I'm working on an iPhone project that needs to receive data from a PHP script during execution. My first thought was to use sockets/streams on either end to connect the two, but I am having trouble finding information on how to do this from the iPhone side.
Has anyone been down this path that could point me towards some useful resources or offer some advice? The official documentation seems to be geared more towards desktop apps and uses code that doesn't seem to be supported on the iPhone (namely NSHost).
Update: The intended use of this app is to receive log messages from an executing script, so I can't use a simple HTTP request with JSON or XML. Many cases will involve the page being loaded by another client, where the script would relay/push log messages to the iPhone.
Polling is evil. You'll chew through batteries doing that.
You might consider running an HTTP server on the iPhone. Check out this blog post; it has an implementation of an HTTP server in Cocoa as well as example code for using it for two-way communication.
The PHP CURL library (can't link it because the site doesn't trust me yet, just search php.net for it) is a (relatively) simple, easy way to make http requests with a PHP script.
Why don't you just use HTTP? Create an ad-hoc protocol with XML or JSON, use POST for upstream data transmission. I'm a fan of JSON for this sort of thing, personally. The PHP, instead of returning a webpage in HTML for rendering, should just return your data in a JSON format.
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I'm not sure this question is appropriate here but I hope I could get some help. What i'm looking to do is basically to make a server based iPhone application. I've got an ubuntu server ready to be used. I'm thinking of making a web service which my application then can use but I have virtually no experience in this field so i'm looking for some help to get pointed into the right direction, what language to write the web service in etc. It isn't required to be a web service but anything that make's the iPhone app depending on the server.
This little mission is simply for learning experience.
Probably PHP is what you will use to write the webservice. REST based services are the most popular, but it could be as simple as a form POST passing in parameters. The PHP script (no matter which way you write it), will then pass those parameters and any other needed info to a server method that either executes a SQL query (preferably using a stored procedure) or uses some other server resource. That data would then be output via the webservice as either XML or JSON (I personally like JSON better).
Check out Ray Wenderlich's tutorial on just this kind of thing:
When it comes time to handle the request in iOS, my personal choice is AFNetworking. It uses blocks instead of delegate methods and is blazing fast. I can hook you up with examples if needed.
Ok, First you need to learn how to write web services in PHP. Which will return you response in XML format. I personally prefer .PLIST format because it gets easier to parse on the iOS.
Once your web services are up and running. You need to use NSURLConnection and NSURLRequest to talk to your web services. Implementing the NSURLConnection Delegate methods correctly, you can download your XML response, maybe save it in a file on your Documents Directory.
Then once done downloading start parsing that response using NSXMLParser. implementing the delegates and what not, you can create your data structure the way you feel comfortable with manipulating it and store the parsed results in them and populate your View accordingly.
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.
I have a WSDL service that is working fine with .NET using HTTP POST Bindings, rather than using SOAP. The HTTP Post request returns the raw XML for the objects etc. removing all the overhead of SOAP.
I would like to use this within the iPhone. I have located the tool at wsdl2objc tool (http://code.google.com/p/wsdl2objc/) however it seems to only generate SOAP bindings which I don't use because I don't need the overhead.
What would be the best option for using WSDL HTTP POST Bindings within the iPhone OS? It would be great if the wsdl2objc tool also supported the HTTP POST bindings however I don't see that happening soon. I would rather have this code automatically generated for when the service changes etc.
Any ideas would be greatly appreciated.
It seems that there are very few code generators around for this kind of thing. For now I lumped with wsdl2objc but shrunk the size of the data being returned from the web service in a bid to make the XML smaller and more manageable. On a slower cellular connection that the iPhone sometimes has (2G etc.) I noticed slight improvement, but nothing worth an awards evening.
I have a fair bit of experience working with the iPhone SDK. I have a couple fully developed apps including a utility application for tracking data and a board game. I would consider myself a novice on the iPhone SDK. I also have no issues with reviewing documentation and examples for hours until I understand something, as long as the documentation exists and makes sense.
I am not however an expert at XML documents and parsing attributes and creating documents. I have written in the past PHP code to access web services and complete transactions via SOAP XML messaging. I need to do a similar application using iPhone SDK. Here is what I need.
1) Create XML messages to send to a SOAP service
2) Receive XML messages from a SOAP service
3) Parse the XML response messages into a custom object
All of the URL and SOAP part is relatively straight forward. Where I start to get discouraged is the area of creating and parsing the XML messages. Using PHP these tasks are very simple as the language has built in SOAP clients and you can easily class map objects to SOAP messaging and the heavy lifting of the XML processing is just taken care of automatically. I have considered writing a proxy PHP service and simplifying what is needed on the iPhone side but this just complicates what I want and adds a dependency on another app to work in conjunction with the web service I'm accessing.
It seems that in the iPhone SDK or objective-c in general you have to be a pro at the construction and the parsing of XML messages on your own. I am really discouraged at the idea of creating tons of custom code to parse each message element by element. I've taken a small look at TouchXML / KissXML and I am not thinking they are what I need.
The real key objective here is that I want to easily receive an XML message and some how get the elements and their values copied over to an object. How can this be done without hours of writing parsing classes and understanding all of the guts of creating XML documents?
I have used Matt Gallagher's XPathQuery to great success on the iPhone. It's simple and straight-forward.
I've found, though, that the messages I have need to parse are drastically simpler than what XML (and even his simplified parser) is capable of. I've modified his source to return a data structure that's much easier to work with -- instead of having keys a bunch of keys (nodeName, nodeContent, nodeAttributeArray, attributeName, ...) for each node, I simply create nested arrays and dictionaries with the node name as the key and the content as the object directly. I completely ignore attributes, and I only use arrays if there's more than one node with the same name. Here's that code. Note that it's only been tested on the XML that I care to work with. :)
Edit: whoops, I just realized you're also looking for XML creation. This just does parsing. I'll leave it here as a partial answer.
It seems like what you really want is this:
http://code.google.com/p/wsdl2objc/
As it will create objects for you from a WSDL, and provide support code to send/receive them.
However what is mostly happening, is that people are not using SOAP for mobile web services, but instead are going to RESTFUL approaches.
That includes posting form data in HTTP POST requests or querying via GET, then getting back either JSON or plists which turn into dictionaries (JSON is more widely understood by server developers BUT you have to be more careful to correctly define the structures being passed, since you can do things like have a dictionary with the same key repeated... plists are more robust in that you can't really build anything "wrong" but is less standard on the server side).
If you have to use SOAP though, WSDL2ObjC is probably going to save you a lot of mapping.
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.