I'm trying to get the attributes of a keychain item. This code should look up all the available attributes, then print off their tags and contents.
According to the docs I should be seeing tags like 'cdat', but instead they just look like an index (i.e., the first tag is 0, next is 1). This makes it pretty useless since I can't tell which attribute is the one I'm looking for.
SecItemClass itemClass;
SecKeychainItemCopyAttributesAndData(itemRef, NULL, &itemClass, NULL, NULL, NULL);
SecKeychainRef keychainRef;
SecKeychainItemCopyKeychain(itemRef, &keychainRef);
SecKeychainAttributeInfo *attrInfo;
SecKeychainAttributeInfoForItemID(keychainRef, itemClass, &attrInfo);
SecKeychainAttributeList *attributes;
SecKeychainItemCopyAttributesAndData(itemRef, attrInfo, NULL, &attributes, 0, NULL);
for (int i = 0; i < attributes->count; i ++)
{
SecKeychainAttribute attr = attributes->attr[i];
NSLog(#"%08x %#", attr.tag, [NSData dataWithBytes:attr.data length:attr.length]);
}
SecKeychainFreeAttributeInfo(attrInfo);
SecKeychainItemFreeAttributesAndData(attributes, NULL);
CFRelease(itemRef);
CFRelease(keychainRef);
There are two things you should be doing here. Firstly, you need to handle "generic" itemClasses before the call to SecKeychainAttributeInfoForItemID...
switch (itemClass)
{
case kSecInternetPasswordItemClass:
itemClass = CSSM_DL_DB_RECORD_INTERNET_PASSWORD;
break;
case kSecGenericPasswordItemClass:
itemClass = CSSM_DL_DB_RECORD_GENERIC_PASSWORD;
break;
case kSecAppleSharePasswordItemClass:
itemClass = CSSM_DL_DB_RECORD_APPLESHARE_PASSWORD;
break;
default:
// No action required
}
Second, you need to convert the attr.tag from a FourCharCode to a string, i.e.
NSLog(#"%c%c%c%c %#",
((char *)&attr.tag)[3],
((char *)&attr.tag)[2],
((char *)&attr.tag)[1],
((char *)&attr.tag)[0],
[[[NSString alloc]
initWithData:[NSData dataWithBytes:attr.data length:attr.length]
encoding:NSUTF8StringEncoding]
autorelease]]);
Notice that I've also output the data as a string -- it almost always is UTF8 encoded data.
I think the documentation leads to a bit of confusion.
The numbers I'm seeing appear to be keychain item attribute constants for keys.
However, SecKeychainItemCopyAttributesAndData returns a SecKeychainAttributeList struct, which contains an array of SecKeychainAttributes. From TFD:
tag
A 4-byte attribute tag. See “Keychain Item Attribute Constants” for valid attribute types.
The attribute constants (of the non-"for keys" variety) are the 4-char values I expected to see.
Related
I am using UIManagedDocument with Parent Child context.
In my child context I do the following
Code 1
NSSet *results = [self.event.memberships filteredSetUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
return ([[evaluatedObject deleted] boolValue] == NO);
}]];
Above code returns the expected results (only Not deleted members for the event).
Code 2
But this code does not. It fetches all records.
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"deleted == NO"];
NSSet *results = [self.event.memberships filteredSetUsingPredicate:predicate];
It seems confusing. Both should return same results, but predicateWithBlock returns correct results where as predicateWithFormat returns all records.
What are the pros and cons of using predicateWithBlock instead of predicateWithFormat?
The problem is that you have defined an attribute deleted for your entity. That conflicts with the isDeleted method of NSManagedObject, so you should rename that attribute.
The following "experiment" shows that strange things happen if you call your attribute "deleted" (c is a managed object with a custom deleted attribute):
// Set custom "deleted" property to YES:
c.deleted = #YES;
// Use the property, as your Code 1
NSLog(#"%#", [c deleted]);
// Output: 1
// Use Key-Value Coding, as your Code 2
NSLog(#"%#", [c valueForKey:#"deleted"]);
// Output: 0
// Now really delete the object and try again:
[context deleteObject:c];
NSLog(#"%#", [c valueForKey:#"deleted"]);
// Output: 1
Your "Code 1" refers to the property, therefore it returns the expected result. "Code 2" uses Key-Value Coding, and [c valueForKey:#"deleted"] returns YES if the object
actually has been deleted from the context!
So renaming that attribute should solve your problem. Unfortunately the compiler does not
emit warnings if an attribute name conflicts with a built-in method.
Use the formatting placeholder to replace the bool value:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K == %#",
#"deleted", #(NO)];
Your use of the key path is probably ok, but the right-hand side probably doesn't look like "NO" to the parser.
I have one CoreData record that contains all of the app's settings. When I read that single record (using MagicalRecord), I get an array back. My question is: can I get addressabiltiy to the individual fields in the record without using "[0]" (field index), but rather using [#"shopOpens"]?
I was thinking something like this, but I don't think it's right:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"aMostRecentFlag == 1"]; // find old records
preferenceData = [PreferenceData MR_findAllWithPredicate:predicate inContext:defaultContext]; // source
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *preferencesDict = [[userDefaults dictionaryForKey:#"preferencesDictionary"] mutableCopy]; // target
// start filling the userDefaults from the last Preferences record
/*
Printing description of preferencesDict: {
apptInterval = 15;
colorScheme = Saori;
servicesType = 1;
shopCloses = 2000;
shopOpens = 900;
showServices = 0;
syncToiCloud = 0;
timeFormat = 12;
}
*/
[preferencesDict setObject: preferenceData.colorScheme forKey:#"shopOpens"];
UPDATE
This is how I finally figured it out, for those who have a similar question:
NSPredicate *filter = [NSPredicate predicateWithFormat:#"aMostRecentFlag == 0"]; // find old records
NSFetchRequest *freqest = [PreferenceData MR_requestAllWithPredicate: filter];
[freqest setResultType: NSDictionaryResultType];
NSDictionary *perferenceData = [PreferenceData MR_executeFetchRequest:freqest];
Disclaimer: I've never used magical record, so the very first part is just an educated guess.
I imagine that preferenceData is an instance of NSArray firstly because the method name uses findAll which indicates that it will return multiple instances. Secondly, a normal core data fetch returns an array, and there is no obvious reason for that find method to return anything different. Thirdly, you referenced using an index operation in your question.
So, preferenceData is most likely an array of all objects in the store that match the specified predicate. You indicated that there is only one such object, which means you can just grab the first one.
PreferenceData *preferenceData = [[PreferenceData
MR_findAllWithPredicate:predicate inContext:defaultContext] firstObject];
Now, unless it is nil, you have the object from the core data store.
You should be able to reference it in any way you like to access its attributes.
Note, however, that you can fetch objects from core data as dictionary using NSDictionaryResultType, which may be a better alternative for you.
Also, you can send dictionaryWithValuesForKeys: to a managed object to get a dictionary of specific attributes.
I am trying to implement a UICollectionView using supplementaryViews.
I use a Nib file to create my supplementary view. Here is the method in the layout to add the supplementaryView:
NSMutableArray *attributesInRect = [[super layoutAttributesForElementsInRect:rect] mutableCopy];
NSLog(#"%#", attributesInRect);
if ([self.collectionView numberOfItemsInSection:0] > 1 && !self.selectedItem)
{
if ([self.musicList count] > 0)
{
UICollectionViewLayoutAttributes *musicViewAttributes = [self layoutAttributesForSupplementaryViewOfKind:#"MusicView" atIndexPath:[NSIndexPath indexPathForRow:1 inSection:0]];
musicViewAttributes.size = CGSizeMake(CGRectGetWidth([[UIScreen mainScreen] bounds]), 150);
musicViewAttributes.center = CGPointMake(musicViewAttributes.size.width/2, musicViewAttributes.size.height/2);
musicViewAttributes.zIndex = 0;
[attributesInRect addObject:musicViewAttributes];
}
}
return attributesInRect;
Don't pay attention to the conditions here, only on the array of attributes (attributesInRect). When I do that, my supplementary is properly added to the CollectionView.
My problem is to retrieve an added supplementaryView. On the NSLog, it seams that my supplementaryView is not listed in the array. In this case I can't check it's existence before adding a new one.
I don't really understand why as the documentation specify:
Return Value
An array of UICollectionViewLayoutAttributes objects representing the layout information for the cells and views. The default implementation returns nil.
According to that my supplementaryView should be in that array.
Any idea about that ?
Is there any way I can validate a value updated in a Core Data entity's property against values of the property in other entities in the collection?
At the moment I create an entity with some default values, add it to arrangedObjects, then get the user to modify the various property values. However, I would like to check a particular property and make sure there're no other entities in the array with the same value for that property. What's the best way to do this?
Many thanks,
Dany.
Manually checking is only a few lines of code with a fast enumeration loop:
BOOL unique = YES;
for (NSManagedObject *obj in collection) {
if (obj.property == value) {
unique = NO;
break;
}
}
I have an SPListItem and I have an array of column names.
When I try to access the SPListItem values using the code below:
for(int i=0;i<arrColName.length;i++)
{
string tempValue = item[arrColName[i]].ToString();
// Works fine in case the the specific column in the list item is not null
// Argument exception - Values does not fall witing expected range
// exception in case the value //is null
}
I think that you used an SPQuery to get the list items and forgot to add the field into the viewfields property of SPQuery.
query.ViewFields = string.Format("<FieldRef Name=\"{0}\" Nullable=\"True\" />", mFieldName);
Usually when you test your program with the farm account the code will work, with normal users you get an ArgumentException.
Another problem/feature which causes ArgumentException is the new ListView Threshold. If th elist you try to access has too many items, this Exception is raised. A way to handle this is to increase the threshold with powershell for the list.
Not only check if item != null but also item["FieldName"] != null. Because if you will try to call .ToString() on null, you will get exception.
And if that field with internal name "FieldName" name does not exist, you will also get an exception. So you would probably try
SPFieldCollection fields = list.Fields;
foreach (SPListItem item in list.Items) {
if (fields.Contains("FieldName") && item["FieldName"] != null) {
string fieldValue = item["FieldName"].ToString();
}
}
I had a similar situation with custom cascade field (or column). I did it following way and it seemed to work for the custom field types.
item.Properties["Country"] = "Mexico"; // custom field
item.Properties["nCity"] = "Cancun"; // custom field
item["Document Descriptions"] = "Test document description.";
Note: I added item.Properties for the custom columns. No need to add properties for built in field type (else they don't work).
Does your array contain the internal names or the display names of the columns? If it's the latter you might try item[item.Fields[arrColName[i]].InternalName].ToStrinng(); instead.
Sharepoint Lists aren't stored as a array with a static size.
You have to use the built in sharepoint iterator to go through each element
For example:
SPList checklist = //Some initiliaztion
foreach (SPListItem item in checklist.Items){
//work
}
This will do work on each item in your SPlist
Edit:
Wrong advice, I didn't see the code until after the edit.
Maybe try a cast?
(String)item[colname]