jsend 1.0.14

Implementation of jsend specification in dart.

Implementation of jsend specification in dart. Simply putting, jsend is a specification that tells how JSON responses coming from server should be structured.

Using

import 'package:jsend/jsend.dart';

// ... some code

var someHTTPResponse = await http.get('https://api-that-gives-json-response');

// obtained HTTP Response can be parsed to jsend Response as

var jsendResp = jsendResponse(someHTTPResponse);

// Even Easier Now. jsendResponse object can be created from APIRequest object as:

APIRequest.base = 'https://jsonplaceholder.typicode.com/';
jsendResponse.fromAPIRequest(APIRequest(
    path: '/users'
)) ;

Getting status, message and data

//status
jsendResp.status

//message
jsendResp.message

//data
jsendResp.data

Handling validation errors in fields

By jsend standard, we send validation errors in data field. This package contains some helper methods to read errors in fields.

//checking if errors exist in a field

if(jsendResp.hasErrorIn('email')){
    // executed if errors exist in email field
}

//getting errors in a field
var errorInEmail = jsendResp.errorIn('email') ;
// returns null in case no errors exist.

Status Handlers

Status handling can be done in declarative programming style. Since we are lazy and dont like this type of code:

...

if(jsendResp.status == 'success'){
    // do something
}else if(jsendResp.status == 'error'){
    // do another thing
}else {
    // do some other thing
}

...

This package helps us by assigning the status handlers in constructor of jsendResponse as:

...
jsendResponse.fromAPIRequest(APIRequest(
        path: '/users'
    ),
    onSuccess: (jsendResponse resp){
        print('Fetched Successfully') ;
        print(resp.data) ;
    },
    onError: (_){
        print("failed") ;
    }
) ;

RemoteResource class might surprise you

See how easily I perform CRUD operations on data on server.

//setting API Base first
APIRequset.base = 'http://your-server/api/' ;

//Creating RemoteResource instance that fetches from /products
var productsFetcher = RemoteResource('products') ;

Showing all products

//mapped to GET /products
print(await productsFetcher.getAll()) ;

Getting single product

//mapped to GET /prdoucts/:product_id
print(await productsFetcher.get("prdouct_id")) ;

Creating new product

//mapped to POST /products
await productsFetcher.createItem({name: 'Apple', price: 34}) ;

Worried about handling validation Errors from server ? You can easily handle them as:

await productsFetcher.createItem({...}, statusHandlers: [JsendStatusHandler(
    forError: (jsendResponse resp){...},
    forSuccess: (jsendResponse resp){...},
    forFail: (jsendResponse resp){
        if(resp.hasErrorIn('name')){
            print('Response contains error in name: ' + resp.errorIn('name')) ;
        }
    }
)])

statusHandlers can be applied to all methods of RemoteResource

Updating Product

// mapped to PUT /products/:product_id
await productsFetcher.updateItem({_id: 'id', ...});

Deleting Product

//mapped to DELETE /products/:product_id
await productsFetcher.deleteItem({_id: 'id',...}, statusHandlers: [JsendStatusHandler(
    forSuccess: (_){
        print("Deleted Successfully.") ;
    }
)]);