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POHow do I share one UIManagedDocument between different objects?
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  1. POHow do I share one UIManagedDocument between different objects?
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    copied!<p>I've already taken a look at <a href="https://stackoverflow.com/questions/9204025/how-do-i-create-a-global-uimanageddocument-instance-per-document-on-disk-shared">How do I create a global UIManagedDocument instance per document-on-disk shared by my whole application using blocks?</a> but I don't really get it.</p> <p>What I want to achieve is that there should be only one UIManagedDocument - a core data database - for the whole app. Different Objects should be calling a method and get the one and only UIManagedDocument.</p> <p>I use a helper class with a class method:</p> <pre><code>+ (UIManagedDocument *)getsharedDatabase:(NSString *)databaseName { NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject]; url = [url URLByAppendingPathComponent:databaseName]; // url is now "&lt;Documents Directory&gt;/&lt;databaseName&gt;" if (![[NSFileManager defaultManager] fileExistsAtPath:[url absoluteString]]) { // does not exist on disk, so create one UIManagedDocument *managedDocument = [[UIManagedDocument alloc] initWithFileURL:url]; return managedDocument; } else { UIManagedDocument *managedDocument = **?????** return managedDocument; } } </code></pre> <p>As you can see by the question marks, I don't know how to get the existing file. I checked the UIManagedDocument class reference but couldn't find it.</p> <p>Can you help me, please? Many thanks in advance.</p> <p><b>EDIT</b> I was wondering ... what about a singleton method such as:</p> <pre><code>+ (UIManagedDocument *) sharedDatabase { NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject]; url = [url URLByAppendingPathComponent:@"databaseName"]; // url is now "&lt;Documents Directory&gt;/databaseName" static UIManagedDocument *managedDocument = nil; static dispatch_once_t mngddoc; dispatch_once(&amp;mngddoc, ^{ managedDocument = [[UIManagedDocument alloc] initWithFileURL:url]; }); return managedDocument; } </code></pre>
 

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