rvest 抓取 html 内容值

Question

I'm trying to scrape the following page: link in order to create a data frame with 6 columns: position, company and meta (1-5). Unfortunately I don't know how to catch the values in content for example <meta itemprop="jobLocation" content="Tauragė" /> so the value Tauragė would be used in creating my dataframe (in this example).

My initial code:

if(!require("tidyverse")) install.packages("tidyverse"); library("tidyverse")
if(!require("rvest")) install.packages("rvest"); library("rvest")

# setting url and reading html code 
url <- "https://www.cv.lt/employee/announcementsAll.do?regular=true&salaryInterval=-1&interval=2&ipp=1000"
html <- read_html(url, encoding = "utf-8")

# creating a dataframe of ads
ads <- html %>%{
  data.frame(
    position=html_nodes(html, "tbody p a:nth-child(1)") %>% html_text(),
    company=html_nodes(html, "tbody p a:nth-child(2)")%>% html_text(),
    meta1=...
    meta2=...
    meta3=...
    meta4=...
    meta5=... 
)}

an example of html code:

<td>
    <p itemscope itemtype="http://schema.org/JobPosting">
        <a href="/valstybes-tarnyba/vsi-taurages-rajono-pirmines-sveikatos-prieziuros-centro-direktorius-taurageje-2-338912727/?sri=83" target="_blank" itemprop="title" onclick="$(this).parents('tr.data').addClass('read');">VšĮ Tauragės rajono pirminės sveikatos priežiūros centro direktorius</a>
        <a href="/viesoji-istaiga-taurages-rajono-pirmines-sveikatos-prieziuros-centras-darbo-skelbimai" target="_blank" itemprop="hiringOrganization" itemscope itemtype="http://schema.org/Organization"><span itemprop="name">Viešoji įstaiga Tauragės rajono pirminės sveikatos priežiūros centras</span></a>
        <meta itemprop="jobLocation" content="Tauragė" />
        <meta itemprop="datePosted" content="2019-08-22" />
        <meta itemprop="employmentType" content="FULL_TIME" />
        <meta itemprop="validThrough" content="2019-09-06T00:00:00.000" />
        <meta itemprop="url" content="https://www.cv.lt/valstybes-tarnyba/vsi-taurages-rajono-pirmines-sveikatos-prieziuros-centro-direktorius-taurageje-2-338912727" />
    </p>
</td>
<td>

Answer 1

You can run this,

my_content <- html %>% html_nodes("tbody p meta")  %>%  html_attr("content") 

After that, by indexing each of them, you can split them into meta1, meta2,...meta5 like,

index <- rep(1:5,101)
meta <- data.frame(Meta= my_content,Index=index)

meta1 <- meta[meta$Index==1,]
meta2 <- meta[meta$Index==2,]
meta3 <- meta[meta$Index==3,]
meta4 <- meta[meta$Index==4,]
meta5 <- meta[meta$Index==5,]      

EDIT :

Another approach is using the itemprop values inside html_nodes()

html %>% html_nodes("[itemprop='jobLocation']") %>% html_attr("content") 

gives only the Meta1 for you. If you use the itemprop values for each Meta , you can take the data inside them like,

 meta1 <-    html %>% html_nodes("[itemprop='jobLocation']") %>% html_attr("content") 
 meta2 <-    html %>% html_nodes("[itemprop='datePosted']") %>% html_attr("content") 
 meta3 <-    html %>% html_nodes("[itemprop='employmentType']") %>% html_attr("content") 
 meta4 <-    html %>% html_nodes("[itemprop='validThrough']") %>% html_attr("content") 
 meta5 <-    html %>% html_nodes("[itemprop='url']") %>% html_attr("content")