conduit中的HTTP查询参数

conduit中的HTTP查询参数

本文介绍了处理http-conduit中的HTTP查询参数的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我想下载网址的内容

  http://example.com/foobar?key1=value1& key2 = value2 

使用(GET请求)。

我该怎么做:
$ b $ a)假设我已经知道完整的(即编码的URL)
b)如果一些参数是动态的,因此不是URL编码的? b
$ b

注意:这个问题被回答为Q& A式,因此故意没有显示任何研究工作。

解决方案

关于a):

您可以使用 simpleHttp 与一个包含查询参数的URL,就像文档中的示例一样:
$ b

  { - #LANGUAGE OverloadedStrings# - } 
导入Network.HTTP.Conduit
将合格的Data.ByteString.Lazy导入为LB

mai n :: IO()
main =
simpleHttphttp://example.com/foobar?key1=value1&key2=value2>> = LB.putStr
code>

关于b):

您需要一个键/值列表包含您的查询参数的 [(ByteString,Maybe ByteString)] 类型的元组。

导入合格的Data.ByteString。 Lazy.Char8作为LB 

queryParams :: [(ByteString,也许ByteString)]
queryParams = [
(key1,只是value1),
(key2,只是value2)]

main :: IO()
main = do
请求< - parseUrlhttp://example.com/ foob​​ar
let request= setQueryString queryParams请求
响应< - withManager $ httpLbs请求'
LB.putStrLn $ responseBody响应

注意:这至少需要 http-conduit 2.1。
另请注意,建议在适用的情况下重复使用 Manager 实例。


I want to download the content of the URL

http://example.com/foobar?key1=value1&key2=value2

using http-conduit (GET request).

How can I do that:

a) Assuming I already know the full (i.e. encoded URL)b) If some parameters are dynamic and therefore not URL-encoded?

Note: This question was answered Q&A-style and therefore intentionally does not show any research effort.

解决方案

Regarding a):

You can use simpleHttp with an URL containing query parameters just like the example in the docs:

{-# LANGUAGE OverloadedStrings #-}
import Network.HTTP.Conduit
import qualified Data.ByteString.Lazy as LB

main :: IO ()
main =
    simpleHttp "http://example.com/foobar?key1=value1&key2=value2" >>= LB.putStr

Regarding b):

You need a list of key/value tuples of type [(ByteString, Maybe ByteString)] that contains your query parameters.

{-# LANGUAGE OverloadedStrings #-}
import Network.HTTP.Conduit
import Data.ByteString (ByteString)
import qualified Data.ByteString.Lazy.Char8 as LB

queryParams :: [(ByteString, Maybe ByteString)]
queryParams = [
    ("key1", Just "value1"),
    ("key2", Just "value2")]

main :: IO ()
main = do
    request <- parseUrl "http://example.com/foobar"
    let request' = setQueryString queryParams request
    response <- withManager $ httpLbs request'
    LB.putStrLn $ responseBody response

Note: This requires at least http-conduit 2.1.Also note that it is recommended to reuse Manager instances where applicable.

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08-06 00:45