Loading a web page in iphone and check history - iphone

Question

Pseudo code
pageUrl = "http://www.google.com"
if(pageUrl == never Downloaded)
Download pageUrl
else
{
Display Saved Version
Mean while download pageUrl
When done display new version
}
How can I do something like this in objective C for a UIWebview?
Also what's the best way to save web pages for this scenario? PList, SQLite?

Answer 1

Plist is the best way to solve your problem.
iPhone/Objective-c can access very quickly to plist file as compare to SQLite Database.
Let me give you some sample code.
See - edit After some time.
Edit :
Steps for Creating project & connecting web-view
Create New Project -> View Based Application.
Give name "yourProjName" ( up to you what you give )
Open "yourProjNameViewController.xib"
Drag & drop UIWebView
Open "yourProjNameViewController.h" File
Place a variable IBOutlet UIWebView *wView;
Connect in interface builder
Steps for adding Property list file to your project
Expand Resources Group under your project tree
Right click on "Resources" -> Add -> New File
Select Template Category - osx -> Resource
Select Property List file
Give file name "LoadedURL.plist"
Change Root type to Array
Save "LoadedURL.plist" file
Now place following code to "yourProjNameViewController.m" file.
#import "yourProjNameViewController.h"
#define documentsDirectory_Statement NSString *documentsDirectory; \
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); \
documentsDirectory = [paths objectAtIndex:0];
#implementation WebViewLoadViewController
- (void)viewDidLoad {
[super viewDidLoad];
// your url to load
NSString *strToLoad=#"http://www.mail.yahoo.com";
// file management code
// copy file to documents directory
documentsDirectory_Statement;
NSFileManager *fm=[NSFileManager defaultManager];
if(![fm fileExistsAtPath:[documentsDirectory stringByAppendingPathComponent:#"LoadedURL.plist"]]){
[fm copyItemAtPath:[[NSBundle mainBundle] pathForResource:#"LoadedURL" ofType:#"plist"]
toPath:[documentsDirectory stringByAppendingPathComponent:#"LoadedURL.plist"]
error:nil];
}
// array from doc-dir file
NSMutableArray *ar=[NSMutableArray arrayWithContentsOfFile:[documentsDirectory stringByAppendingPathComponent:#"LoadedURL.plist"]];
// check weather file has url data or not.
BOOL fileLocallyAvailable=NO;
NSString *strLocalFileName=nil;
NSUInteger indexOfObject=0;
if([ar count]>0){
for (NSDictionary *d in ar) {
if([[d valueForKey:#"URL"] isEqualToString:strToLoad]){
fileLocallyAvailable=YES;
strLocalFileName=[d valueForKey:#"FileName"];
break;
}
indexOfObject++;
}
}
if(fileLocallyAvailable){
NSDictionary *d=[ar objectAtIndex:indexOfObject];
strLocalFileName=[d valueForKey:#"FileName"];
} else {
NSMutableDictionary *d=[NSMutableDictionary dictionary];
[d setValue:strToLoad forKey:#"URL"];
NSString *str=[[NSString alloc] initWithContentsOfURL:[NSURL URLWithString:strToLoad]];
[str writeToFile:[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%02i.htm",[ar count]]]
atomically:YES
encoding:NSUTF8StringEncoding error:nil];
strLocalFileName=[NSString stringWithFormat:#"%02i.htm",[ar count]];
[d setValue:[NSString stringWithFormat:#"%02i.htm",[ar count]] forKey:#"FileName"];
[ar addObject:d];
[ar writeToFile:[documentsDirectory stringByAppendingPathComponent:#"LoadedURL.plist"]
atomically:YES];
}
NSURL *u=[[NSURL alloc] initFileURLWithPath:[documentsDirectory stringByAppendingPathComponent:strLocalFileName]];
NSURLRequest *re=[NSURLRequest requestWithURL:u];
[wView loadRequest:re];
[u release];
}
`