How to read and write XML on a web service with iOS - ios

I'm working on switching an iOS app over from storing data using archiving to accessing XML files on a web service, in order to have one central database for many users. I've found resources explaining how to use NSXMLParser, but very little that explains how to create or edit XML files on the database with information entered into text fields on the app.
The web service is up and running, but the Catch-22 is that I can't verify that my parser works properly without also being able to enter data and having it save to the web service.
The data is pretty basic. For example, I might have a Car object that has a few NSString properties- year, make, model, color, and so on. I need to be able to add and delete Cars, as well as edit the properties. Suggestions?

In terms of reading the data, I recently wrote a simple XML parser for iOS called ConiferXML. You can check it out at GitHub. If this doesn't work out there is also another library on GitHub that is a little more complex but does the same thing.

Related

Best design pattern to handle iOS Application State/Data

I am starting a new project (learning purposes) and I am trying to figure out what is the best software design pattern to use in the following scenario.
I have several data that need to be downloaded from multiple webservices and store somewhere in my app, to display it later. However each piece of data (e.g. list of teachers, students) will only be used in one or more specific view controllers (e.g. teachersViewController and studentsViewController).
I read that the Singleton pattern or use the AppDelegate to store a variable (an object like ApplicationData) is a bad practise, even more in this example which I want to restrict the data access.
So, which design pattern should I choose? I have read something about dependency injection, but I don't have any clue about it or if it even helps me in this question. If it helps, some examples with explanation would be nice.
You need some sort of database to store downloaded data. Good choices are Realm and Core Data. The right way to process data is:
Check if data is already in DB and show it if available.
Download or update data from server and parse it to objects.
Save objects to DB.
Show data taken from DB to user.
Download data as needed. When you open VC with students then download only students data and so on.
EDITED: If you need all the data on app open then load it and put in a DB before first screen opens. Then just use DB to show data to user.

Where to save my iOS app's save files

I am learning iOS file system to store my game data like saving the amount of money earned and things like this in a xml file.
The question is where should I store them?
I read this: File System Basics
And I don't know that I should save data in Documents directory or Application Support directory.
Because the data I want to save is something that is not associated with user's documents and user will never see it so it should be in Application Support, but on the other hand it's something that is affected by user interactions so it should be in Documents.
I think it is the Application Support/MyGame as per the Apple Developer guide link shared by you. You are confused by the fact that it should not be something affected by user interaction. Actually it means user should not directly interact with these. See this from the link: File System Basics
Using something like Parse may slow down your app as it needs to interact with their server, but you do get a backup.
For something of this size, I'd use a mobile backend solutions provider like Parse or Firebase. Personally I use Parse in my projects and is very easy to implement advanced functionality into your apps like user registration/save data to users.
Hope this helps.

Where to store user settings in Electron (Atom Shell) Application?

I can't seem to locate a built in mechanism to store user settings. I was hoping that electron provided a standard method for storing user settings across all desktop platforms. If there isn't a precedent for this I can implement it myself, I just didn't want to jump to a custom solution immediately. Research online is pretty sparse in this area. Thanks!
Each platform has different default locations for different kinds of data. So, if you want to store data in default locations based on platform, check out app.getPath(name)
It retrieves a path to a special directory or file associated with name.
You can also use it to differentiate between data the user wants to save, and data your application saves that you don't want to clutter up users directories.
Or if you just want to store files reletive to a specific path you can use the
app.setPath(name,path)
I've faced this particular problem with my Electron app and this post inspired me to write an NPM module called electron-json-storage.
This module allows to easily write/read JSON to/from app.getPath('userData'):
const storage = require('electron-json-storage');
// Write
storage.set('foobar', { foo: 'bar' }).then(function() {
// Read
storage.get('foobar').then(function(object) {
console.log(object.foo);
// will print "bar"
});
});
Electron doesn't give you anything out of the box for this. However, Electron does give you a method for getting the idiomatic location of storing user data in a cross platform way via the app.getPath API.
I'd say the 3 most common ways to do this are:
localStorage (or any HTML5 storage API)
flat JSON file (this is what I do, and I use electron-store for it)
embedded database like IndexedDB, neDB, or sqlite
Which one you choose will depend on your app's needs. If you only need to access this data in the renderer process, then I'd just use localStorage. Most of the time it seems you need to access the data in both the main and renderer, so a JSON file makes sense. If you're dealing with lots of data or complex querying, then maybe a database makes sense. I wrote about this more in detail here.
How about LocalStorage? If you need to access these settings from the browser process, you probably need to write your own (or just use a node.js library that implements this)
The best way that I have found is to store it in a simple file as JSON. The problem is that if you store that JSON in the app dir, then when you update the app, it will get wiped out. So you want to put it in the default directory for user settings for the current operating system. LUCKILY!!!!! There is a library for node developers that will help you find the userdata directory. The module is called appdirectory, and I have used it several times. It is extremely easy to use.
See APPDIRECTORY HERE
One could store data in cookies; Electron has a mechanism for it (https://electronjs.org/docs/api/cookies) and the cookies can be retrieved in the browser (Angular: https://docs.angularjs.org/api/ngCookies/service/$cookies, React/Other: https://github.com/reactivestack/cookies)
I was able to get it working with Angularjs.

Core Data Sync With Multiple Users

I would like to sync a core data app with a user with a different iCloud ID and I am trying to figure out the most graceful way to do this. I do not want the data to sync with all users, but want to be able to sync among family members for instance. From the research I have done, I do not think I can do that using iCloud Core Data sync because it only syncs between devices with the same iCloud ID. I have looked at this stackoverflow answer and read a little bit about Ensembles, Parcelkit and TICoreDataSync, Parse etc., but it is not clear to me if any of those options will allow me to sync with multiple users. Does anyone have a good method for syncing a Core Data app with multiple users?
Ensembles and TiCoreDataSync might work. They can use Dropbox file syncing, so in principle they should work with Dropbox shared folders. I don't think these are the main intended uses, so I suggest contacting the developers and/or doing some good testing yourself before assuming this would actually work.
You'll need to think about the user experience, though. At a minimum, your users would both need Dropbox accounts and would have to set up a shared folder before beginning to sync data this way.
Parcelkit probably won't work. It uses Dropbox's data store API which, unlike other Dropbox services, doesn't appear to support shared data.
Services that do support this kind of sharing exist-- for example, Parse and Firebase-- but make sure to review their pricing carefully before using them. Also of course, there have been any number of projects that have their own custom server back end, but that obviously requires having someone on the team who can do that kind of work.
You need to think about other device types (Android at least) if you want your application to be reaching more users.
I'm doing the same now by the following way:
Setup an online database with proper web services (careful with implementation for security matters - DB should NEVER be exposed by anything other than the web services).
Create a Class for your communication with the server (using Class methods with security handling like authentication and authorisation).
Use the class in your app to communicate with the server (SQL operations are done on the server).
To integrate with CoreData you need to create the model in your app similar to the structure in the backend database. Then you need to create a similar class for the app that deals with only local CoreData.
A higher level class might be required if you want to make sure that operations done on both server and local data storage.
Besides, you have to implement a lot of conditions to make sure that data written in local ONLY after making sure that it is stored online (or create an engine for differed operations to run later).
Another Way if you are familiar with notifications:
Use structured notifications between devices for data operations in order to keep everything in sync with other users. The problem with this is the "Autonomy" of the operations. If two operations were done in approximately the same time, you have to find a way to make sure the order of the operations is done properly (maybe timestamp or something).
I'm looking into the same thing for my app and I 'think' you can do a fairly unsecured version of what you are after using using the public folder in cloud kit as mentioned in this question (no accepted answer at time of posting) : Private data sharing using CloudKit
You would need to find a way to differentiate between data that is truly public and those shared among the users you need and some level of authentication.
I'm going to try exporting a permission file with access permission in it to whomever I want to share with combined with a unique identifier located in that permission file.
Keep in mind, as mentioned in the comments of the linked answer, my implementation will be security by obscurity (thanks for that phrase) unless you find a way of adding proper validation to it but my data is relatively insensitive.
Hope this, or any ridicule in the comments, points you in the right direction : )

How many ways to share data among activities in monodroid?

I need to share some sensitive data among activities.
I have two EditText which are basically username and password
I am consuming a webservice which on the base of provided username and password return some user info (DataType:String). Like userid,useremail etc.. which is basically in CSV format
I need these piece of information throughout my application.But i can't figure out which is the better way.
-- One way i could found out so far is to use sqlite with MonoAndroid
-- Other way i found out is using Application class
I just started to learn android today , but i want to know if there are some other ways to share data ?
As you mentioned, a global Application class and the database are two good ways to share application-wide data. One thing to be careful with is that your Application class could be recycled when the app is in the background, so you would lose any data that hasn't been persisted to something more permanent.
In addition to the database, you can also persist data down to the filesystem as well. This recipe from Xamarin has an example of writing directly to a file. Most of the classes you'll need to do file access are found in the System.IO namespace. Mono for Android also supports isolated storage, which provides a higher level API for reading and writing files.
If you simply need to pass data directly between activities, you can do so by adding it as an extra to the intent. This recipe explains how to do that.
If you want to wrap up access to a particular resource in a more managed fashion that can be accessed by either other parts of your application or even external applications, you can look into implementing a content provider. Android itself provides several built-in content providers for resources like contacts and media, if you need an example of what it's like to use one. This recipe explains how to read from the contacts provider.

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