Transform - aalfiann/fly-json-odm GitHub Wiki

Sometimes instead of updating or modifying whole data json, it's better to restructuring again the json itself.

jsonTransform is for restructuring and performing operations on JSON.
This feature is inspired from the original project by node-json-transform.

Usage

• Basic Example
• Advanced Example
• Multi Template Example
• Context Example

Basic Example

var FlyJson = require("fly-json-odm"); // in browser doesn't need this line
var nosql = new FlyJson();

First we need some data.

var data = {
	posts : [
		{
			title : "title1",
			description: "description1",
			blog: "This is a blog.",
			date: "11/4/2013",
			extra : {
				link : "http://goo.cm"
			},
			list1:[
				{
					name:"mike"
				}
			],
			list2:[
				{
					item: "thing"
				}
			],
			clearMe: "text"
		}
	]
};

The map defines how the output will be structured and which operations to run.

var map = {
	list : 'posts',
	item: {
		name: "title",
		info: "description",
		text: "blog",
		date: "date",
		link: "extra.link",
		item: "list1.0.name",
		clearMe: "",
		fieldGroup: ['title', 'extra']
	},
	operate: [
		{
			run: "Date.parse", on: "date"
		},
		{
			run: function(val) { return val + " more info"}, on: "info"
		}
	],
	each: function(item){
		// make changes
		item.iterated = true;
		return item;
	}
};

You can read this as follows:

• Get the array of objects in "posts".
• Map the name to title, info to description etc.
• Run Data.parse on the date value.
• Run each function on all items after mapping and operations.

Run it synchronously

var result = nosql.jsonTransform(data, map).make();
console.log(result);

or asynchronously (callback style)

nosql.promisify((builder) => {return builder}).then((table) => {
  var result = table.jsonTransform(data, map).make();
  console.log(result);
});

or asynchronously (async/await style)

const result = await nosql.promisify((builder) => {return builder}).then((table) => {
  return table.jsonTransform(data, map).make();
});

console.log(result);

The expected output.

[
	{
		name : "title1",
		info: "description1",
		text: "This is a blog.",
		date: 1383544800000,
		link: "http://goo.cm",
		info: "mike more info",
		clearMe: "",
		fieldGroup: ['title1', { link : "http://goo.cm" }],
		iterated: true
	}
]

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Advanced Example

var map = {
	list: 'items',
	item: {
		id: 'id',
		sku: 'sku',
		zero: 'zero',
		toReplace: 'sku',
		errorReplace: 'notFound',
		simpleArray: ['id', 'sku','sku'],
		complexArray: [ {node: 'id'} , { otherNode:'sku' } , {toReplace:'sku'} ],
		subObject: {
			node1: 'id',
			node2: 'sku',
			subSubObject: {
				node1: 'id',
				node2: 'sku',
			}
		},
		remove: ['unwanted']
	},
	defaults: {
		"missingData": true
	},
	operate: [
		{
			run: (val) => 'replacement',
			on: 'subObject.subSubObject.node1'
		},
		{
			run: (val) => 'replacement',
			on: 'errorReplace'
		},
		{
			run: (val) => 'replacement',
			on: 'toReplace'
		},
			{
			run: (val) => 'replacement',
			on: 'simpleArray.2'
		},
		{
			run: (val) => 'replacement',
			on: 'complexArray.2.toReplace'
		}
	]
};

var object = {
	items:[
		{
			id: 'books',
			zero: 0,
			sku:'10234-12312',
			unwanted: true
		}
	]
};

var result = nosql.jsonTransform(data, map).make();

The expected output.

[
	{
	    "id": "books",
	    "sku": "10234-12312",
	    "zero": 0,
	    "toReplace": "replacement",
	    "errorReplace": "replacement",
	    "simpleArray": [
	        "books",
	        "10234-12312",
	        "replacement"
	    ],
	    "complexArray": [
	        {
	            "node": "books"
	        },
	        {
	            "otherNode": "10234-12312"
	        },
	        {
	            "toReplace": "replacement"
	        }
	    ],
	    "subObject": {
	        "node1": "books",
	        "node2": "10234-12312",
	        "subSubObject": {
	            "node1": "replacement",
	            "node2": "10234-12312"
	        }
	    },
		"missingData": true
	}
]

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Multi-template Example

var data = {
    products: [{
        id: 'books0',
        zero: 0,
        sku: '00234-12312',
        subitems: [
            { subid: "0.0", subsku: "subskuvalue0.0" },
            { subid: "0.1", subsku: "subskuvalue0.1" }
        ]
    }, {
        id: 'books1',
        zero: 1,
        sku: '10234-12312',
        subitems: [
            { subid: "1.0", subsku: "subskuvalue1.0" },
            { subid: "1.1", subsku: "subskuvalue1.1" }
        ]
    }]
};

var baseMap = {
	'list': 'products',
	'item' : {
		'myid': 'id',
		'mysku': 'sku',
		'mysubitems': 'subitems'
	},
    operate: [
        {
            'run': function(ary) { 
            	return nosql.jsonTransform({list:ary}, nestedMap).make();
            }, 
            'on': 'mysubitems'
        }
    ]
};

var nestedMap = {
	'list': 'list',
	'item' : {
		'mysubid': 'subid',
		'mysubsku': 'subsku'
	}
};

var result = nosql.jsonTransform(data, baseMap).make();

The expected output.

[
	{
	    "myid": "books0",
	    "mysku": "00234-12312",
	    "mysubitems": [
	    	{ "mysubid": "0.0", "mysubsku": "subskuvalue0.0" }, 
	    	{ "mysubid": "0.1", "mysubsku": "subskuvalue0.1"}
	    ]
	}, 
	{
	    "myid": "books1",
	    "mysku": "10234-12312",
	    "mysubitems": [
	    	{ "mysubid": "1.0", "mysubsku": "subskuvalue1.0" }, 
	    	{ "mysubid": "1.1", "mysubsku": "subskuvalue1.1" }
	    ]
	}
]

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Context Example

First we need some data.

    var data = {
        posts : [
            {
                title : "title1",
                description: "description1"
            }
        ]
    };

The map defines how the output will be structured and which operations to run.

    var map = {
        list : 'posts',
        item: {
            name: "title",
            info: "description"
        },
        operate: [
            {
                run: function(val, context) { return val + " more info for" + context.type},
                on: "info"
            }
        ],
        each: function(item, index, collection, context){
            // make changes
            item.type = context.type;
            return item;
        }
    };

Run it

    var context = { type: 'my-type' };
    var result = nosql.jsonTransform(data, map).make(context);
    console.log(result);

The expected output.

    [
        {
            name : "title1",
            info: "description1 more info for my-type",
            type: 'my-type'
        }
    ]

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