How to handle a string that comes from URL - ios

Im initializing a string from an URL as follow:
NSString* text = [NSString stringWithContentsOfURL:TheUrl encoding:NSASCIIStringEncoding error:&error];
The URL contains an s19 file, it seems like follow:
S111C019600FBDC09138BDC0353FBDFFCD16D0
S111C0272B024F3986FF393617BDFFB8323968
S110C035308F83000C8F35CCC350ED0AFD15
S111C0426000ED04ED02EC04ED00CCC08ABDFC
after this line I got the data into my text string. then I want to split the string to get an hex array, how can I do that? I was using the next line to get an array but It gives me the next (and it is right):
NSArray *arr = [text componentsSeparatedByString:#"\r\n"];
arr[0] --> S111C019600FBDC09138BDC0353FBDFFCD16D0
How can I split my text string into bytes/words values? something like this:
arr[0] --> C0
arr[1] --> 19
arr[2] --> 60

You can use a for loop and substringWithRange:, building up the range location as you iterate. The length of the range dictates how much you're taking from the original string on each iteration.
Something along the lines of:
NSRange range = NSMakeRange(0, 2);
while (range.location + range.length < sourceString.length) {
[array addObject:[sourceString substringWithRange:range];
range.location += range.length;
}

Related

How to grab values from unformatted string in ios objective-c?

I want to pick all the measurement values from below string and need to store into one array. I am getting this type of string from machine whoes name is "Kane". when I connected with this machine using bluetooth at that time I am getting this type of string. I am able to print this string into console. but I am not able to retrive values from this string and I want to store into an array. Can anyone please help me out. Thanks
i want to store values of [serial no,Log No,DATE,TIME,CO2,CO,CO2,CO2,CO,CO/CO2,T1,T2,DELTA] in one single array, like: [12345,0002,23/02/18,17:43:16, -0.00,0,0.00,-0.00,0,0.000,-N\F-,-N\F-,-N\F-].
here is the string which i actually get from machine and print into textview:
KANE458 SW19392 V1.13
SERIAL No. 12345
LOG No. 0002
DATE 23/02/18
TIME 17:43:16
------------------------
NEXT CAL 11/12/18
------------------------
COMMISSION TEST
------------------------
ANALYSER ZERO
-------------
CO2 % -0.00
CO ppm 0
FLUE INTEGRITY
--------------
CO2 % 0.00
MAX GAS FLOW
------------
CO2 % -0.00
CO ppm 0
CO/CO2 0.0000
MIN GAS FLOW
------------
CO2 % -0.00
CO ppm 0
CO/CO2 0.0000
FLOW & RETURN
-------------
T1 (null)C -N\F-
T2 (null)C -N\F-
DELTA (null)C -N\F-
I want an array containing everything after the last space character from every line
Edited Answer:
OK - so you want the "last word" of each line.
But ---- we assume you want to ignore lines that don't have a "value" at the end. So:
split the string into an array of "lines"
create a list of lines to ignore
loop through the array of lines
IF the line is in the ignore list, ignore it
else, get the last word and add it to our "last words" array
So...
NSString *searchedString = #"KANE458 SW19392 V1.13\n\nSERIAL No. 12345\n\nLOG No. 0002\n\nDATE 23/02/18 \nTIME 17:43:16\n\n------------------------\nNEXT CAL 11/12/18\n------------------------\n\nCOMMISSION TEST\n------------------------\n\nANALYSER ZERO\n-------------\nCO2 % -0.00\n\nCO ppm 0\n\nFLUE INTEGRITY\n--------------\n\nCO2 % 0.00\n\nMAX GAS FLOW\n------------\nCO2 % -0.00\nCO ppm 0\nCO/CO2 0.0000\n\nMIN GAS FLOW\n------------\nCO2 % -0.00\n\nCO ppm 0\n\nCO/CO2 0.0000\n\nFLOW & RETURN\n-------------\nT1 (null)C -N\F-\n\nT2 (null)C -N\F-\n\nDELTA (null)C -N\F-\n";
// lines to ignore, because they have no "values"
NSString *ignoreLines = #"COMMISSION TEST,ANALYSER ZERO,FLUE INTEGRITY,MAX GAS FLOW,MIN GAS FLOW,FLOW & RETURN";
// initialize an array for the last "word" from each line
NSMutableArray *arrayOfLastWords = [NSMutableArray array];
// split string into an array of "lines"
NSArray *arrayOfLines = [searchedString componentsSeparatedByString:#"\n"];
// for each "line"
for (NSString *s in arrayOfLines) {
// see if this line is listed as one of the lines to ignore
NSRange ignoreRange = [ignoreLines rangeOfString:s];
// if not found, then we want to get the last "word"
if (ignoreRange.location == NSNotFound) {
// find last space character
NSRange range = [s rangeOfString:#" " options:NSBackwardsSearch];
// if the line has a space
if (range.location != NSNotFound) {
// gett the last "word" - everything after the last space
NSString *result = [s substringFromIndex:range.location+1];
// append it to our array of last words
[arrayOfLastWords addObject:result];
}
}
}
NSLog(#"\n%#", arrayOfLastWords);
Gives a resulting array of:
(
"V1.13",
12345,
0002,
"",
"17:43:16",
"11/12/18",
"-0.00",
0,
"0.00",
"-0.00",
0,
"0.0000",
"-0.00",
0,
"0.0000",
"-NF-",
"-NF-",
"-NF-"
)
If you don't want the "V1.13" from the first line, just skip processing the first line.
If you don't know that the string will be returned with newLine separators, or if you don't know what strings will be returned that you need to ignore, then you need to write some additional code to split the string on various separators, and come up with criteria of what constitutes a "line with a value".
Original Answer:
You could do this with a "brute force" approach:
Split the string into an array of "lines"
loop through the lines
check the first "word" in each line
if it matches "CO2" or "T1", get the rest of the line (skipping spaces) and add it to an array
Or, you could use Regular Expressions. This is a partial approach:
NSString *searchedString = #"KANE458 SW19392 V1.13\n\nSERIAL No. 12345\n\nLOG No. 0002\n\nDATE 23/02/18 \nTIME 17:43:16\n\n------------------------\nNEXT CAL 11/12/18\n------------------------\n\nCOMMISSION TEST\n------------------------\n\nANALYSER ZERO\n-------------\nCO2 % -0.00\n\nCO ppm 0\n\nFLUE INTEGRITY\n--------------\n\nCO2 % 0.00\n\nMAX GAS FLOW\n------------\nCO2 % -0.00\nCO ppm 0\nCO/CO2 0.0000\n\nMIN GAS FLOW\n------------\nCO2 % -0.00\n\nCO ppm 0\n\nCO/CO2 0.0000\n\nFLOW & RETURN\n-------------\nT1 (null)C -N\F-\n\nT2 (null)C -N\F-\n\nDELTA (null)C -N\F-\n";
NSError *error = nil;
NSRange searchedRange = NSMakeRange(0, [searchedString length]);
// search for "CO2" at the start of a line, and capture everything to the end of the line
NSString *pattern = #"\\nCO2\\s*([^\\n\\r]*)";
NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern: pattern options:0 error:&error];
NSArray* matches = [regex matchesInString:searchedString options:0 range: searchedRange];
// for each found match, skip spaces and save the rest of the line
for (NSTextCheckingResult* match in matches) {
NSString* matchText = [searchedString substringWithRange:[match range]];
NSRange group1 = [match rangeAtIndex:1];
[arrayOfCO2 addObject:[searchedString substringWithRange:group1]];
}
// search for "T1" at the start of a line, and capture everything to the end of the line
pattern = #"\\nT1\\s*([^\\n\\r]*)";
regex = [NSRegularExpression regularExpressionWithPattern: pattern options:0 error:&error];
matches = [regex matchesInString:searchedString options:0 range: searchedRange];
// for each found match, skip spaces and save the rest of the line
for (NSTextCheckingResult* match in matches) {
NSString* matchText = [searchedString substringWithRange:[match range]];
NSRange group1 = [match rangeAtIndex:1];
[arrayOfT1 addObject:[searchedString substringWithRange:group1]];
}
NSLog(#"");
NSLog(#"CO2:");
NSLog(#"%#", arrayOfCO2);
NSLog(#"");
NSLog(#"T1:");
NSLog(#"%#", arrayOfT1);
This is the result from the sample string you posted:
CO2:
(
"% -0.00",
"% 0.00",
"% -0.00",
"% -0.00"
)
T1:
(
"(null)C -NF-"
)
It seems that the string has new lines (Assuming this is a static text). This would retrieve the values:
Swift :
let stringVal = "CO2 % -23.0\n\nO2 % -0.00\n\nT1 ppm -N/_F"
let arrayNewLine = stringVal.components(separatedBy: "\n")
let strCO2 = arrayNewLine[0].components(separatedBy: " ")[0]
let strO2 = arrayNewLine[1].components(separatedBy: " ")[0]
let strT1 = arrayNewLine[2].components(separatedBy: " ")[0]
Objective C :
NSString *stringVal = #"CO2 % -23.0\n\nO2 % -0.00\n\nT1 ppm -N/_F";
NSArray *arrNewLine = [stringVal componentsSeparatedByString:#"\n"];
NSString *strCO2 = [[[arrNewLine objectAtIndex:0] componentsSeparatedByString:#" "] objectAtIndex:0];
NSString *strO2 = [[[arrNewLine objectAtIndex:1] componentsSeparatedByString:#" "] objectAtIndex:0];
NSString *strT1 = [[[arrNewLine objectAtIndex:2] componentsSeparatedByString:#" "] objectAtIndex:0];

NSScanner to scan until a character or number is Hit

My problem is that I want to extract the data from the string. The strings prints 1000 lines with some random data fetched from web. The string is like this:
Level
1
2
3
4
5
6
7
8
Score
0
0
0
0
0
0
0
0
I need NSScanner to save data in array like this
int *extractedLevelData = {1, 2, 3, 4, 5, 6, 7, 8}
int *extractedScoreData = {0, 0, 0, 0, 0, 0, 0, 0}
The problem is that the row of number in level and score is dynamic, it goes from 1 then new line then 2 then new line then 3 then new line and so on. The challenge is that sometimes it can be 1 to 5 or sometimes it can be 1 only and sometimes maximum is 1 to 8. They show up in the same style as shown above followed by new line character. Same with the "Score".
I've tried this but the saved data returns null in NSLog, it has been 7 days since I'm learning Objective C and I'm almost finished with the app until this problem came.
Here is what I've tried:
NSString *extractedData;
NSCharacterSet *tripleNewLine = [NSCharacterSet characterSetWithCharactersInString:#"\n\n\n"];
[firstScanner scanString:#"Level" intoString:NULL];
[firstScanner setScanLocation:[firstScanner scanLocation]];
[firstScanner scanUpToCharactersFromSet:tripleNewLine intoString:&extractedData];
NSLog(#"%#", extractedData);
Note that this is just a code snippet and the real problem is really complex but if someone smart enough to solve this problem then my problem will be solved! The logic can be: tell the NSScanner to scan from "Level" text with numbers until it hit any character.
So if you don't really want to use NSScanner another solution can be the following:
Split the whole string by Score this will give you two strings one with the values from score and one with the values from level:
`NSArray *components = [serverString componentsSeparatedByString:#"Score"];`
The above line will split your server string in two strings contained by components array. One will have all the values from Level including Level, and the other one will have the values from Score without Score value.
Now you can split those two strings by \n character, this will result in two arrays with all the values from a row.
if(components.count > 1) { //we better check if we have both substrings
NSArray *levels = [[components objectAtIndex:0] componentsSeparatedByString:#"\n"];
NSArray *scores = [[components objectAtIndex:1] componentsSeparatedByString:#"\n"];
}
Now after you have the all the values we should create a method that will check if a value is an actual number, if not we will remove it from the array.
-(NSArray *)checkAndRemoveNonNumbersFromArray:(NSArray *)checkedArray {
NSCharacterSet *alphaNums = [NSCharacterSet decimalDigitCharacterSet];
checkedArray = [checkedArray filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(NSString *evaluatedObject, NSDictionary *bindings) {
NSCharacterSet *inStringSet = [NSCharacterSet characterSetWithCharactersInString:evaluatedObject];
return [alphaNums isSupersetOfSet:inStringSet];
}]];
return checkedArray;
}
Now that we have the method created, the code from point 2 will become:
if(components.count > 1) { //we better check if we have both substrings
NSArray *levels = [[components objectAtIndex:0] componentsSeparatedByString:#"\n"];
NSArray *scores = [[components objectAtIndex:1] componentsSeparatedByString:#"\n"];
levels = [self checkAndRemoveNonNumbersFromArray:levels];
scores = [self checkAndRemoveNonNumbersFromArray:scores];
}
Now levels & scores will have only numerical values from those two arrays. Note, this is not the best solution, is more a solution to show you how you can play with strings, after you understand this implementation I think you can find one that uses NSScaner.
I see that you are passing #"Level" as a string input rather than a variable, which is not correct. I assume Level is the NSString object in this case. You can use this solution. This will print all the data from Level
NSScanner *scanner = [NSScanner scannerWithString:Level];
while([scanner isAtEnd] == NO) {
[scanner setScanLocation:[scanner scanLocation]];
[scanner scanUpToCharactersFromSet:tripleNewLine intoString:&extractedData];
NSLog(#"%#", extractedData);
}

Count characters before some string iOS

I need to count characters in string before some string and after some string. For example, I have string "This is example string" and I need to know howmany characters are before word "example" (it is 8 chars in this case) and how many characters are after word "example" (7 in that case...). My idea was to loop that string and count every character, but how to stop it before that requied word? Thanks for every idea!
check this out
NSString *sample = #"This is example string";
NSRange b = [sample rangeOfString:#"example"];
if (b.location != NSNotFound) {
NSLog(#"%d characters before", b.location);
NSLog(#"%d characters after", [sample length] - b.location - b.length);
}

getting certain portion of nsstring

I have string as follows in objective c
NSString *str = #"access_token=E2JmCPLtVySGn-cGGJGGnQ&email=abc#gmail.com";
How can i get only E2JmCPLtVySGn-cGGJGGnQ ?
You can use a Regular Expression (RegEx) to find character patterns.
The pattern matching syntax can be found in the ICU User Guide Regular Expressions
In the example the pattern is: find the first "=" and all characters up to but not including the character "&". In the pattern '(?<=access_token=)" is a look-behind assertion meaning that the "access_token=" must precede the matched text, "[^&]+" the brackets the "[]" mean a character class, the "^" al but the following character, the "+" means one or more.
NSString *str = #"access_token=E2JmCPLtVySGn-cGGJGGnQ&email=abc#gmail.com";
NSString *regexPattern = #"(?<=access_token=)[^&]+";
NSString *found = nil;
NSRange range = [str rangeOfString:regexPattern options:NSRegularExpressionSearch];
if (range.location != NSNotFound) {
found = [str substringWithRange:range];
}
NSLog(#"Range: %#", NSStringFromRange(range));
NSLog(#"found: %#", found);
NSLog output if found:
Range: {13, 22}
found: E2JmCPLtVySGn-cGGJGGnQ
There is a method of the NSString class called rangeOfString: that returns an NSRange struct. If you know that your returned value always has the text access_token= and also includes &email and the format is always the same, you can use this rangeOfString: method to sniff out the token.
NSRange accessTokenRange = [str rangeOfString:#"access_token="];
//this would return (0,13) for index:0, length: 13
NSRange emailRange = [str rangeOfString:#"&email="];
//this would return (34,7)
NSInteger tokenLength = ( emailRange.location + 1 ) - accessTokenRange.length;
//the point where &email begins is at index 34, but it starts at 0
//so it's actually the 35th character
//the access_token= string is 13 characters long, so 35-13 = 22
//so you know that the actual token value is 22 characters long
NSRange trueTokenRange = NSMakeRange(accessTokenRange.length,tokenLength);
NSString *tokenSubstring = [str substringWithRange:trueTokenRange];
I don't think my math is off, zero indexing can introduce off by 1 errors if you're not careful, I usually have NSLog going on each range so I can double check where I need to add or subtract 1. But essentially you'll be starting at the 14th character, which is index 13 of the string, and reading the next 22 characters.

Check Objective-C String for specific characters

For an app I'm working on, I need to check if a text field contains only the letters A, T, C, or G. Furthermore, I would like to make specialized error messages for any other inputed characters. ex) "Don't put in spaces." or "The letter b isn't an accepted value." I have read a couple other posts like this, but they are alphanumeric, I only want specified characters.
One approach for you, far from unique:
NString has methods to find substrings, represented as an NSRange of location & offset, made up from characters in a given NSCharacterSet.
The set of what should be in the string:
NSCharacterSet *ATCG = [NSCharacterSet characterSetWithCharactersInString:#"ATCG"];
And the set of what shouldn't:
NSCharacterSet *invalidChars = [ATCG invertedSet];
You can now search for any range of characters consisting of invalidChars:
NSString *target; // the string you wish to check
NSRange searchRange = NSMakeRange(0, target.length); // search the whole string
NSRange foundRange = [target rangeOfCharacterFromSet:invalidChars
options:0 // look in docs for other possible values
range:searchRange];
If there are no invalid characters then foundRange.location will be equal to NSNotFound, otherwise you change examine the range of characters in foundRange and produce your specialised error messages.
You repeat the process, updating searchRange based on foundRange, to find all the runs of invalid characters.
You could accumulate the found invalid characters into a set (maybe NSMutableSet) and produce the error messages at the end.
You can also use regular expressions, see NSRegularExpressions.
Etc. HTH
Addendum
There is a really simple way to address this, but I did not give it as the letters you give suggest to me you may be dealing with very long strings and using provided methods as above may be a worthwhile win. However on second thoughts after your comment maybe I should include it:
NSString *target; // the string you wish to check
NSUInteger length = target.length; // number of characters
BOOL foundInvalidCharacter = NO; // set in the loop if there is an invalid char
for(NSUInteger ix = 0; ix < length; ix++)
{
unichar nextChar = [target characterAtIndex:ix]; // get the next character
switch (nextChar)
{
case 'A':
case 'C':
case 'G':
case 'T':
// character is valid - skip
break;
default:
// character is invalid
// produce error message, the character 'nextChar' at index 'ix' is invalid
// record you've found an error
foundInvalidCharacter = YES;
}
}
// test foundInvalidCharacter and proceed based on it
HTH
Use NSRegulareExpression like this.
NSString *str = #"your input string";
NSRegularExpression *regEx = [NSRegularExpression regularExpressionWithPattern:#"A|T|C|G" options:0 error:nil];
NSArray *matches = [regEx matchesInString:str options:0 range:NSMakeRange(0, str.length)];
for (NSTextCheckingResult *result in matches) {
NSLog(#"%#", [str substringWithRange:result.range]);
}
Also for the options parameter you have to look in the documentation to pick one that fits.
Look at the NSRegularExpression class reference.
Visit: https://developer.apple.com/library/mac/documentation/Foundation/Reference/NSRegularExpression_Class/Reference/Reference.html

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