I have to reload the mainviewcontroller webview second time and reload the webview.
APPDELGATE:
- (void) webViewDidFinishLoad:(UIWebView*) theWebView
{
// only valid if FooBar.plist specifies a protocol to handle
if (self.invokeString)
{
// this is passed before the deviceready event is fired, so you can access it in js when you receive deviceready
NSString* jsString = [NSString stringWithFormat:#"var invokeString = \"%#\";", self.invokeString];
[theWebView stringByEvaluatingJavaScriptFromString:jsString];
}else {
if([loginComplete isEqualToString:#"1"] ){
NSString *page = #"intro.html";
NSString* jsString = [NSString stringWithFormat:#"loadParams('%#','%#','%#');", at,userfbid,page];
[theWebView stringByEvaluatingJavaScriptFromString:jsString];
}
else {
NSString *page = #"friends.html";
NSString* jsString = [NSString stringWithFormat:#"loadParams('%#','%#','%#');", at,userfbid,page];
[theWebView stringByEvaluatingJavaScriptFromString:jsString];
}
// Black base color for background matches the native apps
theWebView.backgroundColor = [UIColor grayColor];
return [self.viewController webViewDidFinishLoad:theWebView];
}
-(void)insert{
self.viewcontroller.webview.delegate=self;
}
Webdelegate is not firing in insert.
Thanks
Try this:
return [self webViewDidFinishLoad:theWebView];
instead of:
return [self.viewController webViewDidFinishLoad:theWebView];
Because your AppDelegate is the delegate for webView's webViewDidFinishLoaded, not webView itself.
Related
I want to use UIPageViewController to implement the ebook reader.
The demo I am sing is AePubReader.
How to use UIPsgeViewController to implement real page turn effect.
How to add set page index while turn pages....
Here next page and previous page Methods:
- (void) gotoNextPage {
if(!paginating){
if(currentPageInSpineIndex+1<pagesInCurrentSpineCount){
[self gotoPageInCurrentSpine:++currentPageInSpineIndex];
} else {
[self gotoNextSpine];
}
}
}
- (void) gotoPrevPage {
if (!paginating) {
if(currentPageInSpineIndex-1>=0){
[self gotoPageInCurrentSpine:--currentPageInSpineIndex];
} else {
if(currentSpineIndex!=0){
int targetPage = [[loadedEpub.spineArray objectAtIndex:(currentSpineIndex-1)] pageCount];
[self loadSpine:--currentSpineIndex atPageIndex:targetPage-1];
}
}
}
}
Thanks....
You can find number of pages in a spine only after rendering the html to webview .I did as follows
- (void) setPagination:(UIWebView *) webView
{
NSString *varMySheet = #"var mySheet = document.styleSheets[0];";
NSString *addCSSRule = #"function addCSSRule(selector, newRule) {"
"ruleIndex = mySheet.cssRules.length;"
"mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);" // For Firefox, Chrome, etc.
"}";
NSString *insertRule1 = [NSString stringWithFormat:#"addCSSRule('html', 'height: %fpx; -webkit-column-gap: 0px; -webkit-column-width: %fpx;')", webView.frame.size.height, webView.frame.size.width];
NSString *insertRule2 = [NSString stringWithFormat:#"addCSSRule('p', 'text-align: justify;')"];
//NSString *setTextSizeRule = [NSString stringWithFormat:#"addCSSRule('body', '-webkit-text-size-adjust: %d%%;')", currentTextSize];
[webView stringByEvaluatingJavaScriptFromString:varMySheet];
[webView stringByEvaluatingJavaScriptFromString:addCSSRule];
[webView stringByEvaluatingJavaScriptFromString:insertRule1];
[webView stringByEvaluatingJavaScriptFromString:insertRule2];
CGSize contentSize = CGSizeMake([[webView stringByEvaluatingJavaScriptFromString:#"document.body.scrollWidth;"] floatValue],
[[webView stringByEvaluatingJavaScriptFromString:#"document.body.scrollHeight;"] floatValue]);
self.pageVO.chapterVO.pageCountInChapter = contentSize.width/webView.frame.size.width;
// NSLog(#"content width : %f ,frame width : %f ,my page count : %f",contentSize.width,webView.frame.size.width,contentSize.width/webView.frame.size.width);
CGPoint point = CGPointMake(0, 0);
if([self checkIsPageIndexOutOfRange])
{
//after decreasing font size page will be left blank
[self.pageVO setIndexOfPage:self.pageVO.chapterVO.pageCountInChapter-1];
[_myDelegate myWebViewOnPageOutOfRange];
}
else
{
if([self.pageVO getIndexOfPage] ==PAGE_INDEX_GREATER_THAN_PAGE_COUNT)
{
//load last page of chapter
[self.pageVO setIndexOfPage:self.pageVO.chapterVO.pageCountInChapter-1];
}
if([self.pageVO getIndexOfPage] !=GET_PAGE_INDEX_USING_WORD_ID)
{
point = CGPointMake([self.pageVO getIndexOfPage]*webView.frame.size.width, 0);
self.scrollView.contentOffset = point;
}
}
[_myDelegate myWebViewDidLoadFinish];
}
Hello I'm parsing html string into web view and here is how I check for youtube videos and add them to iframe:
- (NSString *)extendYouTubeSupportInHtml:(NSString *)html {
static dispatch_once_t onceToken;
static NSRegularExpression *youtubeEmbedRegex;
dispatch_once(&onceToken, ^{
youtubeEmbedRegex = [[NSRegularExpression alloc] initWithPattern:#"<object.*src.*/v/(.*?)['|\"].*object\\s*>" options:NSRegularExpressionCaseInsensitive error:nil];
});
NSArray *matchs;
if (html != nil) {
matchs = [youtubeEmbedRegex matchesInString:html options:0 range:NSMakeRange(0, html.length)];
}else{
matchs = nil;
}
NSInteger rangeOffset = 0;
for (NSTextCheckingResult *match in matchs) {
NSRange objectRange = NSMakeRange([match rangeAtIndex:0].location + rangeOffset, [match rangeAtIndex:0].length);
NSRange idRange = NSMakeRange([match rangeAtIndex:1].location + rangeOffset, [match rangeAtIndex:1].length);
NSString* youtubrId = [html substringWithRange:idRange];
// Add uniq id to img tag
NSString* iframe = [NSString stringWithFormat:#"<iframe src=\"http://www.youtube.com/embed/%#\" frameborder=\"0\" allowfullscreen></iframe>", youtubrId];
html = [html stringByReplacingCharactersInRange:objectRange withString:iframe];
rangeOffset += iframe.length - objectRange.length;
}
return html;
}
And here is how I'm displaying the web view:
- (id)initWithFrame:(CGRect)frame dict:(NSDictionary *)dict {
self = [super initWithFrame:frame];
if (self) {
self.webView = [[[UIWebView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)] autorelease];
self.webView.backgroundColor = [UIColor clearColor];
self.webView.opaque = NO;
self.webView.delegate = self;
self.webView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
self.webView.scalesPageToFit = NO;
self.webView.allowsInlineMediaPlayback = YES;
self.webView.mediaPlaybackRequiresUserAction = NO;
[self removeBackgroundFromWebView:self.webView];
[self addSubview:self.webView];
self.dictionary = dict;
}
return self;
}
My issue is that when I start playing video - memory usage is going up to 30MB, video starts to stutter, audio/video doesn't match, and when i close it - the memory usage is still the same.
I have a couple of leaks in AudioToolbox, also.
I'm using iOS 6 SDK, and iOS 6.
iOS 6 sdk broke the code - now it's not displaying anything in iOS 5.
This is my way of play a youtube video inside a app.
I am using iFrame to load youtube video inside my app.
follow this steps and you will too.
create a uiwebview and connect it to your .h file. Mine is _webView.
Add this method to your .m file.
-(void)embedYouTube{
NSString *embedHTML = #"<iframe width=\"300\" height=\"250\" src=\"http://www.youtube.com/embed/rOPI5LDo7mg\" frameborder=\"0\" allowfullscreen></iframe>";
NSString *html = [NSString stringWithFormat:embedHTML];
[_webView loadHTMLString:html baseURL:nil];
[self.view addSubview:_webView];
}
I am using the embedded code in youtube video. (I hope you know what it is)
call this method inside your viewdidload
[self embedYouTube];
Run the app and you will see the video in your view. This way is perfectly working for me and i think this will help for your too.
- (IBAction)saveButton:(id)sender
{
NSURL *yourURL = [NSURL URLWithString: webpageURLLabel.text ];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:yourURL];
if ([self checkURL] == YES) {
[webpagePreview loadRequest:request];
webpagePreview.scalesPageToFit = YES;
}
}
- (BOOL)checkURL
{
NSString *arrayOfStrings = [NSArray arrayWithObjects:#"http://", #"https://", nil];
NSString *stringToSearchWithin = webpageURLLabel.text;
BOOL found=NO;
for (NSString *s in arrayOfStrings)
{
if ([stringToSearchWithin rangeOfString:s].location != NSNotFound)
{
found = YES;
break;
} else
{
webpageURLLabel.text = [NSString stringWithFormat:#"http://%#", webpageURLLabel.text];
found = YES;
break;
}
}
return found;
}
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
webpageTitleLabel.text = [webpagePreview stringByEvaluatingJavaScriptFromString:#"document.title"];
}
I debugged it and it looks like it is suppose to load. But for some reason, when you tap the button the first time, nothing happens.
If the user taps the button a second time, it works fine. Any suggestions?
Looks to me like the first time the button is clicked, webpageURLLabel.text may not have a valid URL, and so the request is not valid. Then when [self checkURL] is called, webpageURLLabel.text gets set to a valid URL, and so the next click works.
Maybe you should be calling -checkURL before you create the NSURLRequest?
There are also problems in checkURL. Note that it always returns YES. Inside the for loop is logic that reduces to:
if (some condition) {
found = YES;
break;
} else {
// Fix webpageURLLabel.text
found = YES;
break;
}
However, consider what happens if you have a valid entry that starts with #"https://". The first time through the loop the if condition fails and so #"http://" gets added to the front of the URL and you return. So #"https://valid.com" turns into #"http://https://valid.com". You need to move everything in the else outside the for loop and do it only if found is not true.
So below is my code for my controller, which I have four of one for each tab on the tab bar. I have two issues.
I am getting an array out bounds but I can't chase it down. Am I missing something here?
Second when my app starts up it take 5 - 8 seconds before it loads the first view of the tab bar. Once it loads and I click another tab, the tab doesn't turn blue and the app sits there for 3 seconds then finally switches. I am a noob and am struggling here. I think this issue might be fixed by fetching the data in another thread or something? I am sure this controller is full of bugs.
import "AllMackTableViewController.h"
import "PostDetailViewController.h"
import "MackdabMobileAppDelegate.h"
import <QuartzCore/QuartzCore.h>
import "Post.h"
define FONT_SIZE 14.0f
define CELL_CONTENT_WIDTH 254.0f
define CELL_CONTENT_MARGIN 5.0f
#implementation AllMackTableViewController
#synthesize jsonArray;
#synthesize localJsonArray;
#synthesize postDetailViewController;
#synthesize allPostsTableView;
#synthesize fetchedResultsController, managedObjectContext;
#synthesize minuteTimer;
#synthesize regionsTimer;
pragma mark
pragma mark View lifecycle
(void)viewDidLoad {
[super viewDidLoad];
self.title = NSLocalizedString(#"Feed", #"You're Matching Posts");
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
target:self
action:#selector(refresh)];
self.navigationItem.rightBarButtonItem = refreshButton;
allPostsTableView.delegate = self;
[refreshButton release];
[self refresh];
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
(void)scrollViewDidScroll:(UIScrollView *) scrollView;
{
CGFloat scrollHeight = scrollView.contentSize.height;
CGPoint p = scrollView.contentOffset;
//NSLog(#"x = %f, y = %f", p.x, p.y);
}
(void)viewWillAppear:(BOOL)animated {
/*
Set up two timers, one that fires every minute, the other every fifteen minutes.
1/ The time displayed for each time zone must be updated every minute on the minute.
2/ Time zone data is cached. Some time zones are based on 15 minute differences from GMT, so update the cache every 15 minutes, on the "quarter".
*/
NSTimer *timer;
NSDate *date = [NSDate date];
/*
Set up a timer to update the table view every minute on the minute so that it shows the current time.
*/
NSDate *oneMinuteFromNow = [date dateByAddingTimeInterval:60];
NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit;
NSDateComponents *timerDateComponents = [calendar components:unitFlags fromDate:oneMinuteFromNow];
// Add 1 second to make sure the minute update has passed when the timer fires.
[timerDateComponents setSecond:1];
NSDate *minuteTimerDate = [calendar dateFromComponents:timerDateComponents];
timer = [[NSTimer alloc] initWithFireDate:minuteTimerDate interval:60 target:self selector:#selector(updateTime:) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
self.minuteTimer = timer;
[timer release];
}
pragma mark
pragma mark Table view data source
(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 1;
}
(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
// return [self.localJsonArray count];
NSLog(#"Setting numberOfRowsInSection to %i",[self.localJsonArray count]);
if ( [jsonArray count] < 9 ) {
return [self.localJsonArray count];
NSLog(#"Setting numberOfRowsInSection to %i inside of non add one.",[self.localJsonArray count]);
} else {
return [self.localJsonArray count] + 1;
}
}
(void)updateTime:(NSTimer *)timer {
/*
To display the current time, redisplay the time labels.
Don't reload the table view's data as this is unnecessarily expensive it recalculates the number of cells and the height of each item to determine the total height of the view etc. The external dimensions of the cells haven't changed, just their contents.
*/
NSArray *visibleCells = self.tableView.visibleCells;
for (PostTableCustomCellController *cell in visibleCells) {
[cell redisplay];
}
[self updateRegions];
}
(NSString *)dateDiff:(NSString *)origDate {
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setFormatterBehavior:NSDateFormatterBehavior10_4];
[df setDateFormat:#"EEE, dd MMM yy HH:mm:ss VVVV"];
NSDate *convertedDate = [df dateFromString:origDate];
[df release];
NSDate *todayDate = [NSDate date];
double ti = [convertedDate timeIntervalSinceDate:todayDate];
ti = ti * 1;
if(ti < 1) {
return #"never";
} else if (ti < 60) {
return #"less than a minute ago";
} else if (ti < 3600) {
int diff = round(ti / 60);
return [NSString stringWithFormat:#"%d minutes ago", diff];
} else if (ti < 86400) {
int diff = round(ti / 60 / 60);
return[NSString stringWithFormat:#"%d hours ago", diff];
} else if (ti < 2629743) {
int diff = round(ti / 60 / 60 / 24);
return[NSString stringWithFormat:#"%d days ago", diff];
} else {
return #"never";
}
}
(void)updateRegions {
/*
The following sets the date for the regions, hence also for the time zone wrappers. This has the sideeffect of "faulting" the time zone wrappers (see TimeZoneWrapper's setDate: method), so can be used to relieve memory pressure.
*/
NSDate *date = [NSDate date];
for (Post *post in localJsonArray) {
post.timeRemaining = [self dateDiff:post.deadline];
}
}
// Customize the appearance of table view cells.
(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UILabel *distance;
UIImage *image = [UIImage imageNamed:#"imageA.png"];
static NSString *CellIdentifier = #"customCell"; // This is identifier given in IB jason set this.
PostTableCustomCellController *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (indexPath.row != [localJsonArray count] ) {
if (cell == nil) {
NSLog(#"Cell created");
NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:#"PostTableCustomCellController" owner:nil options:nil];
for(id currentObject in nibObjects)
{
if([currentObject isKindOfClass:[PostTableCustomCellController class]])
{
cell = (PostTableCustomCellController *)currentObject;
}
}
}
Post *post = [localJsonArray objectAtIndex:indexPath.row];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy"];
//Optionally for time zone converstions
//[formatter setTimeZone:[NSTimeZone timeZoneWithName:#"..."]];
NSString *stringFromDate = [formatter stringFromDate:post.deadline];
cell.authorName.text = post.author;
cell.deadline.text = stringFromDate;
cell.budget.text = post.budget;
cell.description.text = post.description;
[[cell avatar] setImage:[UIImage imageNamed:#"butterfly.jpeg"]];
[stringFromDate release];
NSLog([NSString stringWithFormat:#"%#", post.distance]);
if([#"" isEqualToString: post.distance] || nil == post.distance) {
cell.distance.text = #"1 mi.";
}else{
cell.distance.text = #"25 mi.";
}
Post *myPost = [localJsonArray objectAtIndex:[indexPath row]];
// Might can remove these
UILabel *locationLabel = (UILabel *) [cell distance];
UITextView *postTextView = (UITextView *) [cell description];
//CGSize maximumLabelSize = CGSizeMake(254,88.0f);
NSString *text;
CGSize constraint;
CGSize size;
CGFloat height;
CGFloat realHeight;
CGSize expectedLabelSize;
text = myPost.description;
constraint = CGSizeMake(CELL_CONTENT_WIDTH (CELL_CONTENT_MARGIN * 2), 88.0f);
size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
height = MAX(size.height, 35.0f);
realHeight = height + 36.0f (10);
expectedLabelSize = [text sizeWithFont:[UIFont boldSystemFontOfSize:18.0f] constrainedToSize:CGSizeMake(252.0f, CGFLOAT_MAX) lineBreakMode:UILineBreakModeWordWrap];
CGRect newFrame = postTextView.frame;
newFrame.size.height = expectedLabelSize.height;
newFrame.size.width = 252;
postTextView.frame = newFrame;
[[cell description] sizeToFit];
[[cell viewForBackground] sizeToFit];
[cell setNeedsDisplay];
}// Ok, all done for filling the normal cells, next we probaply reach the +1 index, which doesn’t contain anything yet
if ( [jsonArray count] == 9 ) { // Only call this if the array count is 25
if(indexPath.row == [localJsonArray count] ) { // Here we check if we reached the end of the index, so the +1 row
if (cell == nil) {
cell = [[[PostTableCustomCellController alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
// Reset previous content of the cell, I have these defined in a UITableCell subclass, change them where needed
cell.authorName.text = nil;
cell.deadline.text = nil;
cell.budget.text = nil;
cell.description.text = nil;
// Here we create the ‘Load more’ cell
UILabel *loadMore =[[UILabel alloc]initWithFrame: CGRectMake(20,0,362,100)];
loadMore.textColor = [UIColor blackColor];
loadMore.highlightedTextColor = [UIColor darkGrayColor];
loadMore.backgroundColor = [UIColor clearColor];
loadMore.font=[UIFont fontWithName:#"Verdana" size:20];
loadMore.textAlignment=UITextAlignmentCenter;
loadMore.font=[UIFont boldSystemFontOfSize:20];
loadMore.text=#"Load More..";
[cell addSubview:loadMore];
}
}
return cell;
}
(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
if (indexPath.row != [localJsonArray count] ) {
Post *myPost = [localJsonArray objectAtIndex:[indexPath row]];
NSString *text = myPost.description;
CGSize constraint = CGSizeMake(CELL_CONTENT_WIDTH (CELL_CONTENT_MARGIN * 2), 88.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
CGFloat height = MAX(size.height, 35.0f);
return height + (CELL_CONTENT_MARGIN * 2) + 28.0f;
}else{
return 100.0f;
}
}
(IBAction)nextTwentyFivePlease:(NSString *)thePostID{
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
self.jsonArray = [Post findNextTwentyFiveRemote:thePostID];
if (self.localJsonArray == nil) {
self.localJsonArray = [[NSMutableArray alloc]init]; // init the local array if it’s empty
}
[self.localJsonArray addObjectsFromArray:self.jsonArray];
[self.tableView reloadData];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
(IBAction)refresh {
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
self.jsonArray = [Post findAllRemote];
if (self.localJsonArray == nil) {
self.localJsonArray = [[NSMutableArray alloc]init]; // init the local array if it’s empty
}
[self.localJsonArray addObjectsFromArray:self.jsonArray];
//self.localJsonArray = [Post findAllRemote];
[self.tableView reloadData];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
pragma mark
pragma mark Table view delegate
(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if ( [jsonArray count] == 9 ) { // only check for the load more function if we have 25 results in the dynamic array
if (indexPath.row == [localJsonArray count] ) { // See if we reached the +1 in the results
Post *tempPost = [jsonArray objectAtIndex:indexPath.row];
NSLog('What is at tempPost');
[self nextTwentyFivePlease:tempPost.postID]; // function to load more results
}
} else {
NSInteger row = [indexPath row];
if (self.postDetailViewController == nil) {
PostDetailViewController *aPostDetail = [[PostDetailViewController alloc] initWithNibName:#"PostDetailView" bundle:nil];
self.postDetailViewController = aPostDetail;
postDetailViewController.post = [localJsonArray objectAtIndex:row];
[aPostDetail release];
}
postDetailViewController.title = [NSString stringWithFormat:#"Details"];
MackdabMobileAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
[delegate.allMacksNavController pushViewController:postDetailViewController animated:YES];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
}
pragma mark
pragma mark Timer set accessor methods
(void)setMinuteTimer:(NSTimer *)newTimer {
if (minuteTimer != newTimer) {
[minuteTimer invalidate];
minuteTimer = newTimer;
}
}
(void)setRegionsTimer:(NSTimer *)newTimer {
if (regionsTimer != newTimer) {
[regionsTimer invalidate];
regionsTimer = newTimer;
}
}
pragma mark
pragma mark Memory management
(void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc that aren't in use.
}
(void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
}
(void)dealloc {
[allPostsTableView release];
[postDetailViewController release];
[localJsonArray release]; // may need to remove this
[super dealloc];
}
#end
In your refresh method which is called in viewDidLoad, it appears that it is doing a bunch of network access to download some information. That would explain why it is taking so long to show your initial tab.
You'll want to do that network access in a background thread so that your UI doesn't block. Then once you've gotten the results back you can update your UI from the main thread. Something like:
- (IBAction) refresh {
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[self performSelectorInBackground:#selector(refreshInBackground) withObject:nil];
}
- (void) refreshInBackground {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
self.jsonArray = [Post findAllRemote];
if (self.localJsonArray == nil) {
self.localJsonArray = [[NSMutableArray alloc]init]; // init the local array if it’s empty
}
[self.localJsonArray addObjectsFromArray:self.jsonArray];
[self performSelectorOnMainThread:#selector(refreshComplete) withObject:nil waitUntilDone:NO];
}
- (void) refreshComplete {
[self.tableView reloadData];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
EDIT: As Rob noted in the comment below, you'll want to add some kind of flag (or semaphore) to avoid firing off multiple -refresh calls at the same time. Threading and race conditions are always a tricky bit, but my goal above was just to get you moving in the right direction so that you can use background threads for your network calls.
This problem is probably not specific to MFMailComposeViewController, but that is where I am having the problem...
I am building the NSString
"myEmailString" for the messageBody of
the MFMailComposeViewController and
storing it in an iVar before
displaying the
MFMailComposeViewController as a
modal view controller.
I pass the string into the MFMailComposeViewController, then present it as a modal view controller.
When the modal view controller is dismissed, my iVar becomes invalid,
and the app crashes when I release the emailString iVar in dealloc
Code below, what am I doing wrong?
-(void)buildEmailMessage {
int mySection;
int myRow;
NSString *buildString = [NSString stringWithFormat:#"<b><p>Ten Essentials Check List</b><br />%#</p>", [myList valueForKey:#"listName"]];
for (mySection = 0; mySection < [[fetchedResultsController sections] count]; mySection ++) {
NSString *sectionName = [NSString stringWithFormat:#"<p><b>%# Group</b></p><ul>", [[[fetchedResultsController sections] objectAtIndex:mySection] name]];
buildString = [buildString stringByAppendingString:sectionName];
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:mySection];
for (myRow = 0; myRow < [sectionInfo numberOfObjects]; myRow ++) {
// Get the managedObject
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:myRow inSection:mySection];
NSManagedObject *managedObject = [fetchedResultsController objectAtIndexPath:indexPath];
//Get the related Item object
Item *item = [managedObject valueForKey:#"item"];
NSString *itemName = [NSString stringWithFormat:#"<li>%#</li>", item.itemName];
buildString = [buildString stringByAppendingString:itemName];
}
buildString = [buildString stringByAppendingString:#"</ul>"];
}
myEmailString = [NSString stringWithString:buildString];
NSLog(#"email string = :\n%#", myEmailString);
[self showPicker];
}
#pragma mark -
#pragma mark Send Mail
-(void)showPicker {
// This code can run on devices running iPhone OS 2.0 or later
// The MFMailComposeViewController class is only available in iPhone OS 3.0 or later.
// So, we must verify the existence of the above class and provide a workaround for devices running
// earlier versions of the iPhone OS.
// We display an email composition interface if MFMailComposeViewController exists and the device can send emails.
// We launch the Mail application on the device, otherwise.
NSLog(#"Checking OS for MFMailComposeViewController");
Class mailClass = (NSClassFromString(#"MFMailComposeViewController"));
if (mailClass != nil)
{
// We must always check whether the current device is configured for sending emails
if ([mailClass canSendMail])
{
[self displayComposerSheet];
}
else
{
[self launchMailAppOnDevice];
}
}
else
{
[self launchMailAppOnDevice];
}
}
// Displays an email composition interface inside the application. Populates all the Mail fields.
-(void)displayComposerSheet {
MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
picker.mailComposeDelegate = self;
picker.navigationBar.barStyle = UIBarStyleBlack;
[picker setSubject:#"Here is your gear check list!"];
// Attach an image to the email
NSString *path = [[NSBundle mainBundle] pathForResource:#"Checkmark_icon" ofType:#"png"];
NSData *myData = [NSData dataWithContentsOfFile:path];
[picker addAttachmentData:myData mimeType:#"image/png" fileName:#"Checkmark_icon"];
// Fill out the email body text
//***** NOTE: This is where I pass the value from my iVar *****
// into the MFMailComposeViewController
//
NSString *emailBody = [NSString stringWithString:myEmailString];
[picker setMessageBody:emailBody isHTML:YES];
NSLog (#"DIsplaying Composer Sheet");
[self presentModalViewController:picker animated:YES];
[picker release];
}
// Dismisses the email composition interface when users tap Cancel or Send. Proceeds to update the message field with the result of the operation.
- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error {
//message.hidden = NO;
// Notifies users about errors associated with the interface
switch (result)
{
case MFMailComposeResultCancelled:
NSLog (#"Result: canceled");
break;
case MFMailComposeResultSaved:
NSLog (#"Result: saved");
break;
case MFMailComposeResultSent:
NSLog (#"Result: sent");
break;
case MFMailComposeResultFailed:
NSLog (#"Result: failed");
break;
default:
NSLog (#"Result: not sent");
break;
}
[self dismissModalViewControllerAnimated:YES];
// ***** NOTE: Line below was added to fix the invalid iVar problem *****
myEmailString = #"";
}
#pragma mark -
#pragma mark Workaround
// Launches the Mail application on the device.
-(void)launchMailAppOnDevice {
NSString *recipients = #"mailto:first#example.com?cc=second#example.com,third#example.com&subject=Here is your gear check list!";
NSString *body = myEmailString;
NSString *email = [NSString stringWithFormat:#"%#%#", recipients, body];
email = [email stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:email]];
}
- (void)dealloc {
[managedObjectContext release];
[fetchedResultsController release];
[tableview release];
[myList release];
[myEmailString release];
[super dealloc];
}
how is your ivar declared? is it declared as a property? in any case, it is not automatically retained for you.
Either you need to do
myEmailString = [[NSString stringWithString:buildString] retain];
or
self.myEmailString = [NSString stringWithString:buildString];
if you have myEmailString declared as
#property (nonatomic, retain) NSString *myEmailString
Think about it: if all ivars were automatically retained for you, then how would you have a variable that you didn't want to retain? That's why it doesn't work that way.
when you are creating the myEmail string in buildEmailMessage you are never retaining the string. Thus after leaving the function it is autoreleased. Your retain count then when dealloc is called will be 0, which will cause the crash. If you want to keep the variable you will need to have the line as follows
myEmailString = [[NSString stringWithString:buildString] retain];
then you can call [myEmailString release] safely
stringWithString: creates a new string and autoreleases it before returning it to you. Unless you retain the returned string, you don't need to release it in your dealloc method.
You should be retaining your string before storing it in your iVar:
myEmailString = [[NSString stringWithString:buildString] retain];
It becomes invalid without this due to it being autoreleased later during the execution of your program. This will also ensure it's still allocated when your destructor is called, preventing release crashing.