Lua

REST with Query Params

See more REST Examples

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

local chilkat = require("chilkat")

-- 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".

local rest = chilkat.Rest.new()

-- 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).
local bTls = true
local port = 443
local bAutoReconnect = true
local success = 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.
local responseJson = rest:full_request_no_body("GET", "/search?query=hello%20world&category=books&sortBy=price&filterBy=inStock")
if not rest.last_method_success then
    print(rest.last_error_text)
    return
end

-- 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:clear_all_query_params()
rest:add_query_params("query=hello%20world&category=books&sortBy=price&filterBy=inStock")
responseJson = rest:full_request_no_body("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:clear_all_query_params()
rest:add_query_param("query", "hello world")
rest:add_query_param("category", "books")
rest:add_query_param("sortBy", "price")
rest:add_query_param("filterBy", "inStock")
responseJson = rest:full_request_no_body("GET", "/search")
-- ...
-- ...