I have to create a project in iPhone which uses the Tin Can API. The Tin Can API is an advanced distributed learning process.
I have no idea about where to start in Objective-C.
I have read the site http://tincanapi.com.
For implementation, I have some basic questions:
How and to create my own LRS?
How Tin Can API can communicate with my own LRS and LMS with ASIHTTPRequest programatically?
There are two parts to TinCanAPI at play here. I'm suspecting you only need to handle one of them on iPhone. One part is the client-side that sends the statement date to the second part (the LRS server-side). It would be very odd to create the LRS server part on an iOS device, so I'm going with the thought that you need to send TinCan statements from an iOS device to an existing LRS.
An LRS accepts statement data via a REST interface and this data can be POSTed using a standard NSURLConnection or using AFNetworking. There are a couple of options for abstracting all those calls with a library one of which is a new OSS version of the basics appearing very soon from Rustici Software found here http://rusticisoftware.github.io/TinCanObjC/. There is no link for it just yet, but feel free to contact me for more details and I'll update this answer with the link as soon as there is a public link.
For your specific questions:
1.) You can create your own LRS by understanding the spec document and creating the REST endpoints as specified. This is not a trivial undertaking by any means.
2.) Your best bet is to use an SDK or simple GET and PUT/POST statements from AFNetworking to the TCAPI endpoint.
Related
I am programming a Symfony2 App. The structure of my Symfony2 app like:
Login (username / password)
Get Survey for this Login / for this User
User input / click answers. After each click a Ajax request save the answer
User submit survey after answering every question
I have no experience with mobile apps like IOS, Android or Windows. The mobile will created by an other team. The question ist quite common, but which steps i must realize? Are there any literature that you can recommend me?
What was the right way to create an API?
How far Symfony2 supports to create an API for this use cases?
Unfortunately I have no experience on REST, but i suspect this is necessary, right?
I look forward to each answer.
Let me state the obvious first, if you start building a project with technologies you don't know enough about, it WILL be a nightmare. So by all means take your time to learn what you need.
REST is the reccomended standard to build an API since it's native http native and it's quite simple and flexible at the same time. There are tons of simple tutorials on REST, starting from Wikipedia, so I won't link them here.
But I'll tell you a secret, a web service can simply be any web page that reply to your requests with structured data. I.e. even a non-REST series of "webpages" the reply with JSON data can be defined a web service.
By now you see that you can easily do that with Symfony. If you already know how to do stuff and show pages with Symfony, only add JSONResponse to the mix , and also the _format routing parameter, and you should be on a good way.
You just create a path (i.e. an action) for whatever the mobile application needs to do. Of course later on you will learn the beauty of REST and refactor your API accordingly, but first thing you build a working system.
Reading this blog post is a good start. Now if your application will only serve API responses there is the very good Symfony REST Edition which already includes all bundles and tools needed to create an API centric application with Symfony2.
You also have the Lionframe framework but I didn't tested it yet.
Following the Book App example in play 2 for scala, I now have a basic working app.
What I want now is to add some features like
User registration
User authenetication to access some pages
What is the best way to do it in play for scala? Should I manage it by my own? is there a plugin for that?
Note: I'm the maintainer of Silhouette.
I can suggest you Silhouette which is a core only fork of Secure Social with the intention to built a more customizable, non-blocking and well tested implementation.
For the first stable version there are only two open issues which must be resolved. And these issues are only future requests. There are no API changes planed. The documentation must be improved and a sample application is started. The unit tests are also a good starting point.
If you plan to follow the authentication flow as stated by Secure Social then stick with it. It exists since more than two years and it is well tested by many companies. Otherwise take a look at Silhouette.
You have two options:
Secure Social (http://securesocial.ws/)
But it has unusual registration flow, where the user have to enter your email first, and receive link to registration form.
However, there is a pull request that address this issue (https://github.com/jaliss/securesocial/pull/260)
Play Authenticate
It doesn't support Scala out of the box. But there is a workaround created by me here: https://github.com/joscha/play-authenticate/issues/92
Both of them requires you to write the interface layer to database. An important drawback in both of them, is that you won't be able to make use of reactive database drivers like Reactive Mongo. they assume that you will return the results immediately, not a Future of the result.
There is a securesocial plugin (http://securesocial.ws). Covers most common authentication methods, has registration stuff. I found it very usefull.
The drawback is it's documentation. If you want to do something a bit differ from the simplest scenarios - be prepared to read through the source code.
I'm, going to write a web app, which should be CRUD accessible from both, the web and native mobile device apps. For the latter i'm definitely committed to a REST API. Is it possible to realize that with Meteor.com ? Would it be an option to use Meteor for just the web and a second REST interface to directly talk to the mongo? Since the meteor client listens for changes in the mongodb this should not cause conflicts, does it?
As of 2015, look at Gadi's answer for the Meteorpedia entry on REST APIs, and at krose's answer comparing REST API packages. Discussion for folding REST APIs into core is on Hackpad. This question is a duplicate of How to expose a RESTful service with Meteor, which has much better answers. -- Dan Dascalescu
Old answer (2012) below.
For adding RESTful methods on top of your data, look into the Collection API written for Meteor:
https://github.com/crazytoad/meteor-collectionapi
As for authentication for accessing the database, take a look at this project:
https://github.com/meteor/meteor/wiki/Getting-started-with-Auth
Both are definitely infantile in development, but you can create a RESTful API and integrate it with a mobile native client pretty easily.
There are a lot of duplicates of this question. I did a full write-on on this in Meteorpedia which I believe covers all issues:
http://www.meteorpedia.com/read/REST_API
The post reviews all 6 options for creating REST interfaces, from highest level (e.g. smart packages that handle everything for you) to lowest level (e.g. writing your own connectHandler).
Additionally the post covers when using a REST interface is the right or wrong thing to do in Meteor, references Meteor REST testing tools, and explains common pitfalls like CORS security issues.
If you are planning to develop a production application, then Meteor is not an option right now. Its under constant change, and there are still many common features it has to support before its ready to use, which will be quite some time.
For your Question, Somebody has already asked and answered the question about support for file uploading in meteor(also contains HTTP handing related information).
How would one handle a file upload with Meteor?
I am in the process of scoping the development of an iPhone app for a client. Among other things, the app will allow users to browse through and place orders on specific (tangible) products.
The client has a website that currently does a similar thing and due to their limited budget and the fact that the website runs on a third-party proprietary platform which they have no control over, we are investigating possible alternatives to building a web service.
On the website, user registration and authentication, as well as order placing is done through POST requests via secure HTTP. The response is always a formatted HTML page which will contain strings indicating whether the request was successful or not, and if there was an error, what the error is etc.
So provided I can replicate the POST requests on the phone, and parse the HTML responses to read the results of each request, do you think this is an acceptable alternative to building a web service to handle this?
Apart from the possibility of pages changing (which we can manage) and the fact that I will probably have to download and parse a relatively large HTML response, are there any other drawbacks to this solution and is there anything else that I might be missing?
Many thanks in advance for your thoughts.
Cheers,
Rog
You could create an intermediary server that will communicate with the client server, and on it expose some REST web services with json (small overhead and easy to handle) responses that will be consumed by the iPhone app.
So, you're going to parse HTML and formulate POSTs off a third-party server, and pray that they don't even so much as rename a form field.
Your question is in two parts:
Do I think that a miracle is an acceptable solution? I don't.
Do I think that aside from the fact a miracle is required, are there any other drawbacks? None that I can think of.
You didn't ask, but this is a terrible course of action. Two suggestions.
I spy an assumption that the providers of the third-party platform aren't interested in enabling third-party applications by providing an API. They have a very good business reason for this, which is that it promotes platform lock-in. Reach out to their support department and have a talk with them.
You have to sell the client on building an intermediary web service. To at least try to mitigate the damage that changes on this third-party platform can do to your app, I recommend that you build and operate a proxy that receives requests from your applications, and proxies them over to the third-party platform. You should build into this client-server protocol a means for returning "we are in maintenance mode, go away" messages to apps, for that inevitable day when the third-party server changes something that breaks your app (they swapped the billing and shipping address pages, for instance) and you have to rush through an update through Apple to deal with it.
The proxy could be written in something more flexible and easy to bash stuff out in, such as PHP, Python, Perl, or Ruby. It could be hosted at Amazon in a micro instance.
p.s. This question is inappropriately tagged objective C.
HTML is the worst because of parsing (1-2secs per page), memory, and changes, but you already know that. Check in advance that ALL the data you need is exposed on the HTML.
If you use an intermediary server you are moving work elsewhere and you have another server to maintain. I would only do that if memory is an issue. Check How To Choose The Best XML Parser for Your iPhone Project for memory/performance/xpath support. libxml2 is a good option, but it depends on your needs. And maybe you'll want to check ASIHTTPRequest features before using the SDK.
I think utilising the web language of JSON would contribute to the diminishing of the parsing time. By building a REST service that, when sent a GET request, returns the correct information for easy sorting, you could then display the output a lot faster than that of parsing straight HTML.
I prefer JSON over XML, but everyone has their personal preference. You should look at a few very good libraries that are built specifically for parsing purposes of both XML and JSON.
For XML I recommend using the inbuilt libxml parser. Albeit, this can sometimes deem very difficult to use. A simple Google search will bring up a heap of results that relate specifically to what parser should be used depending on what task is to be completed.
As for a JSON parser, I recommend SBJSON. I am currently using it one of the biggest projects I have undertaken and it is definitely working perfectly for my use.
If you need a good way to connect to a RESTful web service, you should try LRResty.
Don't go for a parsing solution on the iPhone for 4 reasons:
Server can change their design and break your application (AppStore submition is long) + They can also detect that the request are sent from an application based on user agent which you have to update the application to change it.
Some of the requests might be made thru Javascript so you not only have to parse (X)HTML but also Javascript request (which can be in the form of XMLHttpRequest, but don't have to)
Long term evolution of the mobile market : maybe your client want (or will want) an application for android, Blackberry, Bada OS (Samsung), Symbian (Nokia/ OVIStore), Java Mobile or Windows Phone 7?
Of course network traffic, Memory and CPU needed to parse HTML (look the time it takes to the browser to do it?)
Regarding the traffic, if the application will not have a huge traffic you can home-host your proxy. Or you can find some provider to host it for you. I guess you won't need more than a couple of Megabytes of storage but maybe traffic. For less than 100€/year you can find some with unlimited traffic (like OVH Pro plan or Infomaniak). But if you want to go Java have a look at Google App Engine : you pay only if your traffic is important and if your application generate many CPU Cycles. If not : you don't have to pay. And it's hosted on Google server : reliable.
If the client is open, you could consider the paypal API.
We have an iPhone application created by an external consultancy that we're planning to add card payment facilities to in a subsequent release.
We plan to host a service ourselves in order to process the payment stuff, with SSL encryption. We have in-house expertese for all of this apart from the (contracted out) iPhone bit.
Are there any specific gotchas that we should be aware of that concern designing web services for iPhones?
We'll be writing the web service in C# 3.5.
JSON data format is better to be converted into NSArray or NSDictionary objects. It's easier and faster to be parsed.
So, specifically for the iPhone, it's a lot better to consume JSON data. Unless if there's some technical complexity that JSON is unable to handle.
Check YAJL:
http://github.com/lloyd/yajl
There are Objective-C wrapper/implementations by gabriel in github and by MGTwitterEngine.
TouchJSON is another code that's simpler than yajl. You can convert JSON string into NSDictionary or NSArray object in 2 lines of code. But, it maybe slower.
I'm not sure there are really any special considerations. The iPhone should be able to communicate with most types of webservice.
I worked on an iPhone app that communicated to a RESTful webservice written in Java.
I imagine it's pretty straightforward across the board - there are plenty of libraries for parsing/generating XML or JSON formatted messages, the iPhone can handle HTTP authentication, HTTPS, caching, etc.
It's just down to your iPhone developer to get it right :)
For SOAP based web services I strongly suggest that you try gSOAP. This library does not support Objective-C, however it supports C and C++ and is certainly the most complete open source project to access SOAP based web service; it also outperforms all of the other libraries.
For Objective-C you may want to try wsdl2objc, but I am not sure if it provides support for SSL/TLS (gSOAP does).
Finally, REST based web services are easily handled using ASIHTTPRequest.