Working With JSON: A Beginner’s Guide

Since 2006, the popularity of JSON has steadily risen among programmers, data analysts, app developers (mobile and web) and other techies around the world. A preliminary overview of some key features of JSON has been presented here.

When JSON services were launched in the final quarter of 2006, few people had envisaged that it would emerge as a viable alternative to XML – within a relatively short span of time. For storing information via programming, and to facilitate data-transfer between the client and server sides, XML still remains the first choice – although JSON is catching up fast. In particular, it has been found that one out of every four mobile app developers prefer using JSON over the relatively more complicated XML. If you too wish to start using JSON (JavaScript Object Notation), the following would serve as a handy guide:

1. What types of data can be stored on JSON? – Two alternative structures – arrays and objects – can be built on JSON. The total number of data types supported on the information-storing system is five. You can store strings, objects, numbers, arrays and Boolean (i.e., true vs false) information on it.

2. How is information stored in JSON? – All data, values and attributes in JSON are have to be stored by creating separate objects for them. You can declare any number of properties inside an object. Multiple property pairings have to be comma-separated. Most professional web app and mobile app developers feel that this systematic manner of storing information is one of the key advantages of the framework.

3. How can you check for code errors? – Program debugging becomes a rather straightforward task, when you use JSON API (preferably, integrated with Google Analytics). Functions can be called to check all probable errors in the XHR responses that are generated. You can even keep track of the frequency of same/similar errors, with the help of customized reports. Not surprisingly, JSON is rapidly becoming a favorite among app testers too!

4. Using nested objects – Apart from multiple properties within one object, JSON supports the creation of nested objects as well. The same property pairings have to be declared for each of the nested items – and an alert () function is required to access and display any particular property. Remember to close all the second brackets/curly brackets at the end of each nested object.

5. How to load JSON on application codes? – This is most easily done via AJAX, by creating an $ajax() method. All the feed items would get stored in the JavaScript Object Notation format, and you can export them on your web browser as well (not recommended though). The dataType you select should be ‘jasonp’. Provided that the method is error-free, getting and retrieving data from external files can be done in a seamless manner indeed. The getJSON() method is used for calling data in the right format from the server.

6. All response codes are not similar – The XHR response codes, obtained through the jQuery.get method vary with the type of values and properties you use in the objects and arrays. There might even be random variations in the responses, in certain cases. For instance, if a string is passed without any value, it would probably not be shown in the XHR file. The broad framework of JSON responses are same, but you need to note down the differences across projects.

7. What is the eval() function? – Javascript coders from mobile app development companies in India and abroad need to be familiar with the eval () function. It is used to process JSON codes in JavaScript – which ensures that they are interpreted in the correct manner (and not treated as simple text lines). However, a flipside of using this function is that it slows down the overall loading process. Developers have to be wary about hacker attacks on the converted JavaScript codes too.

8. Do you need an XHTML page? – JSON cannot be used without a XHTML page. You need to make a ‘doctype’ declaration at the very start of the code. In addition, you will also require Javascript file and jQuery. For best coding results, make sure that the jQuery you are using is of the latest version.

9. Cross-domain usage – Technicians from mobile app companies also highlight the ‘jsonp’ function as yet another high point about JSON. This method basically initiates a systematic callback function – helping programmers get back the codes on the domain(s) of their choice. Most of the alternatives of JSON do not have this user-friendly feature.

10. Presence of the server is critical for receiving JSON – Just as APACHE does, JSON also throws up a 503 Error code, in case the server has not been called in program. You need to be particularly careful while working with proxy servers. Remember, the response need not necessarily contain JSON – the server-side has to be properly checked to ensure that.

11. Is JSON tough to learn? – When you are in charge of coding for web, Android or iPhone app development, you can hardly expect any aspect to be ridiculously easy. However, JSON has a relatively short learning curve, and is almost universally referred to be extremely user-friendly. Apart from JavaScript, it is compatible with multiple program languages too.

12. You can use the JSON Lightbox – JSON is one information storing and parsing tool which helps in adding to the style of the final output as well. After the processing stage, and above the dataType declaration, you need to call the addLB() function, to add a nice lightbox effect to your code. It is not a necessary part of the code – but is often used by professional developers.

Many newbies tend to make mistakes while creating AJAX requests and/or calling functions (e.g., loadFlickr() ) – and it would not be advisable to try to rush through these stages. Combined with JavaScript (after the string verification), JSON is a very powerful and yet simple data storage and calling method for programming and app development. If the recent trends are anything to go by, it is probably well on its way to overtake XML in terms of popularity among developers.