I use Java. I want to get web page source code but on the page works JavaScript and I want get code generated by JavaScript (code which we see in firebug in firefox)
Anyone knows what I should do?
To inspect the page after modification by JavaScript, you need a client-side JavaScript engine that can run the scripts and then let you inspect the DOM.
HtmlUnit can do this - it is a "GUI-Less browser for Java programs".
See also this question
However, this won't give you the exact original page source, because that has already been parsed into a DOM by this point.
I think you want to see the source code of DOM Elements created after the page load via AJAX.
If that´s what you want, the only way to see it is through a DOM inspector, like firebug in firefox or Developers Tools in Chrome.
Going to "View source code" only shows the source at load-time.
If I understand your question, yes your javascript objects can be passed back to your java backend either by a creating a html <form> element with inputelements, fill them with your values and then submit the form, or asynchronously via ajax/json (which doesn't require re-loading your web page). For both methods you need to configure an endpoint on your java side to receive the submitted data and return some kind of confirmation to the client, i.e. your javascript. I would recommend googling "jQuery.post" for the javascript side and finding some examples for your java backend.
Related
I'm trying to use Jsoup to gather wave height information from Surfline.com. I have the element I desire in the screenshot and the it's showing in the dev tools. When I scrape the site with Jsoup, the returned string includes everything seen in the dev tool but the "1-2ft" which is what I need. The site is Javascript heavy and I'm assuming that jsoup is snagging the html before the javascript actually runs (I have no clue really). Do I need to specifically tell jsoup to wait for the pageload or am I missing some other critical component?
This is the code I'm using.
Document doc = Jsoup.connect("http://www.surfline.com/surf-report/folly-beach-pier-southside-southeast_5294/").get();
Elements content = doc.select("div[id=current-surf-range]");
System.out.println(content);
and this is the output I'm seeing in my IDE
<div id="current-surf-range" style="font-size:21px;font-weight:bold;padding-top:7px; padding-bottom: 7px;"></div>
it seems really odd that the contents of the div wouldn't be returned with it. This is my first time using Jsoup and I tried to read through the docs as best I could but nothing seemed to touch on this particular issue. Any insight would be awesome and greatly appreciated.
What you see in the browser is not what necessarily you would get when download the page by URL with your HTTP library of a choice. In fact, you should never expect them to be the same. In the modern web, webpages are quite dynamic and are loaded asynchronously involving multiple API calls to different resource providers and javascript being executed in the browser (which has the javascript engine).
What you get with JSoup in this case is the initial HTML that browser starts to form the page with. Then, there is a set of XHR calls to the surfline API that brings the data into the browser which then dynamically fills up different parts of the page, including the current surf range.
The simplest way to approach the problem is to switch to browser automation tool called selenium which would fire up a real browser. You can then wait for the current surf range element to have a value and, if you wish to continue with JSoup, get the page source and feed it to JSoup for further parsing.
Another approach would involve looking into the requests that the page makes in the browser developer tools and then try to simulate these requests in your code, parsing the JSON responses and extracting the surf forecast data.
I have been writing c#, html, js, jquery for awhile and been using F12 in chrome and IE to look at the html code to help me with some dom manipulation. I am curious if there is a way to do something similar to that context to look at a jsp page and manipulate it with javascript.
For example: viewsource on a jsp page and fill out a textbox on the jsp page with javascript.
I hope the question is clear and the example makes sense. I am not working on anything with this so I don't have a real example. This is more of curiosity. I know javascript but I am not familiar with java at all.
The jsp file gets compiled to a servlet on the Application Server which is then executed. This servlet then produces html on the server side, therefore you can not view the jsp source code client side (F12 in chrome). You can only view the generated output (html, css, js, ...).
Source: http://oreilly.com/catalog/jserverpages2/chapter/ch03.html
JSP is compiled and run on the server side--the same place you edit it (more or less).
Only HTML is sent to the client.
In addition,
You write in C#, so if you generate simple ASP.NET page and see how a dynamic page is being generated.
It's not JSP/Java but It have the same concept of dynamic pages.
in my project I need to read some web pages. Usually it is pretty easy: I read the source code using java classes, parse the output and save interesting data.
But sometimes it is harder; for example reading Google pages. I think it is because of javascript. Do you know to get the real web page code, I mean without javascript? For example if I analyse the page using the Firebug extension of Firefox I read exactly what I need: javascript is correctly replaced by its results. Any idea to do it using Java?
Thanks in advance
I need to convert a web page [which has not public access] to PDF or Image [preferably to PNG].
Web page contains set of charts and image. Most of the charts are populated through Ajax calls so there is a delay between page load and chart load.
I am looking answer for any of these questions:
1- I found set of snapshot api's but none of them support accessing my internal page. Since the web page I am trying to export is not public I need to be authenticated. Biggest problem is I cannot send request headers [such as session-id, cookie or other variables] along with these API's. It seems they don't support this kind of functionality.
2- I am not sure if I can do following: Login to my web page with HTTP client, add http headers, send get call and get HTML string. Then use one of the converters to convert it to PDF. What I am not sure is if it's possible to get proper PDF from the HTML string I got from http client since resources [css, js and etc] will be missing. I want my pdf/image looks exactly as it on the web site.
I really appreciate if you can help.
Thanks in advance,
ED
You're probably best of using wkhtmltopdf, which is a server-side tool and is easily installed.
There are two parameters you can use to wait for your Ajax to finish, try:
javascript-delay to influence the time the program waits for the JavaScript to finish
window-status to wait for a certain return code for the window
See the extensive manual for this program here
wkhtmltopdf generates a PDF and wkhtmltoimg generates an image, which is PNG (as you requested) by default.
Authentication is difficult because it involves security. Because the operation you are describing is unusual it is likely to result in all kinds of alarm bells going off. It is entirely possible to do but it is fraught, easy to get wrong and fragile in the face of security updates and code changes.
As such I'm going to suggest an alternate method which is one we often recommend for ABCpdf (on which I work). Yes we support standard authentication methods but the beauty of this approach is that it is robust and is applicable to other solutions (eg Java based) and novel authentication methods.
Typically you just want a PDF of the current page. The easiest way to do this is snaffle the HTML. The way you do this rather depends on your environment. For example under ASP.NET you can obtain the HTML of the current page using the HttpResponse.Filter property or by overriding the Render method of the page. The way you do it will depend on what you're coding in.
Then you need to save this HTML to a file and present it to your solution via a 'file://' protocol URL. Now obviously at this point any relative links will be broken but this is easily fixed by dropping in a BASE tag that references the place they are located.
Generally the types of resources referenced by an server-side page are static. So if you can create a tag that references the actual files rather than a web site, you will bypass any authentication for access to these resources.
That still leaves the AJAX based problems which are another can of worms. The render delay method is something we have supported for many years (from before AJAX was around) however it is not terribly reliable because you just don't know how long to wait.
Much better is a tighter link into the JavaScript via a callback you can use to determine if the page is loaded. I don't think ABCpdf is going to be appropriate for you since it is .NET but I would certainly encourage you to look for a Java based solution that uses this type of more sophisticated approach.
I need a solution for getting HTML content from a browser. As rendering in a browser, js will be ran, and if not, js won't be ran. So any html libraries like lxml, beautifulsoup and others are all not gonna work.
I've searched a project named pywebkitgtk, but it's purpose is to create a browser with a front end.
Is there any way to put a url into a "fake browser" and render it and run its all javascript and save it into a html file? I don't need any front-end, just back-end is ok.
I need to use Python or java to do that.
selenium-rc lets you drive an actual browser for your purpose, under control of any of several languages at your choice, which include both Python and Java. Check it out!
For a detailed example of use with Python, see here.