xml - httr - 不将 xml 解析为文本，但仍指定编码

Question

我正在尝试使用 httr 包抓取以 UTF-8 编码的网站，但显然该content包的功能仅允许在将网站解析为文本时指定编码。不幸的是，我无法将其解析为文本，因为我想在之后对其使用 xpath 查询。这是一个例子：

library(XML)
library(httr)

page <- GET("http://ec.europa.eu/archives/commission_2004-2009/index_en.htm")
test <- content(page, as = "parsed")
# Get a list of names, many of which contain non-standard characters
xpathSApply(test, "//img", xmlGetAttr, "alt") 

# This gives the correct encoding, but outputs a character vector, 
# on which I cannot use xpath queries
test <- content(page, as = "text", encoding = "utf-8")

更新：

# htmlParse returns a parsed document, but the non-standard characters are 
# not properly encoded, i.e. the result is the same whether or not I specify the 
# "encoding" argument
test <- htmlParse(page, encoding = "UTF-8")

# Non-standard characters in names still not properly encoded
xpathSApply(test, "//img", xmlGetAttr, "alt")

Answer 1

尝试：

 test <- htmlParse("http://ec.europa.eu/archives/commission_2004-2009/index_en.htm")
 res <- xpathSApply(test, "//img", xmlGetAttr, "alt")
 tail(res)
 #[1] "Slovakian"   "PDF"         "PDF"         "PDF"         "PDF - 66 KB"
#[6] "français" 

使用您的代码，（第一和第二）

 tail(res1)
 #[1] "Slovakian"   "PDF"         "PDF"         "PDF"         "PDF - 66 KB"
 #[6] "français"  

  tail(res2)
 #[1] "Slovakian"   "PDF"         "PDF"         "PDF"         "PDF - 66 KB"
 #[6] "français"