How to view webpage source code using R?

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I need to use R to download the source code for a webpage.

When I click on "View source code" in Firefox, I see all of the source code. However, when I use RCurl to download the sourcecode, I only see a part of it. The parts that are missing are produced by Javascript, so maybe that's the problem? Can RCurl not see Javascript-produced information?

How can I get the source code into R? Either through RCurl like I've tried or into a txt file, THEN loaded into R would be fine.

Thanks

elinks text browser has some javascript support. See the docs for how to configure/enhance this support:

elinks -dump www.google.com 

will give you the rendered version of the site.

A better option is to use mozrepl. It connects to firefox and from the command prompt you can do whatever you can do from the webpage javascript:

telnet localhost 4242
repl> var w=window.open("https://google.com")
repl> w.document.getElementsByTagName('html')[0].innerHTML

should give you the page.

The question is how to make this work with R:

mz <- socketConnection("localhost", "4242")
writeLines("var w=window.open(\"https://google.com\")\n",mz)
out <- readLines(mz) #empty the buffer
writeLines("w.document.getElementsByTagName('html')[0].innerHTML\n", mz)
out <- readLines(mz)
str(out)

should give:

 chr [1:73] "repl> repl> \"<head><meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\"><meta itemprop=\"image\" content=\"/"| __truncated__ ...

which you can further filter for what you need.

How to view webpage source code using R?, How to view webpage source code using R? extract data from website using r web scraping with r pdf read webpage in r read local html file in r scrape a  There are different ways to view the source code of an R method or function. It will help to know how the function is working. Internal Functions. If you want to see the source code of the internal function (functions from base packages), just type the name of the function at R prompt such as; > rowMeans.

RCurl just handles the HTTP part of the transfer; it does not have a Javascript interpreter to execute the code in the page (which may download additional HTML or write it directly). You will need to find a command line program which can both download a URL and execute the accompanying Javascript and then save the result to a file. You can call this program using system(), then.

Reading Web Pages with R, To make a copy from inside of R, look at the download.file function. If you look at the web page, you'll see that the title "Opponent / Event" is right above the data we want. We can replace the special characters with the following code: Open Microsoft Edge and navigate to the web page of your choice. Click the More icon in the upper-right corner of the screen. Select Developer Tools from the drop-down menu that appears. Select the Elements tab at the top of the right window.

I have been struggling with exactly the same task for a couple of weeks. I would suggest that the most straightforward way is using rsDriver from the RSelenium library. The RSelenium basics vignette https://cran.r-project.org/web/packages/RSelenium/vignettes/basics.html gives an overview.

 library(RSelenium)

 rD <- rsDriver(verbose = FALSE)

 remDr <- rD$client

 remDr$navigate("http://www.r-project.org")

 XML::htmlParse(remDr$getPageSource()[[1]])

An introduction to web scraping using R, We will see it through the use case of Amazon website from where we will Hadley Wickham authored the rvest package for web scraping in R. Web scraping is the technique of identifying and using these patterns of coding to extract the In this code, we read the HTML content from the given URL, and  I need to use R to download the source code for a webpage. When I click on "View source code" in Firefox, I see all of the source code. However, when I use RCurl to download the sourcecode, I only see a part of it. The parts that are missing are produced by Javascript, so maybe that's the problem? Can RCurl not see Javascript-produced information?

Screen-Scraping in R, Reading a Web-Page into R; Parsing HTML; Parsing with the CSS Selector To view the “source code” of the web page, we can use Chrome's dropdown menu  To view the source code of any webpage on your IOS device, open any site in Safari and select Bookmarks/ ‘View Source’. PRO TIP: here are some awesome free tests to check how good your website is .

Web scraping tutorial in R, Short tutorial on how to create a data set from a web page using R. published a nice tutorial about web scraping using 16 lines of Python code. that we'll be working with, I encourage you to have a look at Kevin's tutorial. an open source tool that makes CSS selector generation and discovery easy. Make it a habit to look through the code, especially the important header tags, such as title, and description. Use our tool to view the formatted version of the source code of any website online. Simply copy the site's URL and paste it above. Then click "View source".

How to view webpage source code using R?, I need to use R to download the source code for a webpage. When I click on "​View source code" in Firefox, I see all of the source code. However, when I use  How do I view source code in R? For example, for function portfolio.optim. > require(tseries) > portfolio.optim function (x, ) UseMethod("portfolio.optim") <environment: namespace:tseries> > methods(portfolio.optim) [1] portfolio.optim.default* portfolio.optim.ts* Non-visible functions are asterisked > portfolio.optim.ts Error: object 'portfolio.optim.ts' not found > portfolio.optim.default Error: object 'portfolio.optim.default' not found.

Comments
  • thanks any suggestions on a command line program that will do that?
  • Sorry, I don't have experience with any program that does that. I thought maybe you could get firefox to do it, but I didn't see anything obvious in my very quick search.