain a string from your own web server.
This should point you in the right direction, don't expect it to compile cleanly.
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
/* set headers, etc. on request if needed */
[request setURL:[NSURL URLWithString:#"http://example.com/whatever"]];
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:NULL error:NULL];
NSString *html = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
NSScanner *scanner = [NSScanner scannerWithString:html];
NSString *token = nil;
[scanner scanUpToString:#"<h1>" intoString:NULL];
[scanner scanUpToString:#"</h1>" intoString:&token];
This will capture text from first h1 tag.
The simplest way is to create a REST API. That might sound tough but it's really easy. On the server side, create a new page which holds only the raw text. Usually it's best to keep it there in JSON/XML format, but a simple text will also work. Now from the iPhone, just contact that address and the response data will contain the text. Parsing an existing page is not something I recommend, because changing that page in the future might result in the app not working anymore.
This is a answer quite late but I think it still might help in your future. You can go into parsing the website and that is the right way to do it but I will show you how to do it a different way, this can also be used to read xml, html, .com, anything and also, .rss so it can read RSS Feeds.
Here :
This can get your first paragraph, if you request I will show you how to get the second paragraph and so on.
//This is your URL
NSURL *URL = [NSURL URLWithString:#"URL HERE"];
//This is the data your pulling (dont change)
NSData *data = [NSData dataWithContentsOfURL:URL];
// Assuming data is in UTF8. (dont change)
NSString *string = [NSString stringWithUTF8String:[data bytes]];
//Your textView your not done.
description.text = string;
//Do this with your textview
NSString *webStringz = description.text;
// Leave this
NSString *mastaString;
mastaString = webStringz;
{
NSString *webString2222 = mastaString;
NSScanner *stringScanner2222 = [NSScanner scannerWithString:webString2222];
NSString *content2222 = [[NSString alloc] init];
//Change <p> to suit your need like <description> or <h1>
[stringScanner2222 scanUpToString:#"<p>" intoString:Nil];
[stringScanner2222 scanUpToString:#"." intoString:&content2222];
NSString *filteredTitle = [content2222 stringByReplacingOccurrencesOfString:#"<p>" withString:#""];
description.text = filteredTitle;
}
Title ? Same deal change the <p> to a <title> in RSS <description> and <title>.
Image ? Same deal change the <p> to what ever your RSS or website uses to get a image to find
But remember for both of them when you change the` you see the link which says stringByReplacingOccurences of you have to change that as well.
out then you have to delete this and make your code like this :
/This is your URL
NSURL *URL = [NSURL URLWithString:#"URL HERE"];
//This is the data your pulling (dont change)
NSData *data = [NSData dataWithContentsOfURL:URL];
// Assuming data is in UTF8. (dont change)
NSString *string = [NSString stringWithUTF8String:[data bytes]];
//Your textView your not done.
description.text = string;
NLog(#"%#", string)
//Do this with your textview
NSString *webStringz = description.text;
// Leave this
NSString *mastaString;
mastaString = webStringz;
Now check your log it shows your whole website html or rss code then you scroll and read it and find your image link and check the code before it and change the String Scanner to your needs which is quite awesome and you have to change the stringByReplacingOccurences of.
Like I said images are a bit tricky when you do it with this method but XML Parsing is a lot easier ONCE you learn it , lol. If you request I will show you how to do it.
Make sure :
If you want me to show you how to do it in XML just comment.
If you want me to show you how to find the second paragraph or image or title or something just comment.
IF YOU NEED ANYTHING JUST COMMENT.
Bye have fun with code I provided, anything wrong JUST COMMENT! !!!!
:D
I am developing Twitter API to my application. In my app, I want to display the tiny url with parsed xml link in UITexField as dynamically. statically, I could able to display tiny url in UITextField, but dynamically I am not able to display the tiny url. Please help me!
Code: statically(Working fine),
NSURL *url = [NSURL URLWithString"http://tinyurl.com/api-create.php?
url=https://gifts.development.xxxxx.edu/xxxx/Welcome.aspx?appealcode=23430"];
NSString *link = [NSString stringWithContentsOfURL:url encoding:NSASCIIStringEncoding error:nil];
Dynamically,
NSString * tiny = [NSString stringWithFormat:#"http://tinyurl.com/api-create.php? url=%#", shtUrl];//shtUrl is parsed string
NSURL *url = [NSURL URLWithString:tiny];
NSString *link = [NSString stringWithContentsOfURL:url encoding:NSASCIIStringEncoding error:nil];
In above, dynamically app running without warning and error, but url not displayed and when I am checking debugger, url and link both are show nil value. But shtUrl show whole url value as properly.
I tried with all NSURL class and instance methods and String methods also.
In this line of your code:
NSString * tiny = [NSString stringWithFormat:#"http://tinyurl.com/api-create.php? url=%#", shtUrl];
there is a space after the 'api-create.php?'. This will result in a space in the formated string you are creating and will probably result in URLWithString: being unable to parse the url and returning nil.
Remove the extra space (assuming that it is really there and not just a cut-n-paste error) and see if that fixes the problem.
It's also possible that the shtUrl that you are building a tinyurl for contains special characters that would need to be urlencoded (i.e. percent escaped.) Try adding this:
NSString * encodedShtUrl = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL,
(CFStringRef)shtUrl,
NULL,
(CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ",
kCFStringEncodingUTF8 );
to encode the shtUrl, then use the encodedShtUrl when creating tiny:
NSString * tiny = [NSString stringWithFormat:#"http://tinyurl.com/api-create.php? url=%#", encodedShtUrl];
See http://simonwoodside.com/weblog/2009/4/22/how_to_really_url_encode/ for more about the escaping.
I'm trying to send the contents of UITextView or UITextField as parameters to a php file
NSString *urlstr = [[NSString alloc] initWithFormat:#"http://server.com/file.php?name=%#&tags=%#&entry=%#",nameField.text, tagsField.text, dreamEntry.text];
When i log urlstr, the url format is ok just as long as the UITextView or UITextField don't contain spaces. How would i go about converting the spaces to %20 ?
edit
here is the code at present, which not only crashes but isn't encoding the url properly.
name=John Doe&tags=recurring nightmare&entry=Testing testing testing
is converted to
name=John -1844684964oe&tags=recurringightmare&entry=Testing 4.214929e-307sting -1.992836e+00sting
- (IBAction)sendButtonPressed:(id)sender
{
NSString *urlString = [[NSString alloc] initWithFormat:#"http://server.com/file.php?name=%#&tags=%#&entry=%#", nameField.text, tagsField.text, dreamEntry.text];
NSString *encodedString = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [[NSURL alloc] initWithString:encodedString];
NSLog(encodedString);
NSLog(urlString);
[urlString release];
[url release];
[encodedString release];
}
Actually, all of the previous answers contain at least some inaccuracies, which for many common values of user provided text in the TextFields would not correctly communicate with the server
stringByAddingPercentEscapesUsingEncoding: percent escapes all characters which are not valid URL characters. This method should applied once to the entire URL.
A previous answer claims that stringByAddingPercentEscapesUsingEncoding: works like the URL building classes in many scripting languages, where you should not apply it to the entire URL string, but it doesn't. Anyone can easily verify this by checking its output for unescaped &s and ?s. So it is fine to apply to the entire string, but it is not enough to apply to your 'dynamic' url content.
The previous answer is right in that you have to do some more work to the names and values that go into your CGI query string. Since CGI is specified by RFC3875, this is often referred to as RFC3875 percent escaping. It makes sure that your names and values don't contain characters that are valid URL characters but which are significant in other parts of the URL (;, ?, :, #, &, =, $, +, {, }, <, >, and ,)
However, it is very important to also finish by doing plain URL percent escapes on the full string to make sure that all characters in the string are valid URL characters. While you don't in your example, in general there could be characters in a 'static' part of the string which are not valid URL characters, so you do need to escape those as well.
Unfortunately, NSString doesn't give us the power to escape the RFC3875 significant characters so we have to dip down into CFString to do so. Obviously using CFString is a pain so I generally add a Category onto NSString like so:
#interface NSString (RFC3875)
- (NSString *)stringByAddingRFC3875PercentEscapesUsingEncoding:(NSStringEncoding)encoding;
#end
#implementation NSString (RFC3875)
- (NSString *)stringByAddingRFC3875PercentEscapesUsingEncoding:(NSStringEncoding)encoding {
CFStringEncoding cfEncoding = CFStringConvertNSStringEncodingToEncoding(encoding);
NSString *rfcEscaped = (NSString *)CFURLCreateStringByAddingPercentEscapes(
NULL,
(CFStringRef)self,
NULL,
(CFStringRef)#";/?:#&=$+{}<>,",
cfEncoding);
return [rfcEscaped autorelease];
}
#end
With this Category in place, the original problem could be correctly solved with the following:
NSString *urlEscapedBase = [#"http://server.com/file.php" stringByAddingPercentEscapesUsingEncoding:
NSUTF8StringEncoding];
NSString *rfcEscapedName = [nameField.text stringByAddingRFC3875PercentEscapesUsingEncoding:
NSUTF8StringEncoding];
NSString *rfcEscapedTags = [tagsField.text stringByAddingRFC3875PercentEscapesUsingEncoding:
NSUTF8StringEncoding];
NSString *rfcEscapedEntry = [dreamEntry.text stringByAddingRFC3875PercentEscapesUsingEncoding:
NSUTF8StringEncoding];
NSString *urlStr = [NSString stringWithFormat:#"%#?name=%#&tags=%#&entry=%#",
urlEscapedBase,
rfcEscapedName,
rfcEscapedTags,
rfcEscapedEntry];
NSURL *url = [NSURL URLWithString:urlStr];
This is a little variable heavy just be more clear. Also note that the variable list provided to stringWithFormat: should not be nil terminated. The format string describes the precise number of variables that should follow it. Also, technically the strings for query string names (name, tags, entry,..) should be run through stringByAddingPercentEscapesUsingEncoding: as a matter of course but in this small example we can easily see that they contain no invalid URL characters.
To see why the previous solutions are incorrect, imagine that the user input text in dreamEntry.text contains an &, which is not unlikely. With the previous solutions, all text following that character would be lost by the time the server got that text, since the unescaped ampersand would be interpreted by the server as ending the value portion of that query string pair.
You're not supposed to URL-escape the entire string, you're supposed to URL-escape the dynamic components. Try
NSString *urlStr = [NSString stringWithFormat:#"http://server.com/file.php?name=%#&tags=%#&entry=%#",
[nameField.text stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[tagsField.text stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[dreamEntry.text stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
nil];
NSURL *url = [NSURL URLWithString:urlStr];
The second issue with your code (and undoubtedly the reason for the odd printing) is you're passing the string directly to NSLog, so it's being treated as a format string. You need to use
NSLog(#"%#", encodedString);
instead. That will make it print as expected.
Edit: A third issue with your code is you're mixing autoreleased and owned objects, then releasing them all at the end. Go look at the 3 objects you create, and which you subsequently release later. One of them shouldn't be released later because it was produced by a method that did not start with the words alloc, copy, or new. Identifying the object in question is an exercise left to the reader.
You can take your URL and use:
NSString *urlStr = [[NSString alloc] initWithFormat:#"http://server.com/file.php?name=%#&tags=%#&entry=%#",nameField.text, tagsField.text, dreamEntry.text];
NSString *encStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];