在rvest中使用submit_form

Question

我試圖抓取一個網站的數據。以下是我正在使用的腳本的簡化版本。在這個例子中disease.table通過html_table在最後一行retreived應該包括所有的從年2014年2017年。目前，它僅包含2017年

# Initiate wahis.session website session. 
url <- "http://www.oie.int/wahis_2/public/wahid.php/Diseaseinformation/statusdetail" 
wahis.session <- html_session(url) 

# Get forms with searchable fields in current session. 
form <- html_form(wahis.session) 

#------------------------------------------------------------------------------ 
# Fill out and submit forms 

# First, Copy form. 
filled.form <- form 

# Set values in form #3 
filled.form[[3]] <- set_values(filled.form[[3]], 
           selected_start_year = "2014") # start year 
# Set form url to empty character string to prevent error message when 
# submitting. 
filled.form[[3]]$url <- "" 

# Submit form #3 
submit_form(session = wahis.session, 
     form = filled.form[[3]], 
     submit = 'disease_id_terrestrial') 

#------------------------------------------------------------------------------ 
# Retreive data 

# Find data table 
disease.table <- wahis.session %>% 
    html_node("div.OverflowAutoScroll table.TableFoyers") %>% 
    html_table(fill = TRUE) 

Answer 1

我找到了答案。 submit_form()函數需要應用於活動的html會話。使用以下代碼提交表單：

# Submit form #3 
wahis.session <- submit_form(session = wahis.session, 
     form = filled.form[[3]], 
     submit = 'disease_id_terrestrial' 

無需其他更改。