Interacting with Local webpage through Application in real time? - javascript

I want to interact with my local HTML page through my C++ application. Just like using java script console, we can edit a page in real time, e.g
document.getElementById('divlayer').style.visibility = 'hidden';
Similarly i want to call such functions in real time through my application.
Can you give me some idea if there is a way to accomplish this job?
I am using Google Chrome at the moment.
Do i need some plugin, but how can i make plugin to interact with my application then?
Also, i head about JQuery, can this be done using JQuery? Or do i have to try some server mecahnism may be using Ajax??

I know that you can control your IE browser with COM on Windows, and you can interact with the page with it. But I didn't try it with C++, I just use it with Python and it works well. May be you'd like to check it out.

Related

How can I screen scrape a multi page application using javascript?

How can I screen scrape a multi page application? I want to do this using Javascript. Here are the approaches I have considered and the problems I have encountered.
Using the Fetch web API in a Node application to get the web pages
Problem: The web pages won't load properly when being fetched. I guess all javascript on the page does not run when the page is fetched.
Running JavaScript from the console
This is a very simple way to inject JavaScript straight into the document. But one problem is that opening the web page is a browser and pasting into the console is manual work. Another problem is that while this works for single page application it becomes very cumbersome for multi-page applications.
What better approach exists that solves the problems I have encountered?
Depends on what are you doing. If you just want to get some that from some website then injecting JS in the page is the way to go.
But as you said it's manual work from which I deduce you want to scrape the sites and save the data maybe. In this case a service side script is better suited. To fix the problem with the JavaScript not being loaded you can use things like PhantomJs or Horseman.
Take a look at this: https://medium.com/#designman/building-a-performant-web-scraper-in-node-js-5f4449674163
If you want to save website content (html, js, css files, images) to file system you can take a look on website-scraper package for nodejs https://www.npmjs.com/package/website-scraper
It also has plugin for PhantomJS which allows to handle single page applications

How to use Selenium to interact with javascript in python?

First I use python and selenium to load a website in firefox. Then I fill in a simple javascript type form. The site is poorly made but usually if I tell selenium to use (Keys.RETURN) then it will drop down a list of options. The problem is I don't know how to click on one of these because they didn't load with the web page. I tried using (Keys.ARROW_DOWN) to go through them but it still doesn't really work.
How can I interact with javascript through selenium using python?
Thanks.
P.S. I know almost nothing about javascript so if there is some way to do it, I still would be clueless on how to use javascript anyway...
You might have to tell the browser to wait for a few milliseconds.
Some places to look:
Clicking on a Javascript Link on Firefox with Selenium
http://seleniumhq.org/docs/04_webdriver_advanced.jsp

Interacting with webpage from C++ Application

i have a sitation where i want to access HTML DOM object from within my application to update certain parts of web page through javascript commands at run time.
It is a local webpage opened in FireFox which would be accessed by my application, so that the final output is always shown at the webpage which is updated by appliation.
It would be great if you could give me some idea about how this can be accomplished.
I have similar requirement like the webmonkey extension of firefox but need to do it outside of browser from my application.
You can try QtWebKit from the Qt framework, it provides an OO set of classes to interact with webpages from basic actions to very complicated and advanced stuff. I believe you may find your answer there, a link is provided below...
Good Luck
see Here

How can I get dynamically web content using Perl?

This is kind of tricky. There is this webpage which, I am guessing, uses some kind of AJAX to pull out content based on the search query. When I fetch the page using get in Perl, it fetches the script code behind the php/html, but not the results which are displayed when the query is searched manually. I need to be able to fetch the content of the results page. Is there anyway to do this in Perl?
Take a look at Selenium RC and the WWW::Selenium module in Perl. With them you can control a real web browser.
Another option is WWW::HtmlUnit which uses the HtmlUnit Java library to execute the JavaScript without a web browser. WWW::HtmlUnit uses Inline::Java to give Perl access to the library. I have found that when installing, it is best to say No to the question "Do you wish to build the JNI extension?".
If you are writing tests that need to check the rendered page, you can have a look at Schwern's javascript-tap-harness, which works with Selenium and handles all the scaffolding.
I also found Using WWW::Selenium To Test Or Automate An Ajax Website pretty useful.

How to simulate JavaScript in a client C# Applications

I'm writing a web crawler (web spider) that crawl all links in a website.
My application is a Win32 App, written in C# with .Net framework 3.5.
Now I'm using HttpWebRequest an HttpWebResponse to communicate with the web server.
I also built my own Http Parser that can parse anything I want.
I found all link like "href", "src", "action"... in the parse.
But I can not solve one problem: Simulate Client Script in the page (like JS and VBS)
For example, if a link like:
a href = "javascript:buildLink(1)"
... with buildLink(parameter) is a Javascript function that will make a custom link due to the parameter.
Please help me to solve this problem. How to simulate JavaScript in this app? I can parse the HTML source code and take all JavaScript code to another file, but how to simulate a function of it?
Thanks.
Your only real option is to automate a browser. As other answers have said, you cannot reliably simulate browser javascript without having a complete DOM.
There are fortunately ways to automate the browser, check out Selenium.
It has a C# API, so you can control the browser from C#.
Use your .NET web crawler code to crawl the site. Whenever you encounter a href="javascript:... link, handle the page containing the link in Selenium:
Use the Selenium API to tell the browser to load the page.
Use the Selenium API to find all links on the page.
This way, your spider only uses Selenium when necessary (pages without javascript links can be handled by the browser-less spider code you already got). And since this is an embarrassingly parallel workload, you could easily have multiple Selenium processes running at the same time (either on one computer or on other computers).
But remember that href="javascript is hardly the only way a page can have dynamic links. The more common case is probably that a onload or $(document).ready() script manipulates the DOM and adds links that way.
To catch that case (and others), the spider probably will have to use Selenium for all pages that have a <script> tag.
You are basically pretending to be a browser, except that HttpWebRequest only does the networking stuff for you.
I would recommend using the ie web browser control and interop'ing into that from your c# application. That will allow you to run JavaScript, set variables, post, etc etc.
Here's some basic links I found after a search for "ie web browser control":
http://www.c-sharpcorner.com/UploadFile/mahesh/WebBrowserInCSMDB12022005001524AM/WebBrowserInCSMDB.aspx
http://support.microsoft.com/kb/313068
This is a problem which is not easily solved. You could consider taking one of the existing JavaScript implementations and porting or interfacing with it somehow.
If I were tackling this problem, I'd probably build a small side application in Java on top of Rhino, with some sort of RPC framework layered on top of that so that I could communicate with it from my primary application.
Unfortunately, without having a complete DOM implementation on top of that, you would be limited to only very simple javascript.
You could execute the javascript by using the MS JScript engine or something similar.
MSDN Reference
Eric Lippert's blog on using Eval (part 1) (part 2) (part 3)
This isn't guaranteed to work, especially if the javascript tries to access the DOM, or somesuch... But for simple scripts, it might be enough.

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