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iOS

Posted by RASHU BHATNAGAR
RASHU BHATNAGAR
Courses Plus Student 2,669 Points

Downloading and Parsing JSON Data

Hi guys i am referring to this video: http://teamtreehouse.com/library/build-a-blog-reader-iphone-app-2/getting-data-from-the-web/downloading-and-parsing-json-data-2

It is regarding the extra credit question. I am some how not able to get what are they asking to be displayed on the blog reader table view . I did every thing as i was taught and the app uptil now in the simulator works just fine. But the extra credit question i am not able to get what exactly they want us to do. Please help

3 Answers

RASHU BHATNAGAR
PLUS
RASHU BHATNAGAR
Courses Plus Student 2,669 Points
RASHU BHATNAGAR
RASHU BHATNAGAR
Courses Plus Student 2,669 Points

Thanks Natacha S. for the prompt reply.

This is what i am doing in the - (void)viewDidLoad method. and I am still not able to get what am i doing wrong.

 NSURL *blogURL=[NSURL URLWithString:@"https://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=JSON"];
    NSData *jsonData=[NSData dataWithContentsOfURL:blogURL];
//  NSLog(@"%@",jsonData);
    NSError *error=nil;

    NSDictionary *dataDictionary=[NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
     NSLog(@"%@",dataDictionary);

    self.blogPosts=[dataDictionary objectForKey:@"results"];

The app is working fine in the simulator, i mean there are no errors. but no data is showing on the table view in simulator.

Please help...

Amit Bijlani
Amit Bijlani
Treehouse Guest Teacher
Amit Bijlani
Amit Bijlani
Treehouse Guest Teacher

You have to look at the structure of the data that is presented to you.

{
    "responseData": {
        "results": [
            {
                "GsearchResultClass": "GwebSearch",
                "unescapedUrl": "http://www.json.org/",
                "url": "http://www.json.org/",
                "visibleUrl": "www.json.org",
                "cacheUrl": "http://www.google.com/search?q=cache:l_yxMvC_ErgJ:www.json.org",
                "title": "<b>JSON</b>",
                "titleNoFormatting": "JSON",
                "content": "<b>JSON</b> (JavaScript Object Notation) is a lightweight data-interchange format. It is \neasy for humans to read and write. It is easy for machines to parse and generate."
            },
            {
                "GsearchResultClass": "GwebSearch",
                "unescapedUrl": "http://www.json.org/js.html",
                "url": "http://www.json.org/js.html",
                "visibleUrl": "www.json.org",
                "cacheUrl": "http://www.google.com/search?q=cache:y1JKLz1ap_IJ:www.json.org",
                "title": "<b>JSON</b> in JavaScript",
                "titleNoFormatting": "JSON in JavaScript",
                "content": "<b>JSON</b> is a subset of the object literal notation of JavaScript. Since <b>JSON</b> is a \nsubset of JavaScript, it can be used in the language with no muss or fuss."
            }           
        ],
        "cursor": {
            "resultCount": "4,100,000",
            "pages": [
                {
                    "start": "0",
                    "label": 1
                }                
            ],
            "estimatedResultCount": "4100000",
            "currentPageIndex": 0,
            "moreResultsUrl": "http://www.google.com/search?oe=utf8&ie=utf8&source=uds&start=0&hl=en&q=JSON",
            "searchResultTime": "0.12"
        }
    },
    "responseDetails": null,
    "responseStatus": 200
}

As you can see above you have a dictionary which contains a key called responseData within that you have the results. So you can't directly access the results. You would need to use the method valueForKeyPath.

    self.blogPosts = [dataDictionary valueForKeyPath:@"responseData.results"];
Natacha S
Natacha S
11,561 Points
Natacha S
Natacha S
11,561 Points

They want you to use a different set of data to import into your blog reader. For example they'd like to see the data returned by a random google search, that you determine by modifying what comes after the "q="

RASHU BHATNAGAR
PLUS
RASHU BHATNAGAR
Courses Plus Student 2,669 Points
RASHU BHATNAGAR
RASHU BHATNAGAR
Courses Plus Student 2,669 Points

Thanks for replying back Amit. It works fine now.... Thanks once again