Get specific Value between Javascript Function by NSRegularExpression? - iphone

Question

I am creating a project for learning purpose:
FOR INFO : I have not used UIWebView
In my project I got HTML data(content) from server. This data contains all information about places(from google map). For getting specific data from HTML content I need to parse HTML. I parse HTML using Hpple. And I could successfully parse HTML to get specific data (Such as name,address…etc), but when I need to parse latitude and longitude from HTML content, I am confused about how to get latitude and longitude of places, because those are part of Javascript. I mean these latitude and longitude data are available in Javascript's functions.
Javascript content that I got from Server: (My limitation is that, I can only put piece of javascript code bacause this code is very very long)
function()
{
window.gHomeVPage=
{
title:'Hostel, Bhavnagar, Gujarat, India - Google Maps',url:'/?q\\x3dHostel,+Bhavnagar,+Gujarat,+India\\x26hq\\x3dHostel,\\x26hnear\\x3dBhavnagar,+Gujarat,+India\\x26t\\x3dm\\x26ie\\x3dUTF8',urlViewport:false,ei:'jp8tUb3uNK2ciAeQroGACw',
form:{
selected:'q',
q:{q:'Hostel, Bhavnagar, Gujarat, India',what:'Hostel,',near:'Bhavnagar, Gujarat, India'},d:{saddr:'',daddr:'',dfaddr:'Bhavnagar, Gujarat, India'},geocode:''},
query:{type:'l'},viewport:{center:{lat:21.757528,lng:72.15303},span:{lat:0.034314,lng:0.039956},zoom:14,mapType:'m',source:0},modules:['','strr','pphover','act_s','appiw','rst'],
overlays:{sxcar:false,
markers:
[{id:'A',cid:'7569356420090555589',latlng:{lat:21.747064,lng:72.169678},image:'http://maps.gstatic.com/intl/en_ALL/mapfiles/markers2/circleA.png',sprite:{width:20,height:34,top:0,image:'http://maps.gstatic.com/mapfiles/markers2/red_circle_markers_A_J2.png'},icon_id:'A',ext:{width:20,height:34,shadow:'http://maps.gstatic.com/intl/en_ALL/mapfiles/circle-shadow45.png',shadow_width:37,shadow_height:34,mask:false},drg:true,laddr:'Shree Sahajanand Girls Ptc Hostel, Ghogha Road, Bhavnagar, Gujarat 364001, India',geocode:'CfYWJFjKQj0mFXjVSwEdzjhNBCmN5-3pPlpfOTHF7NFVj8ELaQ',sxti:'Shree Sahajanand Girls Ptc Hostel',name:'Shree Sahajanand Girls Ptc Hostel',infoWindow:{title:'Shree Sahajanand Girls Ptc \\x3cb\\x3eHostel\\x3c/b\\x3e',addressLines:['Ghogha Road','Bhavnagar, Gujarat 364001, India'],phones:[{number:'0278 2562529'}],basics:'\\x3cdiv transclude\\x3d\\x22iw\\x22\\x3e\\x3c/div\\x3e',moreInfo:'more info',place_url:'http://maps.google.com/local_url?dq\\x3dHostel,+Bhavnagar,+Gujarat,+India\\x26q\\x3dhttps://plus.google.com/106028699675431268945/about%3Fhl%3Den\\x26s\\x3dANYYN7mCKtIBT1JPxwi6G2b9gVDdCuVyyA',zrvOk:true,loginUrl:'https://www.google.com/accounts/ServiceLogin?service\\x3dlocal\\x26hl\\x3den\\x26nui\\x3d1\\x26continue\\x3dhttp://maps.google.com/maps/place%3Fcid%3D7569356420090555589%26q%3DHostel,%2BBhavnagar,%2BGujarat,%2BIndia%26t%3Dm%26cd%3D1%26cad%3Dsrc:ppwrev%26ei%3Djp8tUb3uNK2ciAeQroGACw%26action%3Dopenratings',lbcurl:'http://www.google.com/local/add/choice?hl\\x3den\\x26gl\\x3dIN\\x26latlng\\x3d7569356420090555589\\x26q\\x3dHostel,\\x26near\\x3dBhavnagar,+Gujarat,+India',link_jsaction:''},ss:{edit:true,detailseditable:true,deleted:false,rapenabled:true,mmenabled:true},b_s:2,approx:true,elms:[4,1,6,2,12,1,9,1,5,2,11]
}
}
Here in above code I want to get value of lat: and lon: from latlng:{lat:21.747064,lng:72.169678}
For getting it from javascript, I googled and found that I need to use NSRegularExpression class for get specific matches(of Data) form content.
Then I tried with following code
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"(?-imsx:latlng:)" options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *arrayOfAllMatches = [regex matchesInString:locationStr options:0 range:NSMakeRange(0, [locationStr length])];
for (NSTextCheckingResult *match in arrayOfAllMatches)
{
NSString* substringForMatch = [locationStr substringWithRange:match.range];
NSLog(#"%#",substringForMatch);
}
I got output in console like this:
2013-02-28 11:35:25.051 MapExample[949:13d03] latlng:
2013-02-28 11:35:25.766 MapExample[949:13d03] latlng:
2013-02-28 11:35:26.208 MapExample[949:13d03] latlng:
2013-02-28 11:35:26.799 MapExample[949:13d03] latlng:
2013-02-28 11:35:27.303 MapExample[949:13d03] latlng:
2013-02-28 11:35:27.722 MapExample[949:13d03] latlng:
How can I get content of searched node from NSRegularExpression ?

Answer 1

If you really want to use a regular expression, this following pattern should work:
NSString *pattern = #"latlng:\\{lat:([0-9.]+),lng:([0-9.]+)\\}";
[0-9.]+ matches one or more characters which are a digit or ., and the parentheses around it make it a "capture group", so that the part of the string that matches this part of the pattern is available using rangeAtIndex:.
To verify this, I have added the exact input data from your question as a resource file "data.txt" to my test application, and loaded that data with
NSURL *url = [[NSBundle mainBundle] URLForResource:#"data.txt" withExtension:nil];
NSError *error;
NSString *locationStr = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
and then parsed the string with the regular expression
NSString *pattern = #"latlng:\\{lat:([0-9.]+),lng:([0-9.]+)\\}";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:&error];
NSArray *matches = [regex matchesInString:locationStr options:0 range:NSMakeRange(0, [locationStr length])];
for (NSTextCheckingResult *match in matches)
{
NSString *lat = [locationStr substringWithRange:[match rangeAtIndex:1]];
NSString *lng = [locationStr substringWithRange:[match rangeAtIndex:2]];
NSLog(#"latidude = %#, longitude = %#", lat, lng);
}
Output:
latidude = 21.747064, longitude = 72.169678

Answer 2

While not a direct answer to your question, there's actually an easier way to do this, using UIWebView:
+(NSString *)valueFromJSON:(NSString *)json andKey:(NSString *)key {
UIWebView webView = [[UIWebView alloc] init];
return [webView stringByEvaluatingJavaScriptFromString:[NSString withFormat:#"(function(){ var v = %#; return var.%#; }())", json, key]];
}
I'll apologize in advance for any syntax errors I've invariably made due to not being on my Mac and it being rather late. If you call this code repeatedly, it might be wise not to initialize a new WebView every time. This exploits the ability of WebKit's Javascript engine to do easy JSON parsing for you. Replace the return in the Javascript function to match your data structure.