使用查询参数呈现网址 [英] Render url with query parameters
问题描述
找不到简单问题的解决方案，答案应该很明显.如何在哈姆雷特模板中使用查询参数呈现网址?
Can't find solution to a simple problem, the answer should be obvious. How to render url with a query parameters inside hamlet template?
即@{ItemsR}将生成http://localhost:3000/items，我该如何生成类似http://localhost:3000/items?page=10&sort=name的内容?
I.e. @{ItemsR} will generate http://localhost:3000/items and how do I generate something like http://localhost:3000/items?page=10&sort=name?
推荐答案
Yesod是RESTful的，如果希望使用QueryString格式，则应使用url格式的参数(例如/items/page/10/sortby/name)，然后丢失Yesod类型安全的网址管理.
Yesod is RESTful, you should use arguments in url format (eg. /items/page/10/sortby/name) if you wish use QueryString format then, you loss the Yesod type safe url management.
下面的示例演示如何使用不同的RESTful表示形式和重定向(从查询字符串中读取参数)到请求的重定向(呈现查询字符串url)
Below example show how use different RESTful representation and a redirection (rendering a querystring url) to a request reading arguments from querystring
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE MultiParamTypeClasses #-}
import Yesod
import Data.Text
import Network.Wai.Handler.Warp (run)
data RouteTest = RouteTest
mkYesod "RouteTest" [parseRoutes|
/item/all/page/#Int/sortby/#Text Items1R GET
/items/page/#Int/sortby/#Text Items2R GET
/items/#Int/#Text Items3R GET
/itemsquery ItemsQueryR GET
|]
instance Yesod RouteTest where
defaultLayout widget = do
pc <- widgetToPageContent widget
hamletToRepHtml [hamlet|\<!DOCTYPE html><html lang="en"><body>^{pageBody pc}</body></html>|]
getItemsR :: Text -> Int -> Text -> HandlerT RouteTest IO Html
getItemsR path page sortby =
defaultLayout [whamlet|
<h1>Items Page ##{page} sorted by #{sortby}
<h4>(Using #{path} path format)
<p>Same request in query string format
<a href="@{ItemsQueryR}?page=#{page}&sort=#{sortby}">
here
|]
getItems1R = getItemsR $ pack "large"
getItems2R = getItemsR $ pack "medium"
getItems3R = getItemsR $ pack "short"
getItemsQueryR = do
req <- getRequest
defaultLayout [whamlet|
<h1>Query String arguments format
<ul>
$forall (k, v) <- reqGetParams req
<li>
<b>#{k}</b>: #{v}
|]
main = run 8181 =<< toWaiApp RouteTest
当然，您可以编写一个帮助程序来接受像您的@{ItemsR page sortby}
of course, you can write a helper to take some like your @{ItemsR page sortby}
renderItemsQueryR page sortby = hamletToRepHtml [hamlet|@{ItemsQueryR}?page=#{page}&sort=#{sortby}|]
但您必须使用
...
url <- renderItemsQueryR page sortby
defaultLayout [whamlet|
...
<a href=#{url}>
...
|]
最后，您可以编写其他助手来呈现任何查询字符串url
finally, you can write other helper to render any querystring url
renderQueryString path keyValues = do
let querystring = intercalate "&" $ map (\(k, v) -> concat [k, "=", v]) keyValues
hamletToRepHtml [hamlet|@{path}?#{querystring}|]
然后，renderItemsQueryR可以写为
renderItemsQueryR page sortby = renderQueryString ItemsQueryR [("page" , show page)
,("sortby", sortby )]
这篇关于使用查询参数呈现网址的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
