Parsing HTML code of a page, contained in an JSON key-value pair with TFHpple in iOS

Question

I'm making a native iOS app of my team's project using it's API. API has three main methods: to get user's profile information, his diary and certificate table. Last method returns to me JSON data with HTML code of a table. It looks like this

{"html":"<table class=\"table term-marks\" cellspacing=\"0\" cellspadding=\"0\"> <thead> <tr> <td>\u041f\u0440\u0435\u0434\u043c\u0435\u0442<\/td> <td colspan=\"10\">\u041e\u0446\u0435\u043d\u043a\u0438<\/td><td width=\"60px\">\u0421\u0440\u0435\u0434\u043d\u0438\u0439 <br\/>\u0431\u0430\u043b\u043b<\/td> <td width=\"60px\">\u0421\u0440\u0435\u0434\u043d\u0438\u0439 <br\/>\u043f\u043e \u043a\u043b\u0430\u0441\u0441\u0443<\/td> <td width=\"60px\">\u0421\u0440\u0435\u0434\u043d\u0438\u0439 <br\/>\u043f\u043e \u043f\u0430\u0440\u0430\u043b\u043b\u0435\u043b\u0438<\/td><td width=\"60px\">\u0418\u0442\u043e\u0433\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430<\/td> <\/tr> <\/thead> <tbody> <tr> <td>\u0410\u043d\u0433\u043b\u0438\u0439\u0441\u043a\u0438\u0439<\/td> <td>5<\/td> <td>5<\/td> <td>5<\/td> <td>4<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.60<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0411\u0438\u043e\u043b\u043e\u0433\u0438\u044f<\/td> <td>3<\/td> <td>5<\/td> <td>5<\/td> <td>5<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.50<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0413\u0435\u043e\u0433\u0440\u0430\u0444\u0438\u044f<\/td> <td>5<\/td> <td>4<\/td> <td>3<\/td> <td>2<\/td> <td>3<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>3.40<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0442\u0438\u043a\u0430 \u0438 \u0418\u041a\u0422<\/td> <td>5<\/td> <td>5<\/td> <td>4<\/td> <td>5<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.75<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0418\u0441\u043a\u0443\u0441\u0441\u0442\u0432\u043e<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0418\u0441\u0442\u043e\u0440\u0438\u044f<\/td> <td>5<\/td> <td>2<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>3.50<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u041b\u0438\u0442\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/td> <td>4<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.00<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u041c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430<\/td> <td>4<\/td> <td>5<\/td> <td>3<\/td> <td>5<\/td> <td>4<\/td> <td>4<\/td> <td>5<\/td> <td>2<\/td> <td>3<\/td> <td>5<\/td> <td>4.00<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u041e\u0431\u0449\u0435\u0441\u0442\u0432\u043e\u0437\u043d\u0430\u043d\u0438\u0435<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.00<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0420\u0443\u0441\u0441\u043a\u0438\u0439 \u044f\u0437\u044b\u043a<\/td> <td>5<\/td> <td>5<\/td> <td>4<\/td> <td>5<\/td> <td>5<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.80<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0422\u0430\u0442\u0430\u0440\u0441\u043a\u0430\u044f \u043b\u0438\u0442\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0422\u0430\u0442\u0430\u0440\u0441\u043a\u0438\u0439 \u044f\u0437\u044b\u043a<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.00<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0424\u0438\u0437\u0438\u043a\u0430<\/td> <td>3<\/td> <td>4<\/td> <td>5<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.00<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0424\u0438\u0437\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u043a\u0443\u043b\u044c\u0442\u0443\u0440\u0430<\/td> <td>5<\/td> <td>4<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.50<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr> <td>\u0425\u0438\u043c\u0438\u044f<\/td> <td>4<\/td> <td>5<\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td><\/td> <td>4.50<\/td><td><\/td> <td><\/td> <td><\/td> <\/tr> <tr><td colspan=\"11\"><strong>\u0418\u0422\u041e\u0413\u041e<\/strong><\/td><td>3.88<\/td> <td>0<\/td> <td>0<\/td> <td>-<\/td><\/tr> <\/tbody> <\/table>"}

I've tried to create an NSDictionary with this JSON data and get NSData from there like this:

NSData *htmlData = [[NSData alloc] init];
NSDictionary *jsonDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:nil]; // responseData contains API response
htmlData = [jsonDictionary objectForKey:@"html"];
TFHpple *parser = [TFHpple hppleWithHTMLData:htmlData];
NSArray *tableRows = [mainParser searchWithXPathQuery:@"//tr/td"]

But I'm getting the same error like here. But I can't use the solution from there, because I don't have an URL to the table, I only have it's html code. How can I parse it?

There is no need to alloc/init htmlData; You are just waisting CPU there. That is not your problem, of course. — Hermann Klecker, May 06 '14 at 13:53
@HermannKlecker thanks for an advise! I'm just 16 years old and I'm a beginner to Obj-C programming :) Will try your solution now. — khabiroff, May 06 '14 at 16:58

Hermann Klecker · Accepted Answer · 2014-05-06T14:01:59.590

You are receiving an NSString object from [jsonDictionary objectForKey:@"html"];

Regardless how you actually declared the receiving variable, NSData in this case, it will be assigned what the method actually returns. And that is an NSString in this case.

In general it is advisable to receive the data in a variable of type id first and then check its class using isKindOfClass and then go from there.

NSData *htmlData;
NSDictionary *jsonDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:nil];
id nextElement = [jsonDictionary objectForKey:@"html"];
if (id isKindOfClass:[NSString class]) {
  htmlData = [(NSString*)id dataUsingEncoding:NSUTF8StringEncoding];
} else {
   // Deal with the error or cover other classes accordingly 
} 
TFHpple *parser = [TFHpple hppleWithHTMLData:htmlData];
NSArray *tableRows = [mainParser searchWithXPathQuery:@"//tr/td"]

Parsing HTML code of a page, contained in an JSON key-value pair with TFHpple in iOS

1 Answers1