I define a path variable in Xcode source tree called "MY_SRC_DIR". I would like to get the value of this environment variable and put it in a NSString in the obj-c code. For example,
-(NSString*) getSourceDir
{
return #"${MY_SRC_DIR}"; // not the right solution and this is the question
}
From http://rosettacode.org/wiki/Environment_variables#Objective-C:
[[NSProcessInfo processInfo] environment] returns an NSDictionary of the current environment.
For example:
[[[NSProcessInfo processInfo] environment] objectForKey:#"MY_SRC_DIR"]
Just expose the desired var into the Environment Variables list of your current Xcode's deployment Scheme and you'll be able to retrieve it at runtime like this:
NSString *buildConfiguration = [[NSProcessInfo processInfo] environment][#"BUILD_CONFIGURATION"];
It also applies to swift based projects.
Hope it helps!! :]
Here is another way to do it:
.xcconfig file:
FIRST_PRESIDENT = '#"Washington, George"'
GCC_PREPROCESSOR_DEFINITIONS = MACRO_FIRST_PRESIDENT=$(FIRST_PRESIDENT)
objective C code:
#ifdef FIRST_PRESIDENT
NSLog(#"FIRST_PRESIDENT is defined");
#else
NSLog(#"FIRST_PRESIDENT is NOT defined");
#endif
#ifdef MACRO_FIRST_PRESIDENT
NSLog(#"MACRO_FIRST_PRESIDENT is %#", MACRO_FIRST_PRESIDENT);
#else
NSLog(#"MACRO_FIRST_PRESIDENT is undefined, sorry!");
#endif
Console output -- I've stripped out the garbage from NSLog:
FIRST_PRESIDENT is NOT defined
MACRO_FIRST_PRESIDENT is Washington, George
The only way I've found to get a build time environment variable as a string is to put it in an dictionary element like this:
<key>Product Name</key>
<string>$PRODUCT_NAME</string>
and then retrieve it like this:
NSDictionary* infoDict = [[NSBundle mainBundle] infoDictionary];
NSString* productName = infoDict[#"Product Name"];
NSLog(#"Product Name: %#", productName);
The best answer to this question is the accepted answer on this question.
Constants in Objective-C
You'll get the most mileage, and won't need any special methods to get the value you're searching for as long as you import the file into whatever .h/.m file is going to consume said value.
Related
I am doing an NSLog of an array but instead of data it shows the following values. I do not know how to fix this issue and get the values from the array
if(!surveyQuestions){
surveyQuestions=[[NSMutableArray alloc]init];
}
Total Survey Questions 3
2012-07-31 08:54:53.555 SQL[442:9203] SurveyQuestions (
"<QuestionData: 0x4da10f0>",
"<QuestionData: 0x4b9f120>",
"<QuestionData: 0x4ba42e0>"
)
I'm not sure what you're trying to do but: it's certain that the poor array object has no idea what and how your own custom class does, its best possibility to print an instance of your class is to call its description method, which you see, and which is not really helpful. You maybe want to do two things:
I. If you only want to print your objects like this, override the description method of your class and use some format string (given that you haven't written a single line of code I have to fall back to guess):
- (NSString *)description
{
return [NSString stringWithFormat:#"Name: %#, address: %#", self.name, self.address];
}
II. If you want to use the data of your class elsewhere, you probably want to loop through its properties manually:
for (QuestionData *d in surveyQuestions)
{
NSLog(#"%#", d.name);
// etc.
}
You need to do something like this:
NSArray *theArray = [[NSArray alloc] initWith...];
NSLog(#"array contents: %#", theArray);
I want to check whether a string contains any of the substrings that I place in an array. Basically, I want to search the extensions of a file, and if the file is an "image", i want certain code to execute. The only way I can think of categorizing the file as an "Image" without downloading the file is through the substring in a string method. This is my code so far:
NSString *last5Chars = [folderName substringFromIndex: [folderName length] - 5];
NSRange textRangepdf;
textRangepdf =[last5Chars rangeOfString:#"pdf"];
if(textRangepdf.location != NSNotFound)
{
[self.itemType addObject:#"PDF.png"];
}
Is it possible to do this where I can check if last5Chars contains #"jpg" or #"gif" of #"png" etc...?? Thanks for helping!
NSString *fileName;
NSArray *imgExtArray; // put your file extensions in here
BOOL isImage = [imgExtArray containsObject:[fileName pathExtension]];
[folderName hasSuffix:#".jpg"] || [folderName hasSuffix:#".gif"]
obviously you can put it into a loop, if you have a whole arrayful.
Rather than mess about with ranges and suffixes, NSString has a method that treats an NSString as a path and returns an extension, it's called pathExtension.
Have a look in the NSString Documentation
Once you get the extension you can check it against whatever strings you want.
I get from an URL this result :
NSString *result = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
it looks like this :
[{"modele":"Audi TT Coup\u00e9 2.0 TFSI","modele_annee":null,"annee":"2007","cilindre":"4 cyl","boite":"BVM","transmision":"Traction","carburant":"ES"},
{"modele":"Audi TT Coup\u00e9 2.0 TFSI","modele_annee":null,"annee":"2007","cilindre":"4 cyl","boite":"BVM","transmision":"Traction","carburant":"ES"}]
So it contains 2 dictionaries. I need to take the objects from all the keys from this result. How can I do this?
I tried this : NSDictionary vehiculesPossedeDictionary=(NSDictionary *)result;
and then this : [vehiculesPossedeDictinary objectForKey:#"modele"]; but this is not working.
Please help me... Thanks in advance
What you have is a JSON string which describes an "array" containing two "objects". This needs to be converted to Objective-C objects using a JSON parser, and when converted will be an NSArray containing two NSDictionarys.
You aren't going to be able to get your dictionary directly from a string of JSON. You are going to have to going to have to run it through a JSON parser first.
At this point, there is not one build into the iOS SDK, so you will have to download a third-party tool and include it in your project.
There are a number of different JSON parser, include TouchJSON, YAJL, etc. that you can find and compare. Personally, I am using JSONKit.
#MatthewGillingham suggests JSONKit. I imagine it does fine, but I've always used its competitor json-framework. No real reason, I just found it first and learned it first. I do think its interface is somewhat simpler, but plenty of people do fine with JSONKit too.
Using json-framework:
require JSON.h
...and then
NSString *myJsonString = #"[{'whatever': 'this contains'}, {'whatever', 'more content'}]";
NSArray *data = [myJsonString JSONValue];
foreach (NSDictionary *item in data) {
NSString *val = [item objectForKey:#"whatever"];
//val will contain "this contains" on the first time through
//this loop, then "more content" the second time.
}
If you have array of dictionary just assign objects in array to dictionary like
NSDictionary *dictionary = [array objectAtIndes:0];
and then use this dictionary to get values.
I would like to define the following function in Objective-C. I have provided pseudo-code to help illustrate what I'm trying to do.
PSEUDOCODE:
function Foo(param) {
string temp;
if(param == 1) then
temp = "x";
else if(param == 2) then
temp = "y";
else if(param == 3) then
temp = "z";
else
temp = "default";
end if
return temp;
}
For some reason if I do this... the variable who I assign it to results in a "BAD Access" error.
I don't know what the difference between:
static NSstring *xx;
or the non-static:
NSString *xx;
declarations are, and how or why I would want to use one over the other.
I also do not fully understand the initializers of NSString, and how they differ. For example:
[[NSString alloc] initWithString:#"etc etc" ];
or the simple assignment:
var = #""
or even:
var = [NSString stringWithString:#"etc etc"];
Can you give me a hand please?
So far, using the NSString value returned from functions like those listed above, always causes an error.
static NSstring *xx;
That declares a statically allocated variable, much like it does in C.
NSstring *xx;
Inside a method that declares a normal local stack variable, just as it does in C.
As you should be aware, the difference between the two is that the first will keep its value between invocations of the function (and can cause trouble if the function is called from multiple threads).
[[NSString alloc] initWithString:#"etc etc"]
That creates a new NSString object, with the contents etc etc. This may or may not be the same as any other NSString object in your program with the same contents, but you don't have to care. Memory management wise, you own it, so you are responsible for ensuring that you eventually call release or autorelease on it to avoid leaking memory.
#"etc etc"
[NSString stringWithString:#"etc etc"]
Those are basically the same. Both give you an NSString object with the contents etc etc. This may or may not be the same as any other NSString object in your program with the same contents, but you don't have to care. Memory management wise, you do not own it, so you must not call release or autorelease on the object unless you first took ownership by calling retain. Also, since you do not own it, you can use it within your method, pass it as a parameter to other methods, and even use it as the return value from your method, but you may not store it in an ivar or static variable without taking ownership by calling retain or making a copy (with copy).
Also, note that "" and #"" are very different. The first gives you a const char * exactly as it does in C, while the second gives you an NSString object. Your program will crash if you use a const char * where the code expects an NSString object.
You can do it this way:
- (NSString *)functionName:(int)param {
NSString *result = nil;
switch (param) {
case 1:
result = [NSString stringWithString:#"x"];
break;
case 2:
result = [NSString stringWithString:#"y"];
break;
case 3:
result = [NSString stringWithString:#"z"];
break;
default:
result = [NSString stringWithString:#"defaultv"];
break;
}
return result;
}
Post real code, not pseudo code, as it makes it much easier to answer your question in concrete terms.
Given that you indicate that you are quite new to Objective-C, I would suggest starting with the language guide and then moving on to the memory management guide.
I want my app to do something when the last NSLog has a certain string. I thought I could realize this with an if-query and isEqualtoString, but how can I make this?
Sorry for my bad English ;)
Maybe I don't understand what you're trying to do, but you can just create the string somewhere, log it, and then test it:
NSInteger _someInt = 2;
NSString *_someString = #"bananas";
NSString *_stringToBeLogged = [NSString stringWithFormat:#"%d %#", _someInt, _someString];
NSLog(#"%#", _stringToBeLogged);
if ([_stringToBeLogged isEqualToString:#"2 bananas"]) {
NSLog(#"I logged two bananas...");
}
You could consider creating your own custom log function which calls NSLog() after checking for your string constant. This would keep your code a bit cleaner if you want this functionality in multiple places and also allows you to easily extend the logging function further if desired.