how to remove object from array at particular index - iphone

I am doing parsing on xml file and fetched data from xml file and store that in array and further to rows of UITableView. I want to remove the extra word at 5th index '\U2019' and want to merge word 'i' and 'm all alone' to one row f UITableView.
"WHERE DOES LOVE LIVE",
"TRANSFORMATION OF THE SELF",
"EMPATHY STRUCTURES",
"MORE QUESTIONS THAN ANSWERS",
I,
"\U2019",
"M ALL ALONE",
"THE WILL TO LIVE",
"THE GUILT OF SELF DENIAL",
HOPELESSNESS,
"SOCIAL WANNABIES",
"THE POWER OF HOPE"
bunch of code:
- (UITableViewCell *)tableView:(UITableView *)tableViewcellForRowAtIndexPath:
(NSIndexPath *)indexPath
{ static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero];
}
if(indexPath.row > 0)
{ cell.textLabel.text = [blogtitle objectAtIndex: indexPath.row];
}}`
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSMutableString *)string
{
NSString *newString = [string stringByTrimmingCharactersInSet:
[NSCharacterSet whitespaceAndNewlineCharacterSet]];
// save the characters for the current item...
if ( [currentElement isEqualToString:#"title"])
{
if ([newString length] > 0)
{
// NSMutableString *base64String = [newString base64EncodedString];
[blogtitle addObject:newString];
}
NSLog(#"blogtiltlearray...%#",blogtitle);
}}`

It's easy to remove an object at a specific index. Try:
[blogtitle removeObjectAtIndex:index];
EDIT: You can call [tableView reloadData]; in order to remove the row, assuming you've already loaded the tableView BEFORE you manipulated the array.
You can merge 2 strings together via:
NSString * mergedString = [NSString stringWithFormat:#"%#%#", string1, string2];
and you can replace one object in an array with another via:
[blogtitle replaceObjectAtIndex:index withObject:mergedString];
Hope that helps!

You can use NSMutable array and the method of it named removeObjectAtIndex:

Related

UITableView not reversing

I'm working on information retrieval where in the latest information in on top of UITableView. The code goes like this.
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
LoanModel* loan = _feed.products[indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" ];
if (cell == nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:#"Cell"];
}
NSString *myString = [NSString stringWithFormat:#"%#",[loan name]];
NSArray *myWords = [myString componentsSeparatedByString:#","];
NSMutableArray *reversed = [NSMutableArray arrayWithCapacity:[myWords count]];
NSEnumerator *enumerator = [myWords reverseObjectEnumerator];
for (id element in enumerator) {
[reversed addObject:element];
}
NSMutableString *reverseString = [reversed componentsJoinedByString:#","];
cell.textLabel.text = reverseString;
return cell;
}
I'm getting the JSON object which contain two fields cid and name respectively. I'm showing only the name is tableview. But I want to show it in reverse i,e last update should show at first. But above code showing the content in reverse. IF "hello" is the content, then it shows "olleh". Please suggest me how to get the UITableView in reverse list. I'm a newbie to iOS.
If you want to have the reversed order of cells / objects they represent, you have to change
LoanModel* loan = _feed.products[indexPath.row];
to
LoanModel* loan = _feed.products[_feed.products.count - 1 - indexPath.row];
assuming that _feed.products is an NSArray.
The array you are using to display the the data in tableView, you'll need to reverse that and then display the data in tableView
NSArray* reversed = [[myArray reverseObjectEnumerator] allObjects];
you can use this to make your array objects order in reverse.
Try This:
NSArray* reversedArray = [[myWords reverseObjectEnumerator] allObjects];

Storing a history list in objective c

I am doing a project to scan qr codes.a.
In this project a history page is present in which i have to show the history of user's scans.
It contains URLs only. So I am planning to show the list of urls he scanned previously in a table view.
How can i save the history list? help, please. can I use NSMutable array or something to save the scanned urls like this[myArray writeToURL:aURL atomically:NO];
yes for this you have to create a internel database using sqlite or coredata wherever user scan the qrcode store into database and wherever user wants to see history then fetch from database and display whatever method you use to dispaly
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingString:#"/"];
NSString *fullPathToFile = [filePath stringByAppendingPathComponent:#"myfile.plist"];
[myArray writeToFile:fullPathToFile atomically:YES];
Yes you can.
Your table view needs to implement a UITableViewDataSource to use the NSMutableArray as the source of your table view: (here using myArray as the array in this sample code)
-(void)saveToHistoryArray:(NSString *)urlAsString {
[myArray addObject:urlAsString];
[self.tableView reloadData];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
/* insert error checking here */
return [myArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = [myArray objectAtIndex:indexPath.row];
return cell;
}

Deleting records in UITableViewController throws error

Problem: When I click the delete button for a given table/section row, i get the following error: "*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (4) must be equal to the number of rows contained in that section before the update (4), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted).'"
From other posts I have read about this symptom, I gather I am suppose to be manually removing an element in my datasource array, but not sure how to access the section's array inside this method:
// COMMIT EDITING STYLE
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"indexPath: %#", indexPath);
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the row from the data source
[tableView beginUpdates];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView endUpdates]; // throws error here
[tableView reloadData];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
I think the complication for this situation arises due to the fact that the plist (FormEntries.plist) I am pulling data from holds user input for all sorts of things all through out my app, thus I am having to call and filter it for every section. This works fine to populate the UITableView and all of it's sections, but because a new filtered array is being created for and inside each section, I'm not sure how to ever access it again in order to remove the element, thus rectifying the above error message. Here is how I am loading the data for each table section:
// CELL FOR ROW AT INDEXPATH
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath (NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
NSNumber *numScreenId = [[arrayOfModulesScreens objectAtIndex: indexPath.section] objectForKey: #"id"];
NSMutableArray *arrayRecords = [epFrameWork selectPlist: #"FormEntries" filterByKey: #"screen_id" keyValue:numScreenId];
NSString *strTitle = [[arrayRecords objectAtIndex: indexPath.row] objectForKey: #"storage_string"];
cell.textLabel.text = strTitle;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
-- Not sure if this will help diagnose things, but here it is none the less ---
// TITLE FOR HEADER IN SECTION
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return [[arrayOfModulesScreens objectAtIndex: section] objectForKey: #"screen_title"];
}
// NUMBER OF SECTIONS IN TABLE VIEW
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [arrayOfModulesScreens count];
}
// NUMBER OF ROWS IN SECTION
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSNumber *numScreenId = [[arrayOfModulesScreens objectAtIndex: section] objectForKey: #"id"];
NSMutableArray *arrayRecords = [epFrameWork selectPlist: #"FormEntries" filterByKey: #"screen_id" keyValue:numScreenId];
int rowCount = [arrayRecords count];
return rowCount;
}
What is the best approach to handle this situation or to resolve the above posted error message?
-- UPDATE --
So here is how I'm trying to identify which plist record to delete, assuming that's what I need to do to resolve the original error:
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
int g = indexPath.row;
int count = -1;
UITableViewCell *tvc = [[UITableViewCell alloc] init];
for(id element in tableView.subviews) {
if([element isKindOfClass:[UITableViewCell class]]) {
count +=1;
NSLog(#"g: %d - count: %d", g , count);
if(count == g) {
tvc = element;
NSLog(#"tvc: %# - UID: %# - g: %d - count: %d", tvc, tvc.detailTextLabel.text, g , count);
}
}
}
My logic here was to set a hidden unique identifier on tvc.detailTextLabel.text in the cellForRowAtIndexPath method, which in turn would let me know which record from the plist to filter and delete by calling [array removeObjectAtIndex:uid] where array is my filtered plist array. Only problem now is that tvc in the NSLog always returns the record at index 0, not the row that holds the delete button I click.
NSLog returns: tvc: < UITableViewCell: 0x713e2c0; frame = (0 30; 320 44); text = 'Church A'; autoresize = W; layer = < CALayer: 0x7113e70 > > - UID: -237206321 - g: 3 - count: 3. So why would tvc return the index 0 when it was index 3 I clicked the delete button?
Is this just becoming a clustered mess or is there a cleaner solution? But ya, still stumped.
This error most definitely relates to your mishandling the data that you are trying to load to your table. I found that the easiest and safest way to handle modifying table content is to do something along those lines, with the necessary adjustments (within tableView:commitEditingStyle:)
//REMOVE A CELL FROM A SECTION
[yourTable beginUpdates];
[yourTable deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationBottom];
[yourTable endUpdates];
[yourTable reloadData];
In addition you need to make sure that your array is properly updated to have the changes reflected in the table.
This is how I was finally able to resolve the issue:
I changed all of this crap:
int g = indexPath.row;
int count = -1;
UITableViewCell *tvc = [[UITableViewCell alloc] init];
for(id element in tableView.subviews) {
if([element isKindOfClass:[UITableViewCell class]]) {
count +=1;
NSLog(#"g: %d - count: %d", g , count);
if(count == g) {
tvc = element;
NSLog(#"tvc: %# - UID: %# - g: %d - count: %d", tvc, tvc.detailTextLabel.text, g , count);
}
}
}
to one simple line:
UITableViewCell *cell = [[self tableView] cellForRowAtIndexPath:indexPath];
This allowed me to identify the cell I was working with. So my final code that worked looks like this:
// COMMIT EDITING STYLE
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
UITableViewCell *cell = [[self tableView] cellForRowAtIndexPath:indexPath];
[epFrameWork deleteRecordFromPlist:#"FormEntries" uid:cell.detailTextLabel.text];
[tableView reloadData];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
-(void) deleteRecordFromPlist:(NSString *)plist uid:(NSString *)uId {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *tmpFileName = [[NSString alloc] initWithFormat:#"%#.plist", plist];
NSString *path = [documentsDirectory stringByAppendingPathComponent:tmpFileName];
NSMutableArray *array = [[NSMutableArray alloc] initWithContentsOfFile:path];
NSDictionary *dict = [[NSDictionary alloc] init];
NSString *tmpUid;
for(int i=0; i < [array count]; i++) {
dict = [array objectAtIndex:i];
tmpUid = [dict valueForKey:#"uid"];
if([tmpUid isEqualToString:uId]) {
[array removeObjectAtIndex:i];
[array writeToFile:path atomically:YES];
}
}
}

Reading plist into TableView

I started this project with a simple plist of a dictionary with two arrays of strings. I now want to add more information and want to use this plist structure:
Root - Dictionary - (2 items)
Standard - Array - (3 items)
Item 0 - Dictionary - (4 items)
Color - String - Red
Rvalue - String - 255
Gvalue - String - 0
Bvalue - String - 0
Sorry about typing in the plist but the site would not let me post an image
I know that the RGB values could be numbers instead of strings but I have a reason for them being strings.
This is the code I used to read the simple plist:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSUInteger section = [indexPath section];
NSUInteger row = [indexPath row];
NSString *key = [keys objectAtIndex:section];
NSArray *colorSection = [colors objectForKey:key];
static NSString *SectionsTableIdentifier = #"SectionsTableIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:SectionsTableIdentifier];
if(cell == nil){
cell=[[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier: SectionsTableIdentifier] autorelease];
}
cell.textLabel.text = [colorSection objectAtIndex:row];
[cell setAccessoryType:UITableViewCellAccessoryDetailDisclosureButton]; //add disclosure button to rows
return cell;
}
My question is what is the specific code to retrieve the contents of the color dictionaries to get the Colors for the cell.textLabel.text and also read the RGB values to add a subtitle. I've been working on this for several days and have read references and lots of examples and unfortunately can't solve the problem. Your assistance will be greatly appreciated.
So providing you have your Standard - Array stored against a Array you've defined in your .h file then something like this would work. In this example the array is stored against self.coloursArray.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *SectionsTableIdentifier = #"SectionsTableIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:SectionsTableIdentifier];
if(cell == nil){
cell=[[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier: SectionsTableIdentifier] autorelease];
}
NSString* ColourString = [[self.coloursArray objectAtIndex:indexPath.row] valueForKey:#"Colour"];
NSString* rValue = [[self.coloursArray objectAtIndex:indexPath.row] valueForKey:#"Rvalue"];
NSString* gValue = [[self.coloursArray objectAtIndex:indexPath.row] valueForKey:#"Gvalue"];
NSString* bValue = [[self.coloursArray objectAtIndex:indexPath.row] valueForKey:#"Bvalue"];
cell.textLabel.text = ColourString;
NSString* subCellString = [NSString stringWithFormat:#"%#:%#:%#", rValue, gValue, bValue];
}
Hopefully that'll give a a hand.
First, do not use -[UITableViewCell initWithFrame:reuseIdentifier:]. It has been deprecated and will give you a warning, plus it will make your subtitle harder to implement. This code is a modified version of yours which loads the information, sets the title to the Color property, and sets the subtitle to a string containing the Rvalue, Gvalue, and Bvalue properties.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSUInteger section = [indexPath section];
NSUInteger row = [indexPath row];
NSString *key = [keys objectAtIndex:section];
NSArray *colorSection = [colors objectForKey:key];
static NSString *SectionsTableIdentifier = #"SectionsTableIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:SectionsTableIdentifier];
if(cell == nil) {
cell=[[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier: SectionsTableIdentifier] autorelease];
}
NSDictionary *color = [colorSection objectAtIndex:row];
cell.textLabel.text = [color objectForKey:#"Color"];
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#, %#, %#",[color objectForKey:#"Rvalue"],[color objectForKey:#"Gvalue"],[color objectForKey:#"Bvalue"]];
[cell setAccessoryType:UITableViewCellAccessoryDetailDisclosureButton]; //add disclosure button to rows
return cell;
}

Split and Swap String in Objective C (iPhone)

Hi I have an array of strings separated with a delimeter ":". I tried separating strings using componentsSeparatedByString method and then save the result into an array and later use that array to produce the desired output, but it didn't worked.
For example
Now my UITableView displays cells as:
Case 1:
How:Many
Too:Many
Apple:Milk
iPhone:Simulator
I want the cells to be displayed on UITableView as:
Case 2:
Many How
Many Too
Milk Apple
Simulator iPhone
This is my cellForRowAtIndexPath method:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
NSString *entry=[entryKeys objectAtIndex:[indexPath section]];
NSArray *entrySection=[entries objectForKey:entry];
cell.textLabel.text=[entrySection objectAtIndex:[indexPath row]]
}
return cell;
}
The output of the above method is case 1 but I want the output to be case 2
entryKeys has keys from A-Z and entry section has values sorted and listed for respective keys i.e. entries starting with A grouped under key A so on...
It may sound silly but I am still learning..please help me
There are numerous ways to do this. Here's one;
// get your raw text in the form of "AAA:BBB"
NSString *rawText = [entrySection objectAtIndex:[indexPath row]];
// split the text by the : to get an array containing { "AAA", "BBB" }
NSArray *splitText = [rawText componentsSeparatedByString:#":"];
// form a new string of the form "BBB AAA" by using the individual entries in the array
NSString *cellText = [NSString stringWithFormat:#"%# %#", [splitText objectAtIndex:1], [splitText objectAtIndex:0]];
Hope that helps.
Wouldn't stringByReplacingOccurrencesOfString:withString: be easier?