I am trying to figure out the best approach for queries on a plist. Thus, attempting at making an sql equivalent to "SELECT * FROM sometable WHERE somecol = someval AND someothercol = someotherval AND ".... so on and soforth ... using a plist as the sql table equivalent. Coming from Ruby and mysql, this just seems like a lot of code for one simply query. The results come back as expected (at least at first run they did, I have not tested this rigorously) with no errors.
So here is the question: Is there some simple method hiding in the docs somewhere that would make this less clunky?
and if not what is a better approach?
EPFramework.m
// LOAD PLIST AND FILTER MULTIPLE TIMES
-(NSMutableArray *)loadPlistAndFilterMultipleTimes:(NSString *)plist ArrayOfKeys:(NSArray *)arrayOfKeys ArrayOfKeyValues:(NSArray *)arrayOfKeyValues
{
// set the array counts
int arrayOfKeysCount = [arrayOfKeys count];
int arrayOfKeyValuesCount = [arrayOfKeyValues count];
// initialize the array to return
NSMutableArray *arrayFilteredResults = [[[NSMutableArray alloc] init] retain];
// qualify the search
if(arrayOfKeysCount == arrayOfKeyValuesCount && arrayOfKeysCount > 0 && arrayOfKeyValuesCount > 0)
{
// get the plist
NSString *fullFileName = [NSString stringWithFormat:#"%#.plist", plist];
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:fullFileName];
// put the plist records into an array
NSArray *arrayOfDictionaryItemsInPlist = [[NSMutableArray alloc] initWithContentsOfFile:path];
// load our dynamic array for mutability throughout the loops
NSMutableArray *arrayFiltered = [[[NSMutableArray alloc] initWithArray:arrayOfDictionaryItemsInPlist] retain];
// build an array of the final results to return
for(int i=0; i < arrayOfKeysCount; i ++)
{
// initialize this loops search criteria
NSString *key = [arrayOfKeys objectAtIndex:i];
id value = [arrayOfKeyValues objectAtIndex:i];
// set the filter
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K == %#", key, value];
// filter the result
arrayFilteredResults = [[[NSArray alloc] initWithArray:[arrayFiltered filteredArrayUsingPredicate:predicate]] retain];
}
} else {
NSLog(#"arrOfKeys count does not match arrayOfKeyValues count"); // the search did not qualify
}
// return the results
return arrayFilteredResults;
// release the allocated memory
[arrayFilteredResults release];
}
IndexController.m
NSArray *arrayOfKeys = [NSArray arrayWithObjects:
[NSString stringWithString:#"recordset"],
[NSString stringWithString:#"ep_object_attribute_id"],
nil];
NSArray *arrayOfKeyValues = [NSArray arrayWithObjects:
[NSString stringWithString:#"1778587279"],
[NSNumber numberWithInt:133],
nil];
NSMutableArray *arrayOfResult = [epFrameWork loadPlistAndFilterMultipleTimes:#"FormEntries" ArrayOfKeys:arrayOfKeys ArrayOfKeyValues:arrayOfKeyValues];
NSLog(#"arrayOfResult: %#", arrayOfResult);
Here's the link for fmdb. Should be quick to pick it up, be faster and you get a real database instead of simulating one with plists :)
https://github.com/ccgus/fmdb
Hope that helps
Related
I found a workaround myself, but still trying to understand the problem.
I created a Autocomplete text field with the use of uitableview which is hidden until textfield is edited. The UI part works fine. It's the searching for the results part that's the problem. I declared a local NSMutableDictionary to store my results because I wanted the results to be sorted by the key's values.
if I call keysSortedByValueUsingSelector on the dictionary directly, it crashes. However if I get the keys by [dict allKeys] first, then call sortedArrayUsingSelector, it works fine:
// This commented out line will crash
// NSArray *sortedKeysArray = [dict keysSortedByValueUsingSelector:#selector(compare:)];
// The next two lines runs fine.
NSArray *keyArray = [dict allKeys];
NSArray *sortedKeysArray = [keyArray sortedArrayUsingSelector:#selector(compare:)];
Here is the complete source code for the search method:
- (void)searchAutocompleteEntriesWithSubstring:(NSString *)substring
{
// Put anything that starts with this substring into the autocompleteUrls array
// The items in this array is what will show up in the table view
[autocomplete_symbol_array removeAllObjects];
rRSIAppDelegate *appDelegate = (rRSIAppDelegate *)([[UIApplication sharedApplication] delegate]);
NSString *input_str = [substring uppercaseString];
NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
int i = 0;
for(SymbolInfo *symbol_info in appDelegate.m_symbol_info_array)
{
i++;
NSString *info_str = [[[symbol_info.m_symbol uppercaseString] stringByAppendingString:#"|"] stringByAppendingString:[symbol_info.m_company_name uppercaseString]];
NSUInteger pos = [info_str rangeOfString:input_str].location;
if (pos != NSNotFound)
{
int tmp = pos * 10000 + i;
NSNumber *map_key = [[NSNumber alloc] initWithInt:tmp];
[dict setObject:symbol_info forKey:map_key];
}
}
// This commented out line will crash
// NSArray *sortedKeysArray = [dict keysSortedByValueUsingSelector:#selector(compare:)];
// The next two lines runs fine.
NSArray *keyArray = [dict allKeys];
NSArray *sortedKeysArray = [keyArray sortedArrayUsingSelector:#selector(compare:)];
for (NSNumber *key in sortedKeysArray)
{
SymbolInfo *symbol_info = [dict objectForKey:key];
[autocomplete_symbol_array addObject:symbol_info];
}
// NSLog(#"everything added: %d", [autocomplete_symbol_array count]);
[autocompleteTableView reloadData];
}
The NSMutableDictionary's method is:
- (void)setObject:(id)anObject forKey:(id < NSCopying >)aKey;
This means that the key should implement the NSCopying protocol.
So I have the kind of classic situation where I want to group my tableView by Month/Year. I have a member of my conference object called beginDateSearchString that I use to put different conference into buckets; my problem is in the next part where I try and fail to use a NSSortDescriptor to sort each bucket by beginDate (which is a date).
I am getting an error related to unsorted not being able to receive sort descriptor type selectors.
Here is the disgusting code:
- (NSArray *)arrayOfDateSortedEvents {
NSMutableArray *sortedArray = [[NSMutableArray alloc] init];
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
//place into buckets
for (WSConference *conference in self.arrayOfEvents) {
if (![dictionary objectForKey:[conference beginDateSearchString]]) {
NSMutableArray *array = [[NSMutableArray alloc] initWithObjects:conference,nil];
[dictionary setObject:array forKey:[conference beginDateSearchString]];
}
else {
[[dictionary objectForKey:[conference beginDateSearchString]] addObject:conference];
}
}
//sort each bucket by descriptor beginDate
NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:#"beginDate" ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:descriptor];
for (NSMutableArray *unsorted in dictionary) {
[unsorted sortUsingDescriptors:sortDescriptors];
}
// now, unkey and add dictionary in order
while ([dictionary count] > 0) {
NSString *lowest = nil;
for (NSMutableArray *array in dictionary) {
if (!lowest)
lowest = [[dictionary allKeysForObject:array] objectAtIndex:0];
else {
if ([(WSConference *)[array objectAtIndex:0] beginDate] < [[dictionary objectForKey:lowest] beginDate])
lowest = [[dictionary allKeysForObject:array] objectAtIndex:0];
}
}
[sortedArray addObject:[dictionary objectForKey:lowest]];
[dictionary removeObjectForKey:lowest];
}
return sortedArray;
}
You want to probably filter the array in addition to sorting. See NSPredicate and the NSArray method -filteredArrayUsingPredicate: Then create an eventsByDateArray of the eventArrays created by the filter. Then in your table view delegate for creating the cells, if everything is ordered properly, the first section would represent the date of the events in the eventArray that is the first object of the eventsByDateArray and the table rows would consist of the events in the eventArray. And so on for each date.
Added
Your fast enumeration is incorrect. You enumerate through the keys of the dictionary. So in your code unsorted equals each of the keys as it enumerates. This is a GREAT lesson to everyone. It does not matter how you 'type' a variable. When Objective-C compiles it turns them all into id. So NSMutableArray *unsorted is not an NSMutableArray unless it is assigned to an NSMutableArray. If you assign unsorted to an NSString it will be an NSString. The fast enumerator for a dictionary works using the keys. So, in this case, unsorted becomes an NSString.
Instead of:
for (NSMutableArray *unsorted in dictionary) {
[unsorted sortUsingDescriptors:sortDescriptors];
}
you should have this:
for (id key in dictionary) {
NSMutableArray *unsorted = [dictionary objectForKey:key];
[unsorted sortUsingDescriptors:sortDescriptors];
}
I am trying to use plist files to save a list of items from a text
file from a web site. When I first create the plist file and add
items to that, there is no problem. But when I try to remove an item
from plist, it is not removing the index, it only overwrites the
content of this index with NULL. And I tried an other way; I tried to
create a new array without the item I want to remove, and overwrite
plist file with the content of this new array. In this way, the item
I wanted to remove is removed, but surprisingly the first item gets
NULL! A more surprising situation is, I also write it to a new plist
file with same technique, and it is perferct! This is a very
primitive code, unfortunately it didn't worked for me. I searched
plenty of tutorials, but I couldn't overcome. How can I write the
content of a string array to a plist file without extra null objects
and without loosing datas?
========================================================================
I composed a sample code below :
- (IBAction)logFromPlist{
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
NSLog(#"LOG:");
NSLog(#"arrplist count : %d", [arr count]);
for(int a=0; a<[arr count]; a++){
NSLog(#"*** %#", [arr objectAtIndex:a]);
}
}
- (IBAction)logFromPlist2{
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"]];
NSLog(#"LOG:");
NSLog(#"arrplist count : %d", [arr count]);
for(int a=0; a<[arr count]; a++){
NSLog(#"*** %#", [arr objectAtIndex:a]);
}
}
- (IBAction)addValue{
NSString *deger = [field5 text]; //New value text field in IB
NSMutableArray *arr = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
if(arr == NULL){
arr = [[NSMutableArray alloc] init];
}
[arr addObject:deger];
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] atomically:NO];
}
- (IBAction)removeFromPlist{
NSMutableArray *arr2 = [[NSMutableArray alloc] initWithContentsOfFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"]];
if(arr2 != NULL){
NSMutableArray *arr = [[NSMutableArray alloc] init];
NSString *key = [field8 text];
for(int i = 0; i < [arr2 count]; i++){
NSString *cntStr = [[NSNumber numberWithInt:i] stringValue];
if(![cntStr isEqualToString:key]){
NSString *tempDeger = [arr2 objectAtIndex:i];
if(tempDeger != NULL){
[arr addObject:tempDeger];
}else{
NSLog(#"it is NULL");
}
}
}
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager removeItemAtPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] error:nil]; //I tried this line by removing next line
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] atomically:NO]; //It is writing the array to plist but first item is always null
[arr writeToFile:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"] atomically:NO]; //same technique but everything is ok in this plist
[fileManager copyItemAtPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data3.plist"] toPath:[NSHomeDirectory() stringByAppendingPathComponent:#"Documents/data2.plist"] error:nil]; // trying to copy correct plist file (data3.plist) to original plist file (plist2), but it does not fix the problem.
}
}
Project file : http://www.ozgunbursalioglu.com/files/plistWork.zip
At least your copyItemAtPath: will always fail since it won't overwrite files (data2.plist already exists).
Try to write your file by setting the automatically to YES
[arr writeToFile:PATH atomically:YES];
And also try to check the BOOL value returned to see if your oerration done successfully
I have and array of many strings.
I wan't to sort them into a dictionary, so all strings starting the same letter go into one array and then the array becomes the value for a key; the key would be the letter with which all the words in it's value's array begin.
Example
Key = "A" >> Value = "array = apple, animal, alphabet, abc ..."
Key = "B" >> Value = "array = bat, ball, banana ..."
How can I do that?
Thanks a lot in advance!
NSArray *list = [NSArray arrayWithObjects:#"apple, animal, bat, ball", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in list) {
NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
NSMutableArray *letterList = [dict objectForKey:firstLetter];
if (!letterList) {
letterList = [NSMutableArray array];
[dict setObject:letterList forKey:firstLetter];
}
[letterList addObject:word];
}
NSLog(#"%#", dict);
You can achieve what you want through the following steps:
Create an empty but mutable dictionary.
Get the first character.
If a key for that character does not exist, create it.
Add the word to the value of the key (should be an NSMutableArray).
Repeat step #2 for all keys.
Here is the Objective-C code for these steps. Note that I am assuming that you want the keys to be case insensitive.
// create our dummy dataset
NSArray * wordArray = [NSArray arrayWithObjects:#"Apple",
#"Pickle", #"Monkey", #"Taco",
#"arsenal", #"punch", #"twitch",
#"mushy", nil];
// setup a dictionary
NSMutableDictionary * wordDictionary = [[NSMutableDictionary alloc] init];
for (NSString * word in wordArray) {
// remove uppercaseString if you wish to keys case sensitive.
NSString * letter = [[word substringWithRange:NSMakeRange(0, 1)] uppercaseString];
NSMutableArray * array = [wordDictionary objectForKey:letter];
if (!array) {
// the key doesn't exist, so we will create it.
[wordDictionary setObject:(array = [NSMutableArray array]) forKey:letter];
}
[array addObject:word];
}
NSLog(#"Word dictionary: %#", wordDictionary);
Take a look at this topic, they solves almost the same problem as you — filtering NSArray into a new NSArray in objective-c Let me know if it does not help so I will write for you one more code sample.
Use this to sort the contents of array in alphabetical order, further you design to the requirement
[keywordListArr sortUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
I just wrote this sample. It looks simple and does what you need.
NSArray *names = [NSArray arrayWithObjects:#"Anna", #"Antony", #"Jack", #"John", #"Nikita", #"Mark", #"Matthew", nil];
NSString *alphabet = #"ABCDEFGHIJKLMNOPQRSTUWXYZ";
NSMutableDictionary *sortedNames = [NSMutableDictionary dictionary];
for(int characterIndex = 0; characterIndex < 25; characterIndex++) {
NSString *alphabetCharacter = [alphabet substringWithRange:NSMakeRange(characterIndex, 1)];
NSArray *filteredNames = [names filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"SELF BEGINSWITH[C] %#", alphabetCharacter]];
[sortedNames setObject:filteredNames forKey:alphabetCharacter];
}
//Just for testing purposes let's take a look into our sorted data
for(NSString *key in sortedNames) {
for(NSString *value in [sortedNames valueForKey:key]) {
NSLog(#"%#:%#", key, value);
}
}
Just a conceptual description first:
I am reading input from a text file (a list of words) and putting these words into an NSArray using componentsSeparatedByString method. This works.
But I wanted to select the words randomly and then delete them from the array so as to ensure a different word each time. Of course, you cannot change the NSArray contents. So...
I copied the contents of the NSArray into an NSMutableArray and use IT for the selection source. This also works - 269 objects in each array.
To return a word from the NSMutableArray I use the following code:
note- the arrays are declared globally
as
arrMutTextWords = [[NSMutableArray alloc] init]; //stack for words
arrTextWords = [[NSArray alloc] init]; //permanent store for words
-(NSString*) getaTextWord
{
// if the mutable text word array is empty refill
if ([arrMutTextWords count] == 0){
for (int i = 0 ; i < [arrTextWords count]; i++)
[arrMutTextWords addObject:[arrTextWords objectAtIndex:i]];
}
int i = random() % [arrMutTextWords count];
NSString* ptrWord = [arrMutTextWords objectAtIndex:i];
[arrMutTextWords removeObjectAtIndex:i];
return ptrWord;
}
The program crashes during a call to the method above - here is the calling code:
arrTmp is declared globally arrTmp = [[NSArray alloc] init]; //tmp store for words
for (int i = 0 ; i < 4; i++) {
tmpWord = [self getaTextWord];
[arrTmp addObject:tmpWord];
[arrTmp addObject:tmpWord];
}
I'm thinking that somehow deleting strings from arrMutTextWords is invalidating the NSArray - but I can't think how this would occur.
One possible source for problems is your fetching AND removing the NSString object from your list. Removing it releases that NSString instance therefore devalidating your reference.
To be shure to retain a reference you should use this code sequence instead:
NSString * ptrWord = [[[arrMutTextWords objectAtIndex:i] retain] autorelease];
[arrMutTextWords removeObjectAtIndex:i];
return ptrWord;
By the way: You should use
NSMutableArray *mutableArray = [NSMutableArray arrayWithArray: array];
instead of copying all values by hand. While i do not know the implementation of NSMutableArray, i know from times long ago (NeXTstep), that there are several possible optimizations that may speed up basic NSArray operations.
And finally copying this way is much more concise.
Just ran this through XCode and got random words returned, however I skipped the whole for loop and used addObjectsFromArrayfrom NSMutableArray.
NSArray *randomArray = [[NSArray alloc] initWithObjects:#"Paul", #"George", #"John", nil];
NSMutableArray *muteArray = [[NSMutableArray alloc] init];
[muteArray addObjectsFromArray:randomArray];
int i = random() % [muteArray count];
NSString* ptrWord = [muteArray objectAtIndex:i];
[muteArray removeObjectAtIndex:i];
NSLog(#"ptrWord %#", ptrWord); //gave me a different name each time I ran the function.
Hope this clears some things up.