Is there any way we can convert or obtain a Firebase snapshot object (FIRDataSnapshot) as raw JSON, so that it may more easily be converted to models using mappers.?
I would like to know if anyone has serialized a snapshot object to JSON using JSONSerialization, and then using the mappers. Also, are there any underlying implications of such conversions and using it?
Related
Can anyone tell me the best approach to use cache while getting response from api.
I'am using Alamofire '4.7.3' and swift 4.2
You can implement an internal database with CoreData to store your json and when you want parse it to create the objects you want
If you have a JSON response, convert it into a string and save it locally. Parse back the objects using the Codable protocol.
Anyway the best approach would be to parse it into objects and then save the objects into CoreData (or Realm...)
I have a JSON with more or less 75 keys.
I need to receive this JSON and store offline it using Realm.
I do not want to iterate through the keys, since I've heard that there are ways to save a large JSON using a few lines. How can I do this?
EDIT:
My JSON (
I saved on a server away because it's too big)
http://myjson.com/i7e6l
There is no easy, one liner to parse the JSON and store it in Realm, since each JSON response is unique and no framework can have explicit knowledge about the structure of your JSON response without you giving some information to this framework about your JSON.
You will need to write some code either to parse the response or to make a mapping between your JSON response's fields and the properties of your Realm object. If you choose the latter solution, you can use Alamofire Object Mapper to do the JSON parsing automatically, but even then you have to write code for the mapping.
I need to cache json data from API in swift.
So I researched a Lot & get to this Post.
I tried to implement the Option 1 in my App. But the Custom manager always returned nil. I don't know why?
After that I got AwesomeCache. It says that it an do Awesome API Caching.
But I don't know how to implement this?
I referred this Issue. Still I can't figure it Out.
This is how my Current implementation Looks without Cache:
Alamofire.request(.GET, "http://api.androidhive.info/volley/person_array.json")
.responseJSON { (_, _, data, _) in
let json = JSON(data!)
let catCount = json.count
for index in 0...catCount-1 {
let name = json[index]["name"].string
println(name)
}
Please suggest me the Best way to Cache JSON from API ?
Thanks in Advance!
UPDATE
These are my requirements
Fetch the JSON from the API & Parse the JSON data. These can be done with the help of Alamofire & SwiftyJSON
I will populate the parsed data in the Table View. It works when the user is in Online.
But I want to show the data in the Table when the user is in offline too.
So I need to save the Parsed data or the JSON data in my cache & I need to refresh or expire the cache within a week or days.
I don't prefer to store the JSON in my disk because it will be updated.
Please suggest me the Best way to achieve this...
You have many tools already at your disposal.
NSURLCache
All your requests are already stored in the NSURLCache in the NSURLSessionConfiguration on the NSURLSession stored inside the sharedInstance of the Alamofire Manager. Those stored requests already follow all the caching policy rules provided by the servers you are hitting. You can control the caching behavior by setting the requestCachePolicy on your own custom NSURLSessionConfiguration. I'd also suggest you read through this awesome NSHipster article that walks you through the ins and outs of NSURLCache and how to control it.
Creating custom Manager objects is covered in the current Alamofire docs.
Downloading JSON to Disk
You can also download the JSON directly to disk using Alamofire.download instead of using Alamofire.request. This will download the payload to a fileURL that you provide in the destination closure. This would give you full control over the caching of the file after that point. You would need to create your own caching policy around these files afterwards if you wanted to follow the caching header rules provided by the server.
Populating Table View
Once you have your data downloaded to disk, you need to load it into an NSData blob and parse it into JSON to populate your table view. This should be pretty straight forward. You need the destination NSURL that you specified to Alamofire when you started your download. Then load the file data into an NSData blob. Finally, use NSJSONSerialization to convert the NSData object into a JSON AnyObject which can be parsed into model objects to populate your table view.
Obviously you don't "have" to parse the JSON into model objects, but this helps protect your table view from malformed JSON data.
Storing JSON for Offline Usage
If you stick with this approach, you'll need to track your cache expiration dates in something like CoreData or SQLite. You can do this by either caching the paths to the JSON files on disk, or store the model objects directly in CoreData or SQLite. This could get fairly complicated and I would not recommend this approach unless you absolutely don't want to cache your model objects.
Offline Usage
Generally, if you need to cache data for offline usage, you want to store your model objects in something like CoreData. You would use the Alamofire request method coupled with a responseJSON serializer to parse the data into JSON. Then you would convert the JSON into model objects. From there, you'd save your model objects in CoreData, then finally populate your table view with the model objects.
The nice thing about this approach is that you have all your model objects cached in the case that your table view is accessed when the device is offline. Coupling this design with queries to your NSURLCache to see if your request is cached let's you avoid unnecessary server calls and parsing logic when you already have your model objects generated.
Given the updates to your original question, I would recommend this approach.
You can use this cache open source. It cache data on disk and memory. Can cache many swift type, and custom class which inherit NSObject and conform NSCoding protocol.
https://github.com/huynguyencong/DataCache
To implement:
First, it use NSCache for mem cache. NSCache use like a dictionary.
Second, save cache to disk, use NSFileManager methods.
I'm trying work with webservice.And I'm posting username and password with afnetworking.I'm getting this output.It's Ok.But I need the use it with coreData.And how can I keep session in application.
What should I do in this case.
GET: {"result":"active","id":"11","name":"John App","statu":"customer","token":"VE0HRuf33fv6y7lIftJYJVfFtmwaRN"}
You need to parse response to NSDictionary using
NSJsonSerialization
Than you can extract your values using key-value access in
NSDictionary
Setup and create core data model (.xcdatamodel file)
You can use some tools like MagicalRecord for simplify your life
with core data
write to data base and save object.
I just want the RestKit to parse the JSON data into NSDictionary, but not a class. This is because the attributes of the JSON data is dynamic, means the number of fields is not fixed and field count can be large. So I don't want to create a huge class to map the json data. Just keep that in NSDictionary. Does RestKit provide this functionality or we have to work out some other way.Guidance Needed.
Thanks.
Have to modify the Restkit to support the ability ....
RKObjectRequestOperation.HTTPRequestOperation.responseData
then parse the json data to dictionary or array
Either use AFNetworking (which RestKit is built on top of) or use a dynamic mapping (depending on your destination class needs).
If you have large arbitrary data then you should just avoid using RestKit as it will only slow your performance.