Defining Mongoose Schema from JSON File

Question

I want to define my mongoose scheme from a JSON file. This is my JSON file structure:

   {    
        "default": [
            {
                "item": "productTitle",
                "label": "Product Title",
                "note": "e.g Samsung GALAXY Note 4",
                "type": "text",
                "required": "Product Name cannot be blank..."
            },
            {
                "item": "productCode",
                "label": "Product Code",
                "type": "text",
                "required": "Product Code cannot be blank..."
            }    
        ]}

This is my node.js model:

// Load the module dependencies
var mongoose = require('mongoose'),
Schema = mongoose.Schema;

var fs = require('fs');
var file = __dirname + '/product.server.model.json';

// Read the json file
fs.readFile(file, 'utf8', function (err, data) {

data = JSON.parse(data);

var productJson = {};
for(var  i = 0; i < data.default.length; i++) {

    productJson[data.default[i].slug] = {
        type: 'String',
        required: data.default[i].required,
        default: '',
        trim: true
    }

}

});

// Define a new 'ProductSchema'
var ProductSchema = new Schema(
   // Here I want to put JSON Data 'productJson'
);

// Create the 'Product' model out of the 'ProductSchema'
mongoose.model('Product', ProductSchema);    

I tried all possible ways to determine the mongoose scheme from the JSON data 'productJson'. But if I do not predetermine my mongoose pattern, it does not work. Is there a way to determine the mongoose pattern from the JSON data in my model? Any suggestion please?

Answer 1

fs.readFile is an asynchronous function, which means that it returns immediately and then provides its results to the caller through the callback function that you provide as the third parameter.

, productJson, . .

fs.readFile(file, 'utf8', function (err, data) {

    data = JSON.parse(data);

    var productJson = {};
    for(var  i = 0; i < data.default.length; i++) {

        // Changed .slug to .item here as I don't see slug in the JSON
        productJson[data.default[i].item] = {
            type: 'String',
            required: data.default[i].required,
            default: '',
            trim: true
        }
    }

    // Define a new 'ProductSchema'
    var ProductSchema = new Schema(productJson);

    // Create the 'Product' model out of the 'ProductSchema'
    mongoose.model('Product', ProductSchema);
});

, , fs.readFileSync . /, , , .

var data = fs.readFileSync(file, 'utf8');
data = JSON.parse(data);

var productJson = {};
for(var  i = 0; i < data.default.length; i++) {

    // Changed .slug to .item here as I don't see slug in the JSON
    productJson[data.default[i].item] = {
        type: 'String',
        required: data.default[i].required,
        default: '',
        trim: true
    }
}

// Define a new 'ProductSchema'
var ProductSchema = new Schema(productJson);

// Create the 'Product' model out of the 'ProductSchema'
mongoose.model('Product', ProductSchema);