Save eventually on PFObject with PFFile (Parse

问题:

Goal

I am trying to save a PFObject that has a PFFile as an attribute. I am using the new Local Datastore for iOS, so I would like to save this PFObject with the saveEventually() method.

The Problem

The problem I am encountering is that the saveEventually() method doesn't seem to like saving the PFFiles. I tried to saveEventually() my object without any PFFile attached, and that worked fine. As soon as my PFFile was reattached, Xcode threw a couple of breakpoint notices (errors?) but did not terminate the app, and it appears as though all went well - however a check on the Parse Data Browser confirms that the save did not go through.

Prior to the Local Datastore feature I don't believe this save would have been possible - it would have thrown the "Unable to saveEventually a PFObject with a relation to a new, unsaved PFFile." error. It seems as though the Local Datastore feature has fixed this, as it states in the iOS Local Datastore docs:

"Pinning a PFObject is recursive, just like saving, so any objects that are pointed to by the one you are pinning will also be pinned. When an object is pinned, every time you update it by fetching or saving new data, the copy in the local datastore will be updated automatically. You don't need to worry about it at all."

I have updated the SDK to the latest version (v1.6.2). Any ideas?

回答1:

PFFiles still don't support saveEventually see here

That page was last updated : 2015-01-23

You could pinInBackgroundWithBlock and if successful save the PFFile to a temporary folder in you app bundle and delete it when necessary or unpinned

回答2:

I just released a class which allows to saveEventually a PFFile.

You can find it here :

/*
     This example uses an UIImage, but this works with any file writable as NSData
     We begin by writing this image in our tmp directory with an uuid as name.
 */
UIImage *nyancat = [UIImage imageNamed:@"nyancat.jpg"];
NSData *imageData = UIImageJPEGRepresentation(nyancat, 0.5);

NSString *filename = [[NSUUID UUID] UUIDString];
NSURL *fileUrl = [PFFileEventuallySaver fileURLInTmpWithName:filename];

[imageData writeToURL:fileUrl atomically:YES];

 /*
     We create a PFObject (you can pass an array to below function if you need your file to be saved on several objects). If upload works on first time, do what you want with your file, like linking it on your PFobject.

     If saving fails, it'll be retried as soon as network is available, on this session or nexts launches of app.
     In that case, the pointer at key kPFFILE_MANAGER_OBJECT_FILE_KEY of your PFFObject will be set with the PFFile, then saved eventually within PFFileEventuallySaver
 */
PFObject *object = [PFObject objectWithClassName:kPFFILE_CONTAINER_OBJECT_CLASSNAME];

[[PFFileEventuallySaver getInstance] trySaveobjectAtURL:fileUrl associatedObjects:@[object] withBlock:^(PFFile *file, NSError *error) {
if(!error)
{
    NSLog(@"[First try, network is fine] File saved, saving PFObject");

    object[kPFFILE_MANAGER_OBJECT_FILE_KEY] = file;
    [object saveEventually];

    NSLog(@"Try again disabling your network connection");
}
else
{
    NSLog(@"No network, connect back your wifi, or relaunch app. Your file will be sent");
}
} progressBlock:^(int percentDone) {
    NSLog(@"[First try, network is fine] Sending file %d/100%%", percentDone);
}];