If you create a button using PayPals selling tools you are then presented with auto-generated HTML after filling in the details of the particular product you want to sell. At the bottom of this generated code is this strange piece of HTML:
<img alt="" border="0"
src="https://www.paypalobjects.com/*****-***-******-*/en_GB/i/scr/pixel.gif"
width="1" height="1">
What is this used for? It seems to serve no purpose, in fact, if i delete it, the script still seems to run fine.
I think Tom Gullen is right and the one-pixel image is there for tracking purposes. While trying to answer the same question I found the following article that is probably worth reading: http://en.wikipedia.org/wiki/Web_bug. Especially this part:
"Originally, a web bug was a small (usually 1×1 pixel) transparent GIF or PNG image (or an image of the same color of the background) that was embedded in an HTML page [...] Whenever the user opens the page with a graphical browser or email reader, the image or other information is downloaded. This download requires the browser to request the image from the server storing it, allowing the server to take notice of the download."
It probably is sending data back to Paypal for tracking purposes. I would leave it in, it's highly unlikely to be malicious and might benefit you in the way of tracking stats etc.
It's also utilising an HTTPS connection so any data being sent to the Paypal server is secure.
I'd guess one of two reasons:
In the olden days (2001) we used to use 1px images to make sure borders between objects appeared properly (e.g., in a table). They might do it in case the HTML is embedded on a very outdated web design.
If it includes any kind of ID, they may be using it to gather statistics on how often your button is rendered (perhaps to gauge your click-through rate).
Related
There is a website called file2hd.com which can download any type of content from your website including audio, movies, links, applications, objects and style sheets. Of course this doesn't work for high profile websites such as Google, but is there there a type of method I can use to cloak content on my website and prevent this?
E.g. Using a HTML Code, or using .htaccess method?
Answers are appreciated. :)
If you hide something from the software, you also hide it from regular users. Unless you have a password-protected part of your website. But even then, those users with passwords will be able to fetch all loaded content - HTML is transparent. And since you didn't provide what kind of content are you trying to hide, it's hard to give you a more accurate answer.
One thing you can do, but it works just for certain file types, is to server just small portions of a file. For example, you have a video on your page and you're fetching 5-second bits of the video from the server every 5 seconds. That way, in order for someone to download the whole thing, they'd have to get all the bits (by watching the whole thing) and then find a way to join the parts... and it's usually just not worth it. Think of Google Maps... and Google uses this/similar technique on a few other products as well.
In my web application, a user may make a post with images, embed videos and text with different styles. I want to generate a preview for the post to show it on the front page of the web application. It demands that it doesn't take too much space and as clear as possible.
I know that I need to parse the post html first and may extract image elements first. My consideration for the text is simply to extract all plain texts and show part of them.
Could someone provide other advice, methods or resource about this problem?
As I understand, you want to render a HTML page into an image? You should use some layout engine, such as WebKit or Gecko on server side.
Another option is to use some third-party online tool for these previews. But rendering the page is pretty hard process, because of it's time complexity and memory space requirements for storing images. I have found these services:
http://www.thumboo.com/
http://www.thumbalizr.com/
http://www.zubrag.com/scripts/website-thumbnail-generator.php
Part of my job involves turning psd designs into html to be emailed out for email campaigns. In the past I've always gone through and converted everything to a suitable html element where possible but I'm now questioning whether there's any point to it?
Is okay just to use one giant image? I only ask because it seems using html elements is only really important if a) I want the information in the email to get to the client if images are blocked and b) for SEO.. yet search engines won't be indexing my code since it's all going through email.
If I'm pretty confident that the clients I'll be mailing won't have the images blocked, is it okay just to treat the entire email body as an <img />?
Thanks
I guess it would be okay, but I wouldn't recommend it. Here are a few reasons why:
The readers won't be able to select and copy any of the content in the email, which in my opinion is really annoying.
You will not be able to have links in your email, the only thing you can link is the entire image.
If they do have images disabled, which i believe is fairly common, the wouldn't see a thing without downloading the image.
Increased email size due to the large image, which for mobile devices is a pain.
An image will not adapt to the window/display size. Text/HTML-based mails can at least break row if the content doesn't fit, to make it more readable.
And the list goes on. The other answers point out a number of additional reasons as well.
I don’t know that there is any definitive answer to this question, but here is my take on it:
I think it’s a good idea to convert certain elements to text so that they can be copied or manipulated. If you have a phone number, you may want that to be readable so that anyone with an automated dialer can click and complete the call. Certain email programs might automatically convert an address to a link to the map. Those features won’t work if any of these elements are flattened into the jpg.
For those mobile email clients that will not render the image on the screen (either because it’s just showing the preview or hasn’t yet downloaded the content) it’s useful to see some of the alternate text (and body content) before viewing the full image.
I know you said that you are sure your clients won’t have images blocked, but you can’t really rely on that. A well-meaning administrator who makes a change to the firewall could accidentally block all incoming images to the entire domain and your email will be worthless.
Lastly, an HTML email with one line of code to load an image has a high possibility of being flagged as spam.
I hope this helps!
What about bandwidth concerns, for users viewing your email on a mobile device? If it's a large image, do you want to blow out their data caps?
Or users using assistive technology, for visually-impaired people. Such as a screenreader(text to speech).The real text is helpful for scenarios like that.
I'm trying to do some HTML layouts, and pretty much my problem comes in here:
<img src = "https://something.com/image.png">
The image can be displayed in a browser when navigating to the URL, but not in Microsoft Visual Studio (or the browser when loading this HTML page), it displays as a broken image instead. This leads me to believe it cannot be linked to in such a way (as I can view other images this way). I'm wondering if it has anything to do with it requiring a secure http connection and if there's any way around this.
Basically, the picture comes up when the url is navigated to. However, when opening this HTML file that has the image displayed on it, it comes up as a broken image. I'm wondering why this is.
Thanks.
You 'll need to establish a secure connection to do that. When the browser comes across the url you have placed as src of the image it sends out a request to that server, which responds by offering different encryption methods it supports. But since you 'll be browsing the page as http data you won't be able to understand the response (which is supposed to be image data if the other side is http and now happens to be a query for encryption method). In short you are missing an SSL layer to make your communication sensible and therefore you see a broken image.
Try making it a background image in your css.
edit I am getting down voted for this question. I should have prefaced that I am not sure and was taking a wild guess, if anything to offer an idea that was not presented by the asker to help solve the problem :)
I am thinking to create an website that generates HTML through a wizard.Finally, I want to make the users to buy the generated HTML source if they like what they see.
But I don't want to let the users to steal the HTML, CSS and JS that I use to create the effect they want.
I want a technique which is immune to Firebug and Right Click -> View Page Source.
Any thoughts ?
edit: I remember something about iframes or frameset, but I'm not sure how to fool the browser and Firebug to execute the code without updating their capability of showing that source code. A popup is also a possible solution.
edit 2: html hosted in silverlight ? will you use it ?
The best thing you can do is to just obfuscate your code. Trying to hide the source is not going to work (for ex: if you disable right click-> view source that doesn't stop them from using the menu or saving the page or using a shortcut key or writing an app to stream the http request into a file and open that, etc).
Firstly, depending on what you are doing you can have the HTML code loaded through JS after the page load (AJAX).
As far as your JS goes:
Free Obfuscator
Not Free Obfuscator
In the end though, there is no stopping someone who really wants to get that source. Even obfuscated code can be rebuilt (though it's hell on wheels painful depending on how good the obfuscator is).
To really protect the sample HTML from prying eyes, you'd need to render it on the server-side and only pass image data to the client. If you want the user to be able to interact with the sample as if it were a normal Web page, you'll also need to send their pointer and keyboard inputs to the server and update the displayed image when necessary. At that point, though, you're basically making an HTTP-based version of VNC. This is definitely possible, but I don't think it will be easy, and I doubt there are any existing software packages to let you do this. If I were you, I'd rethink my business model a bit.
Sending XSL-templated XML to the browser may be enough fool some, and it will work more or less the same in many modern browsers including IE6 (maybe even 5.5).
But really, trying to hide the HTML code isn't going to work if anyone halfway serious wants to get it.
I am thinking to create an website that generates HTML through a wizard.
Finally, I want to make the users to buy the generated HTML source if they like what they see.
If this is what you need you might consider the possibility of creating a preview of the page as an image, and provide the download of the source only after the user agreed and paid. There is no magic way to let a browser display a code that you can't see.
You can make a video, showing the functionality and upload the same, which may help users to view / feel it.