定义参数Json或对象

Question

I've method that draw some controllos on the screen,now I want that this method will be an API and make it more daynamic in order to provide to the user ability to decide which control he want to draw on the screen. I thougt to ask to provide some json structure but not sure if its better then object...,any suggestion

eg

withSection1 true
withSection2  false
withSecttion3 false
withSection4 true
.....

but by default to add some parameter if the user want to draw all instead of provide all the data(section's).so I not sure how to build it.

update

Assume I use a json for the section's How should I put the defualt in the method signature if user want by deafult to draw all the controlles

{
    "withSection1": 'true'
    "withSection2": 'true'
    "withSection3": 'false'
    "withSection4": 'true'

}

so the method signature will be like drawScreen(jsonStr)

Answer 1

The main difference between object (if you want to use simple objects whitout playing with the prototype) and JSON is you won't be able to use functions in JSON.

If you don't need functions (never), you should certainly go for JSON because it is more restrictive and it is almost always a good thing to prevent user from doing something you don't want. This also can help you to use it with another langage if you plan to do that.

However, I created a javascript/node.js framework (a link is in my profile if you want to see an example) where I extensively use javascript objects for configuration because it is really more modular (you can factorize some code in variables, merge some files together without doing a lot of work, you win a little performance on interpretation, ...)! Oh I forgot something important! You cannot use comment in JSON.

Here some trivial examples (don't code like that :):

Object

// foo.js
var foo = {
    foo: 1
};

---

// bar.js
var bar = {
    bar: function() { return 2; }
};

---

// merge.js
var obj = merge(foo, bar); // Implement merge function once.

JSON

foo.json (no comments)

{
    "foo": 1
}

---

bar.json (no comments)

{
    "bar": 'no functions'
}

---

// merge.js
// You have to get the JSON files, then parse them (JSON.parse in javascript), then merge them.

As I said you can see more important use of objects following the link in my profile.

UPDATE

If you want to set default value and/or which field and which type of field you want in your JSON, you certainly should have another JSON or object describing your structure. In the framework, the input of the user is processed from a contract file for example:

var jsonConfiguration = '{"withSection1": false}';

var contract = {
    withSection1: {
        type: 'boolean',
        default: true
    },
    withSection2: {
        type: 'boolean',
        default: true
    },
    withSection3: {
        type: 'boolean',
        default: false
    },
    withSection4: {
        type: 'boolean',
        default: true
    }
}

// Check types, add default values if needed, ...
var configuration = processConfiguration(jsonConfiguration, contract);

drawScreen(configuration);

function processConfiguration(jsonConfiguration, contract) {
    var configuration = JSON.parse(jsonConfiguration),
        processedConfiguration = {}
    ;

    for (var key in contract) {
        if (undefined === configuration[key]) {
            processedConfiguration[key] = contract[key].default;
        } else {
            processedConfiguration[key] = configuration[key];
        }
    }

    return processedConfiguration;
}