Dart

REST with Query Params

See more REST Examples

Demonstrates how to add query params for a REST request. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // Let's say we want to send a GET request to 
  // https://example.com/search?query=hello%20world&category=books&sortBy=price&filterBy=inStock

  // Notice that the query parameter values must be URL encoded.

  // Let's also explain the parts of the above URL:

  //     Scheme: https
  //         The scheme specifies the protocol used to access the resource. 
  //         In this case, it is "https," which indicates that the resource is accessed using the Hypertext Transfer Protocol Secure (HTTPS).
  // 
  //     Host: example.com
  //         The host part of the URL identifies the domain name or IP address of the server hosting the resource. In this case, "example.com" is the host.
  // 
  //     Path: /search
  //         The path is the specific location or resource on the server that the client wants to access. 
  //         In this URL, the path is "/search," indicating that the client is requesting the "search" resource on the server.
  // 
  //     Query Parameters:
  //         Query parameters are used to send additional data to the server as key-value pairs. 
  //         They are separated from the path by a question mark ? and each parameter is separated by an ampersand &.
  // 
  //         The above URL has four query parameters:
  //             query=hello%20world: The "query" parameter with the value "hello world". The %20 represents the URL-encoded space character in the value.
  //             category=books: The "category" parameter with the value "books".
  //             sortBy=price: The "sortBy" parameter with the value "price".
  //             filterBy=inStock: The "filterBy" parameter with the value "inStock".

  final rest = CkRest();

  // Connect to the REST server.

  // The Host part of the URL is passed in the 1st argument.
  // The Scheme part of the URL ("https") is indicated by the 2nd and 3rd arguments (port and bTls).
  final bTls = true;
  final port = 443;
  final bAutoReconnect = true;
  rest.connect('example.com', port, bTls, bAutoReconnect);

  // There are 3 ways to send the above GET request.

  // 1) Send the request with path and query params pre-built, where the query param values are URL encoded.
  String responseJson;
  try {
    responseJson = rest.fullRequestNoBody('GET', '/search?query=hello%20world&category=books&sortBy=price&filterBy=inStock');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // 2) Pass only the Path part of the URL, and specify the query params separately by calling AddQueryParams beforehand.
  //    Again, the query params must be already URL encoded when passed to AddQueryParams
  rest.clearAllQueryParams();
  rest.addQueryParams('query=hello%20world&category=books&sortBy=price&filterBy=inStock');
  responseJson = rest.fullRequestNoBody('GET', '/search');
  // ...
  // ...

  // 3) Pass each query parameter separately by calling AddQueryParam.  In this case, the query param value should be passed without URL encoding.
  //    (ClearAllQueryParams ensures any params set for previous request are cleared.)
  rest.clearAllQueryParams();
  rest.addQueryParam('query', 'hello world');
  rest.addQueryParam('category', 'books');
  rest.addQueryParam('sortBy', 'price');
  rest.addQueryParam('filterBy', 'inStock');
  responseJson = rest.fullRequestNoBody('GET', '/search');
  // ...
  // ...
}