Image Surfer Pro User Manual

Missing Or Broken Media Files

Image Surfer Pro supports three different types of media files. Each of these media types is treated a specific way by Image Surfer Pro and displayed in the visualization files accordingly. Knowing how these media files are handled and presented by Image Surfer Pro can be important.

Image Files

Image files are always displayed in visualization pages using the <img> HTML construct. On guide pages, images will link to additional Image Surfer Pro visualization pages. On detail pages, each image will provide a direct link to the original URL used to display the image. As long as the URL resolves to an actual location on a hosting server, data will be provided back to IE from the hosting server. IE will attempt to match the data provided to known image file formats. If the data provided can not be interpreted as one of the known image formats it will be discarded and a Missing Image Block will be shown on the visualization page instead.

Screen capture of a IE display of missing or non image file with file name visible

It may be impossible to know if the file was actually missing or just not in a known IE image format without directly accessing the URL. Accessing a URL in this manner is quite safe because no matter what data stream is sent to IE, if it can not be displayed as an image, it is discarded. However, you should be careful of clicking on one of these Missing Image Blocks because the hyper-link to the original URL will directly access the same data stream without the context of it being an image when the data stream is provided to IE - which may compromise your browser data.

Video Files

Video files are always displayed in visualization pages using the <video> HTML construct. On guide pages, the poster image will link to additional Image Surfer Pro visualization pages. On detail pages, each video will provide an interactive video element created by IE. As long as the URL resolves to an actual location on a hosting server, data will be provided back to IE from the hosting server. IE will attempt to match the data provided to the MP4 video file format. If the data provided can not be interpreted as an MP4 file, it will be discarded and a Missing Video Block will be shown on the visualization page instead.

Screen capture of a IE display of missing or non video file It may be impossible to know if the file was actually missing or just not in the MP4 format without directly accessing the URL. Accessing a URL in this manner is quite safe because no matter what data stream is sent to IE, if it not in the MP4 file format, it is discarded. Interacting with a Missing Video Block is of no consequence because you are interacting with IE not the end server.

Frames

Technically frames are not file references but rather a data stream connection to a hosting server. Because of this, frames are inherently risky. The format of the data received is not tied to a specific file format and interacting with a frame is close to directly interacting with the hosting server. Frame links are always displayed in visualization pages using the <iframe> HTML construct. On guide pages, a text description will link to additional Image Surfer Pro visualization pages. On detail pages, each frame will provide an interactive window created by IE but connected to the hosting server. Virtually any type of hosted data stream can be displayed in a frame. The frame is essentially a smaller browser window and you should exercise the same caution when interacting with content in a frame as you would if the contents of that frame were displayed in the full browser window.

If the URL does not resolve to a valid hosting location it is the hosting server which provides the resulting error stream and not IE. Because of this, we can not accurately say what will be displayed by an incorrect Frame reference.

Screen capture of a IE display of missing or invalid frame reference Some responses we have seen include this Missing Frame Block which seems to indicate the associated video is missing. We have also seen other responses - including the substitution of a "similar" video into the frame. It is important to realize, that no matter what shows up in the frame, interacting with the small window is interacting with the hosting server and not directly with IE.

Page References

The page is intended to be the catch all data type for Image Surfer Pro. It takes advantage of the same <iframe> construct as a Frame which allows it to display basically anything IE can render. Though it can be used to display any URL, it should be used only to collect links which are not one of the other three data types.

Because Pages are displayed using the same <iframe> HTML construct as a frame - they are subject to the same errors as a frame and may display in much the same way if the intended source of the Page reference was a video. However, if you are following the Best Practices guidelines in building your fusker collections, the more common case it the display of the 404 File Not Found reference page for the hosting domain. Often this is simply another webpage letting you know the desired content was not found and providing some helpful links on where content can be found on the hosted domain.

Screen capture of a IE display of a blocked frame reference to a URL In some cases for both Frame and Page references, the hosting site has specifically blocked the display of their content in a frame external to their own domain. This is the case for YouTube so do not be surprised if you see this notification in the display of a Page reference.

What To Do With Broken Links

Whether or not you purposefully added a file to your fusker collection you are likely to encounter situations where references in your fusker collection are invalid or not the right data type. This can happen for many different reasons, but here are a few common instances which can cause this to happen:

In all of these cases you will see something similar to the missing file blocks described above. While missing files are of little consequence in viewing the fusker collection they should be avoided because even accidently clicking the link could expose you to harmful or undesired content (except for missing video files). In addition each missing file reference causes a hosting server error event which initiates tracking. In some cases your IP address may be temporarily or permanently blocked from accessing the domain. Therefore it is in your best interest to try and not generate missing file references and to eliminate any from fusker collections you utilize.

Utilizing the Image Surfer Pro Forms or automated page processing capabilities of Image Surfer Pro will help keep you from creating references to missing files as both techniques reference only files which are known to exist (or were at least referenced by other hosted pages).

Obviously changing the start or end values of a numerical fusk will remove references to missing files at the beginning or end of the sequence easily enough. A simple use of Image Surfer Pro Forms can be used to remove missing file references in the middle of any fusk:

Using this technique will convert a numerically fusked file definition to a list fusked file which does not contain the references to the missing files.

Screen Capture Examples

Screen capture of the examples page

A detailed example utilizing Auto Ranging, Image Surfer Pro Forms, Auto Range Override, and several techniques for working with a real world webpage to first build a fusker collection with missing file blocks and then remove them. The example can be read or you can duplicate the configuraitons and perform the exact operations yourself for deeper understanding.