My object from app, syncronize with server every 5 min. And user can check his items in web. I generate for him the following link:
"http://mydomain/items/\(self.appDelegate.UUID.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!)/\(items.objectID.URIRepresentation().absoluteString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!)"
UUID - this is device or icloud key.
So the link looks like:
http://mydomain/items/15FDA6B3-C51A-4057-8F98-0143981CC5C8/x-coredata://60DD8665-3136-4CF0-9FD3-FF9164FC7327/Items/p1
But can i cut x-coredata://60DD8665-3136-4CF0-9FD3-FF9164FC7327 to this: /Items/p1. Does it will be unique ?
Or any other ideas how to make look better item id.
Yes maybe better create own id, but i found another solution:
let id = Item.objectID.uriRepresentation().absoluteString.components(separatedBy: "/p")[1]
And result will be integer value.
Related
In swift using Firebase, with:
let ref = dbLocations.collection("Data").document()
ref.setData(data)
Data added with a document Id like 40rprS6NshDHhZiI8YxJ
how can I generate an ID as "location1" "location2" or something but with the guarantee the is a unique one on the database?
If you want to set your own ID then you just have to specify it in document() as shown below:
let ref = dbLocations.collection("Data").document("CUSTOM_ID")
ref.setData(data);
This however will overwrite the document if it already so you must check if document exists before writing data. You could use .setData(data, merge: true) so if document exists it'll update it instead of totally replacing current data if that suits your requirements.
How can I generate an ID as "location1" or "location2"
Using sequential document IDs is considered an anti-pattern when it comes to Firestore:
Do not use monotonically increasing document IDs such as:
Customer1, Customer2, Customer3, ...
Product 1, Product 2, Product 3, ...
Such sequential IDs can lead to hotspots that impact latency.
So you can create your own unique IDs, as long as you are 100% sure that those IDs are unique.
Moreover, each time you call .document() without passing any argument, a new document ID is generated. If you need to have a custom ID then you should consider using:
let ref = dbLocations.collection("Data").document("idOfYourChoice")
I am currently setting up my realtime firebase database to my iOS application.
It is my first time trying to structure user data in a firebase database, and I am really, really struggling with understanding a few key things.
A bit of context to my application's database needs:
When a new user is created, the attributes assigned directly to the user are:
Age
Email
Username
Nationality
Later on, the user needs the option of creating personal diaries!
Each of these diaries being arrays/lists of objects... Where each object in a diary furthermore holds a few attributes in a list/array.
After reading everything I could find anywhere, I picture my database something like this:
I am terribly sorry if it becomes too specific - I will try to make the question as open as possible:
My question is:
How to create the different "children" programmatically and how to find the keys leading back to them, so I can refer to them at other times again? (when editing an attribute in a child).
A few methods I have tried:
setValue([ArrayOfObjects]) --> This creates the desired array, but I can't seem to find e.g. index 3 in this array, to allow user to change his/her email later on.
childByAutoID() --> This as well creates my array, but gives several other problems: User can only store one diary, still can't find the paths to specific indexes...
setValue(), andPriority() --> Can't seem to make the priority function. (Is this function also outdated??)
And a few more...
If anyone can tell me how to achieve just the first few steps in setting up my database structure, I will be forever grateful - I have spent literally all day on it and I am not moving forward ...
Or, at least tell me, if I am on the right track regarding my desired setup of the database. Is it flat enough? Is there a smarter way to store all these user created lists?
Thank you so much! :-)
I don't know Swift so my examples are in Dart but the methods are similar I believe.
First off, I would split the Users node into two. One to hold the user data, which is normally pretty static, and the other to hold the diaries. You would use the same uid key as reference to both. This way you have less nesting to worry about and therefore it is much easier to CRUD the data. If you are using Firebase to authenticate your users then I would use the unique key that Firebase creates for each user as the keys for these two nodes.
Then...
To create a user data node record the Dart code would be something like:
referenceUserData.child(<authenticated user id>).set({
"age": <age value>,
"email": <email value>,
"name": <name value>,
});
To create a user diary node object record the Dart code would be something like:
referenceUserData.child(<authenticated user id>).child(<diary key>).child(<diary object key>).set({
"object info value 1": <object value>,
"object info value 2": <object value>,
"object info value 3": <object value>,
});
You could also create all the object records at once by writing them as a List (array) using .set().
You also need to decide what your diary key should be. You could use Firebase to generate a unique key by using .push().set().
To read eg. the user data then your call could be:
referenceUserData
.child(<authenticated user id>)
.once()
.then(
(DataSnapshot snapshot) {
print(snapshot.key);
if (snapshot.value != null) {
print(snapshot.value);
<code to process your snapshot value>
}
};
BTW, 'priority' is legacy from the early days of Firebase RTDB so I wouldn't try to use it.
What would be the best way to uniquely identify an MSConversation when developing an iMessages application?
In my case I want to give to a game object an ID of the conversation where it belongs to.
Take the localParticipant ID, add to it the remoteParticipants ID ;)
Something like that :
var conversationID = yourConversation.localParticipantIdentifier
for participant in yourConversation.remoteParticipantIdentifiers {
conversationID += participant
}
EDIT:
As noticed in comments, by doing so, you could end up with a very long ID. So the idea is to apply an hash to it, to have a constant size (MD5 is suffisant, we don't need something secure here). If it is still too long, you could crop that hash, but be aware that in that case there is a small probability for two conversations to have the same ID (depending on how much your crop).
The current top answer has a corruption issue in that if a new person is added to a group chat (or if someone is removed) your hashed ID will change.
A more elegant solution in my opinion is to just create your own serial number at the time of the first message being created and add it as meta-data to your message itself. (Using NSURLComponents of course). Then just grab that anytime a message is opened (thus launching your message app) and use that ID. Just keep it in the header of any message sent/received.
But, it depends on what you are trying to do really. The solution I've provided is great for turn-based multi-player games. It might not be good for other scenarios.
I am using Entity's Object ID in order to uniquely identify local notifications and modify them. I observed that first time when I save my entity, it has following object ID:
<x-coredata:///Task/tE1C5A230-A419-42D5-AF78-3327A09D13BD2>
If I don't exit my application, and try to modify notification, object ID doesn't change and I can modify my notification.
Now, if I restart my app and try to access that entity again, it has different object ID:
<x-coredata://D6703834-ECB4-487B-84F8-330A215E16B7/Task/p13>
So I can't modify notification, as object ID for entity is different. Interesting thing is whenever I access that entity, Object ID remains same as the last one.
So my Question here is why Core data shows different object ID for the first time entity is created? When I try to access entity after opening app again for many times, the object ID (different than the first one) remains constant. I am curious to know why is it happening so?
Please note:
I know there are many posts on SO pointing out that using Object ID is not a reliable approach. Still I want to know reason that why two IDs are being shown.
the first OID is a temporary OID - a temporary id denotes objects that have not been saved yet. the 2nd id is a permanent one and is assigned to a MO AFTER it has been saved:
so...
var objectID = object.objectID
if objectID.temporaryID {
object.managedObjectContext.save() //try do catch left out
}
objectID = object.objectID
assert(objectID.temporaryID == false)
I am building an application that I will need to distinguish the Google Contacts from each other. I am just wondering, as long as google sends contacts as First Name/Last Name/mail.. etc (Example) without a unique ID, what will be the first approach to distinguish each contacts?
1) Should I create an ID based on the user's fields? -> by a minimal change, it can break down.
2) Should I create an ID based on First Name + Last Name? -> but most people can have duplicate contacts on their page, would that be a problem? Or married contacts, which can create a little mess.
The reason I am asking this I am trying to create relations and I need to store the data somewhere like that [person=Darth Vader, subject=Luke Skywalker, type=father(or son)], so I need a fast algorithm that can make a mapping for each contact and retrieve the related contacts fast.
I believe they do send back an ID. From the return schema:
<link rel='self' type='application/atom+xml' href='https://www.google.com/m8/feeds/contacts/userEmail/full/contactId'/>
You could use the full HREF value as the ID, or parse out the contactID from the end of the URL, whichever you like better.