I need some help with a CouchDB iOS project.
I'm using Apache CouchDB Server and the couchbase-lite iOS Framework.
On my CouchDB I have a template document.
- CouchDB Server
- database
- template
- document 1
- document 2
- ...
My goal is to only synchronise my iPad with this template document to get the latest data which my application needs.
But when I enter some data on my iPad, I want that this data should be pushed only to couchBase Server.
How can I "tell" my application to synchronise only one file and not the entire database with my server and at the end how can I "tell" my application to only push the data that is input from user side ?
More importantly, Do I need two databases on my server? One for the template and a second one for user input data?
If YES, then I just need to know how I can only push my data.
Guidance needed. Thanks.
This is how I solve this:
I tend to add a 'last update' date to all my documents, and store this in a format that means they'll be sorted in time order (epoch or yyymmddhhmmss) both do.
Create a view that uses the update time as a date.
On your client, store the time since you last updated.
When you update, access the view with a startkey parameter set to the last update date.
You can then either use 'include-docs=true' to get the documents as you query the view.
I tend to use 'include-docs=false' though as it means when a lot of documents have been updated I transfer less data in a single query. I then just directly access each document id that the view returns.
Related
I have an application which uses the data from web server. When you first launch the app, it downloads the data and then work with it. But what if the data on web site was changed. How can I know from the application that the data was changed, and if so, what data should I download?
My first idea was each time when you run the application to check the number of entries in the local database on your phone and the number of entries on web server, and if they are not equal, delete all data in local database and then download all data again. But I think that it will take more time than if the application just loads 5-10 needed records instead of all data.
The second idea was when the information on the site changes, website somehow has to inform the application to load some records. But I don’t know if it is possible to do(
Another idea was to compare the id of the last entry in the application database with last id on website. And if they are not equal download the information from the next id.
Are there any suggestions how can I accomplish this?
I am not sure that you have any database or web services but my suggestion is parsing data from the web with JSON or XML.
https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSXMLParser_Class/
this class reference is will be clear for you.
Also in my opinion, if you are new in swift and want to choose easy way for this operation search for iOS package managers.
If you want to use a package manager for your project, e.g Pod
https://cocoapods.org/pods/Alamofire
would be a good startig point.
Alamofire is an HTTP networking library written in Swift.
Hope to helped you
I have a database of many users,which i want to store on both locally and on my server.Whenever user updates any information,i successfully updates it in local database using core database. But how to change this information into the server?? I am not getting this please help?
I thinking of sqlite file to server every time user updates his information. but how to send data of sqlite file to server?
Add a column to your local DB that is the last time updated. (I think there may be a way to get SQLite to fill this in semi-automatically for you, but even doing it "manually" is no big deal.) Then, when you want to upload updates, query for rows updated since the last upload. Ship to the server as JSON records.
You can also keep a separate table that tracks updates, but that's for more complex scenarios.
You have to use some tactics for this. Here is a short explanation of this work.
Database Structure
Web service
You have to design database at local and server side and manage flag(Bool) and update time.
Like when you launch app then you have to check your local data and take last update date and send request to server what's new update after this date. If there is any update then you can send data as a result of that webservice and handle that response at local device.
When you do some changes at local device then you have to manage flag, update time and created date. flag will show it has update on server or not. If updated then Y otherwise N. And you have to send created and updated date with this.
During this request you have to manage in a same timezone. You can use standard UTC timezone because there may be chances that User can switch in different timezones so handle this.
If you need more clarification then you can ask at our chat room https://chat.stackoverflow.com/rooms/43424/coders-diary
This approach definitely work for you.
My app talk to webServer. At login, I pull down JSON and make up CoreData with 4 Entities (about 1000 rows each). The data changes on Server, So with every login, I have to update my existing CoreData.
What is the best approach to find out if records exist and insert new ones if need be?
To be smart on update (not blindly update every time), you need some intelligence on the server side.
One idea I would do.
Server has master table that records the timestamp of modified date of the 4 entities. It also has API to expose the master table. Every time change occurs to one of the 4 entities, master table's corresponding entry has to be updated as well.
You create the same copy of master table in application side as well.
On application launch, you query API in 1. and compare with the value in 2. to see if the timestamp has updated on the server side.
If YES, then download and replace the corresponding entity.
Another one which allows finer control.
Add timestamp column to the 4 entities on the server side. Every time entry is added/updated, the timestamp is updated.
Prepare an API for each entity that filters only newer items than the specified timestamp
On application launch, you query API in 2. and update.
The hole of the second approach is that it cannot handle deletion on the server side. Maybe you can combine something like the first approach to support this.
We are trying to create an iPhone application that will automatically receive data from a database. Which is a database that will work with Xcode. Our goal is that users can go to our website and input information. That data will be recorded to a database. Once the user downloads our app, the info should then be retrieved from the database and included in the app. We are wondering what database is suitable. It must be able to receive information from a website AND submit it to an application.
You're unlikely to find a iOS "aware" database that can automatically sync content over the internet.
However, you can of course obtain the data over the internet yourself and then insert it into the local database on the device, in which case the popular (and supported out of the box) SQLite would seem like an obvious choice.
As #Deepak also suggests, you could use Core Data which is a (sort-of, ish) ORM that can automatically use SQLite as it's underlying storage mechanism.
The solution that most people use in this case is to use an RDBMS like MySQL and build a web-service layer on top of the database for the entities that your iPhone app is interested in.
This way, when a user goes to the web-app, they can add the data that you allow them to add there, and later on they can access the same data from the iPhone app via the web-service layer also.
Couchbase's new iOS-Couchbase framework is in beta right now - all the functionality of Apache CouchDB on your favourite developer platform - at https://github.com/couchbaselabs/iOS-Couchbase. the iOS release is new but we're looking for it to go places!
Its awesome sync abilities would allow you to pull down any relevant content from your website via HTTP/JSON, or further formats using shows and lists if needed. Pushing data the other way is just as easy. Sync can be continuous, or on demand, bidirectional or one way.
Take a look at some of the Couch App frameworks (not for iOS but for your website)
http://techzone.couchbase.com/community/articles/couchdb/recipes
http://www.mail-archive.com/user#couchdb.apache.org/msg13928.html lots of comments on this thread
A+
Dave
I'm developing an iPhone app that uses a user account and a web API to get results (json) from a website. The results are a list of user's events.
Just looking for some advice or strategies - when to cache and when to make an api call... and if the iPhone SDK has anything built in to handle these scenarios.
When I get the results from the server, they populate an array in a controller. In the UI, you can go from a table listing view, to a view of an individual event result - so two controllers share a reference to the same event object.
What gets tricky is that a user can change the details of an event. In this case I make a copy of the local Event object for the user's changes, in case they make an error. If the api call successfully goes through and updates that event on the server, I take these local changes from the Event copy and set the original Event object to match with setters.
I have the original controller observing if any change is made to the local Event object so that it can reflect it in the UI.
Is this the right way of doing things? I don't want to make too many API calls to reload data from the server, But after a user makes an update should I be pulling down the list again with the API call?
...I want to be careful that my local objects don't become out of sync with the remote.
Any advice is appreciated.
I took a similar approach with an app I built. I simply made a duplicate version of the remote data model with Core Data, and I use etags on the backend to prevent sync issues (in my case, it's okay to create duplicate records).
It sounds like you're taking a good approach to this.
Some time back, I developed an iOS app where in, I had almost same requirement to store data on server as well as locally to avoid several network call and also user can see their information without any delay.
In that app, user can store photos, nodes, checkIns and social media post and with all this data, app can form a beautiful timeline. So what we did was, we had everything locally and whenever user phone come in some WIFI zone, we start uploading that data to server and sync both (local and remote) databases.
Note this method works well when only one user can access this data.