I'm new in objective C and I'm having problems to find this.
My app is going to be: 1) user introduces a parameter, and 2) my app returns the data in a list.
I have to do this using a website, but i don't know how to know do the request, and then how to pick up and parse the info.
How can I start??
I think that you can handle the filter parameter in the server with a cgi or php, in the app, make the request and get the response.
1.- Get the parameter from the user like a NSString.
2.- Create a NSURL from the string (and the server adress string).
3.- The use the class method dataWithContentsOfURL from NSData to initialize a NSData object from the response url.
4.- NSData is really flexible, so you can do anything with it.
Note: dataWithContentsOfURL is synchronous, so if you want async, take a look at Grand Central Dispatch.
It doesn't seem clear to me what you are trying to do.
If you are trying to call a webservice with some parameters or just calling a website plus parameters in the end of it?
If webservice , just use the ASIHTTP Library located in here:
http://allseeing-i.com/ASIHTTPRequest/
If website, just append your parameter to the end of the string and call it.
Related
I'm new to Pentaho and using the Rest Client. I can get the Rest client to work by using generate rows for the url. But then I need to pass part of the result of the json to be part of the url for the next request. I'm not sure how to do this. Any suggestions.
Remember that PDI works with streams, you, for each REST request you made, you will have one row as result. You will have as many rows as many requests you do.
I'm not sure if you can deserialize the JSON object directly from the PDI interface, but in the worst scenario, you can use the "User Defined Java Class" to use some external library (like Gson) and deserialize the object.
Then, you can create another variable in the UDJC step and concatenate the attributes you need on the URL string that comes from the last step.
In the other hand you can use "Modified Javascript" to deserialize it and return the attributes you need to then concatenate it with the URL. To use it, just declare varibles inside the code, and then use "Get variables" button to retrieve the available fields to send to the next step.
There are many ways to do it, I suggest you to use the Modified Javascript because it's easier to handle.
You CAN parse the Json response, just use Json Input a a nex step, and then use XPath to parse the field you want: $.result.the.thing.u.want.
i'm trying to use cross domain jsonp. i have done this before using the callback function in the json file from the other domain. i'm looking at an example json data file that google uses in one of its tutorials:
http://earthquake.usgs.gov/earthquakes/feed/geojsonp/2.5/week -- here obviously the callback function here is eqfeed_callback. in the json file i'm trying to use, there is no callback function that kicks everything off, there is just a bracket [. the file starts off like:
[{"Address":"4441 Van Nuys Blvd","City":"Sherman Oaks" ...
and ends like:
}]
what should i do? is there another way to get at the data without a callback function? i can't edit this file. it's a service that i have a subscription to.
thx.
If it's not your server, and the server doesn't support JSONP, there's no way you can force it to return jsonp. You could try adding ?callback=callback to your url to see if that convinces the server to wrap it in a callback, but if it doesn't, you're out of luck.
Well, almost. There is actually a really dirty hack that you shouldn't use, which is to override javascript's standard Array constructor to assign the contents of the array to a global variable. But that's pretty hideous and I strongly advise against it.
Better ask the maintainer of the service if they're willing to support JSONP. Or better yet, add a CORS header.
I need to implement a custom event handler, which should for example handle URIs like:
- SomeAppName://SomeDomainClassName/ID to fetch a record from a database table
or
- SomeAppName://SomeControllerName/PushView/SomeAdditionalOptions to push a view controller and set additional options, for example this could be a calendar view which should be focused to show the calendar at a certain date.
I have been searching for existing REST frameworks, but so far I didn't figure how any exising framework could allow me to define formats for URIs and map them to local classes, actions, whatever it will be.
How could I 1) define and interpret REST like URIs and 2) map them to local actions or objects, without reinventing the wheel (e.g. inheriting from RESTKit)?
Or should I end up to write my own parser? In that case, pointers to good REST like URI lex/flex are welcome.
What I was looking for is called an URL router in Ruby worlds. There exist a few also for Objective C, more or less useful.
I ended up to write a custom URL Router, that is like ruby URL routers just split into basically two components (router and route). For the Router part (the mapper and URL dispatcher so to say) I looked at TTURLMap, which is part of Three20, but threw away 90% of code and changed the action handling to fit my needs. It has lot's of boilerpate code, but basically was what I needed for getting an idea for the router.
For the particular route handling I use SOCKit, which seems great and has well tested code.
Now I can for example have a local function hello which takes two params to show some values passed as URL:
Roter *router = [[Router alloc] init];
[router map:#"soc://:ident/:saySomething" toInstance:self with:#selector(hello:sayWhat:)];
[router dispatch:#"soc://3/hi"];
I'll add blocks as well, but for most cases selectors work well, because SOCKit passes them the actual values for basic parameter types (no need to use parse the dictionary with values from the URL).
Is there any way to get the actual data that will be sent when a NSURLConnection sends a NSURLRequest? Right now I'm mainly interested in looking at HTTP and HTTPS requests, but since NSURLRequest works for many protocols, it seems like there ought to be a general way to see the corresponding data for any type of request.
Am I missing something, or do I need to construct the request myself by combining the headers, body, etc?
Just to be clear, I'd like to do this programmatically, not by watching what shows up at the server end.
Update: At this point I've written code that effectively constructs a request using the data in a NSURLRequest, so I'm not asking how to go about that. However, I'd still like to know if there's a way to access the request stream that the URL loading system would generate. In other words, can I get access to the exact bytes that would be sent if a NSURLConnection were to send my NSURLRequest?
According your last question:
Check cookiesCenter.
Check credentialsStorage.
Log all headers for example on the first urlConnection's delegate method didReceiveResponse:.
Make this connection with local webservice and try to catch all headers, params, etc.
Also, the most simple way, is making request yourself.
Am I missing something, or do I need to construct the request myself
by combining the headers, body, etc?
It turns out that this is exactly what I needed to do, and it makes sense. It's the protocol handler (NSURLProtocol subclass), not NSURLRequest, that knows how to format the request for its particular protocol. Luckily, it's very easy to render an instance of NSURLRequest into a valid HTTP request. You can get the method (GET, POST, etc.), requested resource, and host from the request, and you can also get all the HTTP headers using the -allHTTPHeaderFields method, which returns a dictionary. You can then loop over the keys in the dictionary and add lines to the request like:
for (NSString *h in headers) {
[renderedRequest appendFormat:#"%#: %#\r\n", h, [headers objectForKey:h]];
}
Which NSURLConnection wrapper handles GET and POST equally well ?
For GET method, I prefer google's GTMHTTPFetcher over ASIHTTPRequest. ASIHTTPRequest uses delegate, which probably the idea you will come up with normally. But that's the exactly reason I chose not to use it because when you have several connections(many connections in my case), then each connection has its own delegate and you end up with too many object. Or you can have just 1 delegate but you have find a way to find out which response is for which connection.
GTMHTTPFetcher handle this way much better in my opinion. It uses 1 SEL for 1 connection, sorta like target-action model. The code is much cleaner than delegate model.
But for POST method, ASIHTTPRequest has ASIFormDataRequest. I did not find an easy way to do POST with GTMHTTPFetcher. It does have setPostData method to set post data. But you have to set post body and those mime parameters by yourselves(from what I have see) And that's the headache. I find it has another class called GTMHTTPUploadFetcher. But I can't really figure out how to use it (I keep getting the NSAssert "need upload location hdr").
So for POST, I guess ASIHTTPRequest is easier.
I did not get a chance to use facebook-ios-sdk. And would like to hear other opinion about it.
So is there NSURLConnection wrapper handle both GET and POST well ? And any idea how to use GTMHTTPUploadFetcher?
The GTMMIMEDocument class is used to create a stream for uploading via GTMHTTPFetcher (or via anything else that takes an NSInputStream.) An example is here.
GTMMIMEDocument keeps a sparse list of the data parts to be uploaded, avoiding duplicating the data in memory.