I am using GDataXML in my iOS application and want a simple way to format and print an XML string - "pretty print"
Does anyone know of an algorithm in Objective C, or one that works in another language I can translate?
You can modify the source code of GDataXMLNode direcly:
- (NSString *)XMLString {
...
// enable formatting (pretty print / beautifier)
int format = 1; // changed from 0 to 1
...
}
Alternative:
As I didn't want to modify the library directly (for maintenance reasons), I wrote that category to extend the class from outside:
GDataXMLNode+PrettyFormatter.h:
#import "GDataXMLNode.h"
#interface GDataXMLNode (PrettyFormatter)
- (NSString *)XMLStringFormatted;
#end
GDataXMLNode+PrettyFormatter.m:
#import "GDataXMLNode+PrettyFormatter.h"
#implementation GDataXMLNode (PrettyFormatter)
- (NSString *)XMLStringFormatted {
NSString *str = nil;
if (xmlNode_ != NULL) {
xmlBufferPtr buff = xmlBufferCreate();
if (buff) {
xmlDocPtr doc = NULL;
int level = 0;
// enable formatting (pretty print / beautifier)
int format = 1;
int result = xmlNodeDump(buff, doc, xmlNode_, level, format);
if (result > -1) {
str = [[[NSString alloc] initWithBytes:(xmlBufferContent(buff))
length:(xmlBufferLength(buff))
encoding:NSUTF8StringEncoding] autorelease];
}
xmlBufferFree(buff);
}
}
// remove leading and trailing whitespace
NSCharacterSet *ws = [NSCharacterSet whitespaceAndNewlineCharacterSet];
NSString *trimmed = [str stringByTrimmingCharactersInSet:ws];
return trimmed;
}
#end
I've used HTML Tidy (http://tidy.sourceforge.net/) for things like this. It's a C library so can be linked in to and called from an Objective C runtime fairly easily as long as you're comfortable with C. The C++ API is callable from Objective C++ so that might be easier to use if you're comfortable with Objective C++.
I've not used the C or C++ bindings; I did it via Ruby or Python but it's all the same lib. It will read straight XML (as well as potentially dirty HTML) and it has both simple and pretty print options.
Related
I know how to add custom functions to NSNumber for NSExpression to work with it. But for use it i need to declarate a string like "FUNCTION(1, 'sin')". Is is any way to declarate it just like "sin(1)"?
No, you cannot extend the syntax understood by NSExpression(format:).
For advanced expression parsing and evaluating, use 3rd party solutions
such as DDMathParser.
The selected answer is, in my opinion, ridiculous. You can, of course, simply reformat your string to your desired custom function, no need to become dependent on an entire library.
In your case, something like the following would work just fine.
NSString *equation = #"2+sin(54.23+(2+sin(sin(3+5))))-4+(5-3)+cos(4)";//your equation here
NSArray *functionNames = #[#"sin", #"cos", #"tan"];//your supported functions here
for (NSString *functionName in functionNames) {
NSString *functionPrefix = [NSString stringWithFormat:#"%#(", functionName];
while ([equation containsString:functionPrefix]) {
int parensLevel = 1;
int functionParameterIndex = ((int)[equation rangeOfString:functionPrefix].location)+((int)functionPrefix.length);
int characterIndex = functionParameterIndex;
while (characterIndex < equation.length) {
NSString *character = [equation substringWithRange:NSMakeRange(characterIndex, 1)];
if ([character isEqualToString:#"("]) {
parensLevel++;
} else if ([character isEqualToString:#")"]) {
parensLevel--;
}
if (parensLevel == 0) {
break;
}
characterIndex++;
}
if (parensLevel != 0) {
break;//parens weren't balanced, error handle as needed
}
NSString *functionParameter = [equation substringWithRange:NSMakeRange(functionParameterIndex, characterIndex-functionParameterIndex)];
NSString *function = [NSString stringWithFormat:#"%#(%#)", functionName, functionParameter];
equation = [equation stringByReplacingOccurrencesOfString:function withString:[NSString stringWithFormat:#"FUNCTION(%#,'%#')", functionParameter, functionName]];
}
}
//po string = "2+FUNCTION(54.23+(2+FUNCTION(FUNCTION(3+5,'sin'),'sin')),'sin')-4+(5-3)+FUNCTION(4,'cos')"
I wrote this in Objective-C but it works converted to swift as well.
I’ve developed an iOS app in which we can send emojis from iOS to web portal and vice versa. All emojis sent from iOS to web portal are displaying perfect except “© and ®”.
Here is the emoji encoding piece of code.
NSData *data = [messageBody dataUsingEncoding:NSNonLossyASCIIStringEncoding];
NSString *encodedString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
// This piece of code returns \251\256 as Unicodes of copyright and registered emojis, as these two Unicodes are not according to standard code so it doesn't display on web portal.
So what should I do to convert them standard Unicodes?
Test Run :
messageBody = #"Copy right symbol : © AND Registered Mark symbol : ®";
// Encoded string i get from the above encoding is
Copy right symbol : \\251 AND Registered Mark symbol : \\256
Where as it should like this (On standard unicodes )
Copy right symbol : \\u00A9 AND Registered Mark symbol : \\u00AE
First, I will try to provide the solution. Then I will try to explain why.
Escaping non-ASCII chars
To escape unicode chars in a string, you shouldn't rely on NSNonLossyASCIIStringEncoding. Below is the code that I use to escape unicode&non-ASCII chars in a string:
// NSMutableString category
- (void)appendChar:(unichar)charToAppend {
[self appendFormat:#"%C", charToAppend];
}
// NSString category
- (NSString *)UEscapedString {
char const hexChar[] = "0123456789ABCDEF";
NSMutableString *outputString = [NSMutableString string];
for (NSInteger i = 0; i < self.length; i++) {
unichar character = [self characterAtIndex:i];
if ((character >> 7) > 0) {
[outputString appendString:#"\\u"];
[outputString appendChar:(hexChar[(character >> 12) & 0xF])]; // append the hex character for the left-most 4-bits
[outputString appendChar:(hexChar[(character >> 8) & 0xF])]; // hex for the second group of 4-bits from the left
[outputString appendChar:(hexChar[(character >> 4) & 0xF])]; // hex for the third group
[outputString appendChar:(hexChar[character & 0xF])]; // hex for the last group, e.g., the right most 4-bits
} else {
[outputString appendChar:character];
}
}
return [outputString copy];
}
(NOTE: I guess Jon Rose's method does the same but I didn't wanna share a method that I didn't test)
Now you have the following string: Copy right symbol : \u00A9 AND Registered Mark symbol : \u00AE
Escaping unicode is done. Now let's convert it back to display the emojis.
Converting back
This is gonna be confusing at first but this is what it is:
NSData *data = [escapedString dataUsingEncoding:NSUTF8StringEncoding];
NSString *converted = [[NSString alloc] data encoding:NSNonLossyASCIIStringEncoding];
Now you have your emojis (and other non-ASCIIs) back.
What is happening?
The problem
In your case, you are trying to create a common language between your server side and your app. However, NSNonLossyASCIIStringEncoding is pretty bad choice for the purpose. Because this is a black-box that is created by Apple and we don't really know what it is exactly doing inside. As we can see, it converts unicode into \uXXXX while converting non-ASCII chars into \XXX. That is why you shouldn't rely on it to build a multi-platform system. There is no equivalent of it in backend platforms and Android.
Yet it is pretty mysterious, NSNonLossyASCIIStringEncoding can still convert back ® from \u00AE while it is converting it into \256 in the first place. I'm sure there are tools on other platforms to convert \uXXXX into unicode chars, that shouldn't be a problem for you.
messageBody is a string there is no reason to convert it to data only to convert it back to a string. Replace your code with
NSString *encodedString = messageBody;
If the messageBody object is incorrect then the way to fix it is to change the way it was created. The server sends data, not strings. The data that the server sends is encoding in some agreed upon way. Generally this encoding is UTF-8. If you know the encoding you can convert the data to a string; if you don't, then the data is gibberish that cannot be read. If the messageBody is incorrect, the problem occurred when it was converted from the data that the server sent. It seems likely that you are parsing it with the incorrect encoding.
The code you posted is just plain wrong. It converts a string to data using one encoding (ASCII) and the reads that data with a different encoding (UTF8). That is like translating a book to Spanish and then having a Portuguese speaker translate it back - it might work for some words, but it is still wrong.
If you are still having trouble then you should share the code of where messageBody is created.
If you server expects a ASCII string with all unicode characters changed to \u00xx then you should first yell at your server guy because he is an idiot. But if that doesn't work you can do the following code
NSString* messageBody = #"Copy right symbol : © AND Registered Mark symbol : ®";
NSData* utf32Data = [messageBody dataUsingEncoding:NSUTF32StringEncoding];
uint32_t *bytes = (uint32_t *) [utf32Data bytes];
NSMutableString* escapedString = [[NSMutableString alloc] init];
//Start a 1 because first bytes are for endianness
for(NSUInteger index = 1; index < escapedString.length / 4 ;index++ ){
uint32_t charValue = bytes[index];
if (charValue <= 127) {
[escapedString appendFormat:#"%C", (unichar)charValue];
}else{
[escapedString appendFormat:#"\\\\u%04X", charValue];
}
}
I'm really do not understand your problem.
You can simply convert ANY character into nsdata and return it into string.
You can simply pass UTF-8 string including both emoji and other symbols using POST request.
NSString* newStr = [[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding];
NSData* data = [newStr dataUsingEncoding:NSUTF8StringEncoding];
It have to work for both server and client side.
But, of course, you have got the other problem that some fonts do not support allutf-8 chars. That's why, e.g., in terminal you might not see some of them. But this is beyong the scope of this question.
NSNonLossyASCIIStringEncoding is used only then you really wnat to convert symbol into chain of symbols. But it is not needed.
I'm working with AllJoyn on iOS using objective C. I'm having trouble parsing an ALLJOYN_ARRAY type in objective C. The problem is that the MsgArg type (C++) is abstracted through the AJNMessagArgument type (objective c). The sample code for parsing an array signature of "a{iv}" in c++ is as follows:
MsgArg *entries;
size_t num;
arg.Get("a{iv}", &num, &entries);
for (size_t i = 0; i > num; ++i) {
char *str1;
char *str2;
uint32_t key;
status = entries[i].Get("{is}", &key, &str1);
if (status == ER_BUS_SIGNATURE_MISMATCH) {
status = entries[i].Get("{i(ss)}", &key, &str1, &str2);
}
}
Now in objective c, the msgarg is the handle of the AJNMessageArgument type. I've tried the following to try getting this to work with no avail:
AJNMessageArgument *strings = [AJNMessageArgument new];
size_t numVals;
QStatus status = [supportedLangsArg value: #"as", &numVals, strings.handle];
if(status != ER_OK){
NSLog(#"ERROR: Could not supported languages from the message argument");
}
This returns ER_OK, but I can't see any data in the handle via the debugger like I can with valid AJNMessageArguments.
Passing in &strings.handle throws a compile error "Address of property expression required".
I've tried quite a few other things, but none make much sense compared to the one above.
Please help me! I need an example of how to parse an "as" signature in objc. I haven't been able to find any docs for this.
Thanks for any help!
Ok, short story is this can't be done without adding custom code to the AJNMessageArgument Class. This is because in this scenario, the "value" method will return a pointer to an array of MsgArg types. Objective C cannot interact with MsgArg - Which is the whole reason they created the AJNMessageArgument wrapper for Objective C.
Here is how it is done:
Add this static method to your AJNMessageArgument.mm class:
+ (NSArray*)getAJNMessageArgumentArrayFromMsgArgArray:(void*)arg : (int)size
{
NSMutableArray * toReturn = [NSMutableArray new];
MsgArg *msgArray = (MsgArg*) arg;
for (int i = 0; i < size; ++i)
{
void * msarg = malloc(sizeof(MsgArg));
MsgArg arg = msgArray[i];
memcpy(msarg, &msgArray[i], sizeof(MsgArg));
AJNMessageArgument *toAdd = [[AJNMessageArgument alloc] initWithHandle:msarg];
[toReturn addObject:toAdd];
}
return [toReturn copy];
}
Don't forget to add the method definition to the AJNMessageArgument.h file:
+ (NSMutableArray*)getAJNMessageArgumentArrayFromMsgArgArray:(void*)arg : (int)size
So now, in our objective C code, we can parse the AJNMessageArgument with signature "as" - but we can't cast it to the MsgArg type yet because we can't access that structure outside of objc++ - so we will use a (void *).
+ (NSArray*)getSupportedLangsFromMessageArgument:(AJNMessageArgument*)supportedLangsArg
{
void *strings; //void * to keep track of MsgArg array data.
size_t numVals;
QStatus status = [supportedLangsArg value: #"as", &numVals, &strings];
if(status != ER_OK){
NSLog(#"ERROR: Could not supported languages from the message argument");
}
NSMutableArray *arrayOfMsgArgs = [AJNMessageArgument getAJNMessageArgumentArrayFromMsgArgArray:strings :numVals];
//Now loop through the resulting AJNMessageArguments of type ALLJOYN_STRING - and parse out the string.
NSMutableArray *arrayOfStrings = [NSMutableArray new];
for (AJNMessageArgument *arg in arrayOfMsgArgs) {
NSString* msgArgValue = [AboutUtil getStringFromMessageArgument:arg];
[arrayOfStrings addObject:msgArgValue];
}
return [arrayOfStrings copy];
}
Now we have an NSArray of NSStrings. Whew.
In case you were wanting to see the code to get the NSString out of the AJNMessageArguments that are in the array, here is that method:
+ (NSString*)getStringFromMessageArgument:(AJNMessageArgument*)msgarg
{
char *charStr;
QStatus status = [msgarg value:#"s", &charStr];
if (status != ER_OK) {
NSLog(#"Error");
}
NSString *str = [NSString stringWithFormat:#"%s", charStr];
return str;
}
Happy AllJoyn-ing.
(I don't know how to use or what to call this, so I can't think of a better title).
I am using the PNChart classes, specifically PNBarChart. It requires that an array of numbers are given to the yValues.
I need to format this, for which it has PNYLabelFormatter. =
typedef NSString *(^PNYLabelFormatter)(CGFloat yLabelValue);
So when I type the following, what do I fill in the gap with?
[barChart setYLabelFormatter:GAP HERE];
I recognise I need to nest my formatting in this bit, but I don't know what to call this or how to format it.
You can find how to use this lib from examples.
$ pod try PNChat and you'll get demo project.
Open PCChartViewController.m look in block started with
else if ([self.title isEqualToString:#"Bar Chart"]) {
...
self.barChart.yLabelFormatter = ^(CGFloat yValue){
CGFloat yValueParsed = yValue;
NSString * labelText = [NSString stringWithFormat:#"%1.f",yValueParsed];
return labelText;
};
self.barChart setXLabels:#[#"SEP 1",#"SEP 2",#"SEP 3",...];
[self.barChart setYValues:#[#1,#24,#12,#18,#30,#10,#21]];
I'm using NSXMLParser for parsing XML to my app and having a problem with the encoding type. For example, here is one of the feeds coming in. It looks similar to this"
\U2026Some random text from the xml feed\U2026
I am currently using the encoding type:
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
Which encoding type am I suppose to use for converting \U2026 into a ellipse (...) ??
The answer here is you're screwed. They are using a non-standard encoding for XML, but what if they really want the literal \U2026? Let's say you add a decoder to handle all \UXXXX and \uXXXX encodings. What happens when another feed want the data to be the literal \U2026?
You're first choice and best bet is to get this feed fixed. If they need to encode data, they need to use proper HTML entities or numeric references.
As a fallback, I would isolate the decoder away from the XML parser. Don't create a non-conforming XML parser just because your getting non-conforming data. Have a post processor that would only be run on the offending feed.
If you must have a decoder, then there is more bad news. There is no built in decoder, you will need to find a category online or write one up yourself.
After some poking around, I think Using Objective C/Cocoa to unescape unicode characters, ie \u1234 may work for you.
Alright, heres a snippet of code that should work for any unicode code-point:
NSString *stringByUnescapingUnicodeSymbols(NSString *input)
{
NSMutableString *output = [NSMutableString stringWithCapacity:[input length]];
// get the UTF8 string for this string...
const char *UTF8Str = [input UTF8String];
while (*UTF8Str) {
if (*UTF8Str == '\\' && tolower(*(UTF8Str + 1)) == 'u')
{
// skip the next 2 chars '\' and 'u'
UTF8Str += 2;
// make sure we only read 4 chars
char tmp[5] = { UTF8Str[0], UTF8Str[1], UTF8Str[2], UTF8Str[3], 0 };
long unicode = strtol(tmp, NULL, 16); // remember that Unicode is base 16
[output appendFormat:#"%C", unicode];
// move on with the string (making sure we dont miss the end of the string
for (int i = 0; i < 4; i++) {
if (*UTF8Str == 0)
break;
UTF8Str++;
}
}
else
{
if (*UTF8Str == 0)
break;
[output appendFormat:#"%c", *UTF8Str];
}
UTF8Str++;
}
return output;
}
You should simple replace literal '\U2026' on a quotation, then encode it with NSUTF8StringEncoding encodind to NSData