jQuery Printed Footer Links
Monday, March 8. 2010
I was randomly perusing the web and stumbled across an older interesting List Apart article (September 19, 2005 to be exact). In it, the author used JavaScript to create a list of all links found on the page, and then create a footer with a footnote-like list. I was using simple CSS to display the URL of the hyperlink in print display media, but that doesn't work in some browsers (IE), and worse off it can really mess up the visual order of the page.
Inspired by the article's intentions, I decided to use some jQuery to whip up a similar solution and I took the opportunity to use jQuery 1.4's new syntax for object creation (so this is 1.4 code only - see comments for a 1.3.x solution). Differences? I exclude hyperlinks set to the hash symbol (#) which shouldn't be found anyway (graceful degredation people!), "mailto" links, and I don't find link element's citations (blockquote "cite" property). I also believe his script would grab image information, but I'm not entirely sure, mine only searches hyperlinks. I also opted not to exclude listings of duplicate hyperlink values. If it's found twice, it lists it in the footer twice. Less JS processing, and more clear to the visitor (in my opinion).
Expected Issues: It requires JavaScript (and the jQuery library included on your page). If JavaScript is enabled but CSS is disabled, the hidden content will be visible to the user.
On to the code!
First thing's first, we should find the links in our code that we'd like to target. For my situation, I have a content class defined on my page for all content, and the column that contains the actual body is called ".col2_right" (yes, I know, ignore the fact of the poor naming scheme). So, in jQuery, we're going to target all hyperlinks found in the col2_right and content classes, but we don't want to include links to hashes or mailto links. I've also removed listing to nofollow links, but that is my choice (probably not a good one, but I digress).
We'll also need some sort of container to keep these found links wrapped in. I chose to use a fieldset and legend, you could just as easily create a DIV and a H2 or other tags for your own purposes. I also want to create an ordered list to match the found hyperlinks.
Here comes the real center, meaty goodness of the script: looping through our list of found hyperlinks, creating a little notification text next to the hyperlink's text, and add the hyperlink URL itself to the footnote section in the ordered list as a list item.
We use jQuery's each() method to loop through the items in the array, grab the link's URL so that we can do some testing on it, and modify it's value for inclusion in to the footnotes. Some links may be relative URLs, but that doesn't mean much to someone who doesn't know what a relative URL is. In fact, it would probably confuse me too at first. I then create a span tag to hold the associated footnote number (the ListApart article used a superscript tag, I found regular text is more easily readable), add a class to it so it's only visible when printed, and create my list item element with the URL from our link, and place those elements in to the document in the appropriate places with the appendTo jQuery function.
Last but not least, we append our entire footnote to the end of our content body section. The full code is below.
Note the added "if" statement to check the length of the links variable. If it is empty, we did not find any links and don't want to create any extra markup when printing the page.
Oh, and the CSS: ".print_only { display:none; }" This should be placed in your normal style sheet, and leave it out from your print style sheet. If you don't have a print style sheet, extend it a bit: @media print { .print_only { display:none; } }
Note: Thanks to Stiles to provide some fixes and compatibility changes for jQuery 1.3.x.
Inspired by the article's intentions, I decided to use some jQuery to whip up a similar solution and I took the opportunity to use jQuery 1.4's new syntax for object creation (so this is 1.4 code only - see comments for a 1.3.x solution). Differences? I exclude hyperlinks set to the hash symbol (#) which shouldn't be found anyway (graceful degredation people!), "mailto" links, and I don't find link element's citations (blockquote "cite" property). I also believe his script would grab image information, but I'm not entirely sure, mine only searches hyperlinks. I also opted not to exclude listings of duplicate hyperlink values. If it's found twice, it lists it in the footer twice. Less JS processing, and more clear to the visitor (in my opinion).
Expected Issues: It requires JavaScript (and the jQuery library included on your page). If JavaScript is enabled but CSS is disabled, the hidden content will be visible to the user.
On to the code!
First thing's first, we should find the links in our code that we'd like to target. For my situation, I have a content class defined on my page for all content, and the column that contains the actual body is called ".col2_right" (yes, I know, ignore the fact of the poor naming scheme). So, in jQuery, we're going to target all hyperlinks found in the col2_right and content classes, but we don't want to include links to hashes or mailto links. I've also removed listing to nofollow links, but that is my choice (probably not a good one, but I digress).
We'll also need some sort of container to keep these found links wrapped in. I chose to use a fieldset and legend, you could just as easily create a DIV and a H2 or other tags for your own purposes. I also want to create an ordered list to match the found hyperlinks.
Here comes the real center, meaty goodness of the script: looping through our list of found hyperlinks, creating a little notification text next to the hyperlink's text, and add the hyperlink URL itself to the footnote section in the ordered list as a list item.
We use jQuery's each() method to loop through the items in the array, grab the link's URL so that we can do some testing on it, and modify it's value for inclusion in to the footnotes. Some links may be relative URLs, but that doesn't mean much to someone who doesn't know what a relative URL is. In fact, it would probably confuse me too at first. I then create a span tag to hold the associated footnote number (the ListApart article used a superscript tag, I found regular text is more easily readable), add a class to it so it's only visible when printed, and create my list item element with the URL from our link, and place those elements in to the document in the appropriate places with the appendTo jQuery function.
Last but not least, we append our entire footnote to the end of our content body section. The full code is below.
Note the added "if" statement to check the length of the links variable. If it is empty, we did not find any links and don't want to create any extra markup when printing the page.
Oh, and the CSS: ".print_only { display:none; }" This should be placed in your normal style sheet, and leave it out from your print style sheet. If you don't have a print style sheet, extend it a bit: @media print { .print_only { display:none; } }
Note: Thanks to Stiles to provide some fixes and compatibility changes for jQuery 1.3.x.
