Schema Analizer

W ngsi-parser helps you to manage your Data Models like used in FIWARE, ngsi-parser can analize if the entity complies with the specified model and identify its errors, to do it you need the JSON Schema of this Data Model provided or you can build some.

You can know about JSON Schemas in JSON Schema.

Importing your JSON Schema

You can import your JSON schema importing a JSON from a file or from a repository using the help of ocb-sender.

Importing From a JSON File

    var ngsi = require('ngsi-parser');
    var mySchema = require('mySchema.json');
    ngsi.setModel({
        mySchema : mySchema
    });

Importing from a remote repository

    var ngsi = require('ngsi-parser');
    ngsi.setModel({
        myRemoteSchema : 'https://yourdatamodels.com/myRemote'
    });

Importing several schemas from different sources

    var ngsi = require('ngsi-parser');
    var mySchema = require('mySchema.json');
    ngsi.setModel({
        mySchema : mySchema,
        myRemoteSchema : 'https://yourdatamodels.com/myRemote',
        AlertModel : 'https://raw.githubusercontent.com/smartsdk/dataModels/master/Alert/schema.json',
        anotherModel : require('anotherSchema.json')
    });

Using your Data Models Schemas

To use the schemas imported from a JSON file only you need to specify the name with which you entered it to ngsi-parser and it will return you one array with the errors found.

    var ngsi = require('ngsi-parser');
    var mySchema = require('mySchema.json');
    ngsi.setModel({
        mySchema : mySchema
    });
    var entity = { 
        id :'Room1',
        type:'Room',
        temperature : 50, 
        dateStamp :  new  Date()  
    };
    let errors  = ngsi.verifyModel('mySchema', entity);
    if (errors.length === 0 ){
        console.log("The entity it's OK")
    }else {
        errors.map(console.log)
    }

To use Schemas from a remote repository is necesary download it, is because you need use ocb-sender, and in this case the method ngsi.verifyModel() becomes to a promise.

    var ngsi = require('ngsi-parser');
    var ocb = require('ocb-sender');
    ngsi.setModel({
        myRemoteSchema : 'https://yourdatamodels.com/myRemote',
    });
    var entity = { 
        id :'Room1',
        type:'Room',
        temperature : 50, 
        dateStamp :  new  Date()  
    };
    ngsi.verifyModel('myRemoteSchema', entity, ocb)
    .then((errors) => { 
        if (errors.length === 0 ){
            console.log("The entity it's OK")
        }else {
            errors.map(console.log)
        }
    })

Use without storing the JSON schema

    var ngsi = require('ngsi-parser');
    var ocb = require('ocb-sender');
    ngsi.verifyModel('https://yourdatamodels.com/myRemote', entity ,cb)
    .then((errors) => { 
        if (errors.length === 0 ){
            console.log("The entity it's OK")
        }else {
            errors.map(console.log)
        }
    })

Real Example Case

The Alert Schema imported from Fiware Data Models Repository in this Link.

{
    "$schema": "http://json-schema.org/schema#",
    "id": "https://fiware.github.io/dataModels/Alert/schema.json",
    "title": "Alert data model JSON Schema",
    "description": "An alert generated by a user or device in a givel location",
    "type": "object",
    "allOf": [
        {
            "$ref": "https://fiware.github.io/dataModels/common-schema.json#/definitions/GSMA-Commons"
        },
        {

            "$ref": "https://fiware.github.io/dataModels/common-schema.json#/definitions/Location-Commons"

        },
        {
            "properties": {
                "description": {
                    "type": "string"
                },
                "dateObserved": {
                    "type": "string",
                    "format": "date-time"   
                },
                "validFrom": {
                    "type": "string",
                    "format": "date-time"
                },
                "validTo": {
                    "type": "string",
                    "format": "date-time"
                },
                "severity": {
                    "type": "string",
                        "enum": [
                            "informational",
                            "low",
                            "medium",
                            "high",
                            "critical"
                        ]
                },
                "category": {
                    "type": "string",
                    "enum": [
                        "traffic",
                        "weather",
                        "environment",
                        "health",
                        "security"
                    ]
                },
                "subCategory": {
                    "type": "string",
                    "enum": [
                        "trafficJam",
                        "carAccident",
                        "carWrongDirection",
                        "carStopped",
                        "pothole",
                        "roadClosed",
                        "roadWorks",
                        "hazardOnRoad",
                        "injuredBiker",
                        "rainfall",
                        "highTemperature",
                        "lowTemperature",
                        "heatWave",
                        "ice",
                        "snow",
                        "wind",
                        "fog",
                        "flood",
                        "tsunami",
                        "tornado",
                        "tropicalCyclone",
                        "hurricane",
                        "asthmaAttack",
                        "bumpedPatient",
                        "fallenPatient",
                        "heartAttack",
                        "suspiciousAction",
                        "robbery",
                        "assault"
                    ]
            },
            "alertSource": {
                "oneOf": [
                    {
                        "type": "string",
                        "format": "uri"
                    },
                    {
                        "$ref": "https://fiware.github.io/dataModels/common-schema.json#/definitions/EntityIdentifierType"
                    }
                ]
            },
            "data": {
                "type": "object"
            },

                "type": {
                    "type": "string",
                    "enum": [
                        "Alert"
                    ],
                    "description": "NGSI Entity type"
                }
            }
        }
    ],
    "oneOf": [
        {
            "required": [
                "id",
                "type",
                "location",
                "alertSource",
                "category",
                "dateObserved"
            ]
        },
        {
            "required": [
                "id",
                "type",
                "address",
                "alertSource",
                "category",
                "dateObserved"
            ]
        }
    ]
}

var ngsi = require('ngsi-parser');
var ocb = require('ocb-sender');

ngsi.setModel({
    Alert : 'https://raw.githubusercontent.com/smartsdk/dataModels/master/Alert/schema.json'
})

var  alertEntity  = {
    id: "Alert:Device_Smartphone_7a85d9df7209b8bc:1519086635021",
    type: "Alert",
    alertSource: "Device_Smartphone_7a85d9df7209b8bc",
    category: "traffic",
    dateObserved: new  Date(),
    description: "Car Accident on Cenidet",
    location: {
    type : "geo:point",
        value : "18.81186166666667 ,-98.96342000000001"
    },
    severity: "medium",
    subCategory: "carAccident",
    validFrom: new  Date(),
    validTo: new  Date(),
    dateCreated : new  Date()
}

ngsi.verifyModel('Alert', alertEntity, ocb)
.then((errors) => {
    if (errors.length === 0 ){
        console.log("The entity it's OK");
        var ngsiEntity = ngsi.parseEntity(alertEntity);
        ocb.createEntity(ngsiEntity)
        .then((result) => console.log(result))
        .catch((err) => console.log(err))
    }else {
        errors.map(console.log)
        //another action if it does not comply with the model
    }
})