Monday, March 8. 2010
jQuery Printed Footer Links
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. 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. 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 happen to know that my domain forces www for the subdomain so I've added that in, fix that up as you like. 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.
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; } }
Inspired by the article's intentions, I decided to use some jQuery to whip up a similar 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. 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 happen to know that my domain forces www for the subdomain so I've added that in, fix that up as you like. 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.
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; } }
Sunday, February 28. 2010
YSlow: Getting a better score and a faster site.
I decided that it was finally time I took a serious look at increasing the YSlow score for our websites. I was under the impression that browsers would automatically cache (by default anyway) certain graphic elements to save on bandwidth, but our staff website has a repeating background image for a left hand navigation bar, and it would disappear for a fraction of a second while reloading the other page; this told me that something was not right, and YSlow might be the answer I was looking for (and that my PHP framework of choice was not to blame).
YSlow:
Initial Score: 67
I choose the smallest size images exported from Photoshop, and if I ever use a PNG, I use a great tool called "PNGGuantlet" (Windows only) which compresses PNGs while also removing the alpha channel problems that make PNGs appear with different colors than they were intended to. I also have compressed my main JS file, and CSS file(s). All XHTML should be valid (unless I updated a link and forget to escape an ampersand), the DOCTYPE is listed, character set is given, and all non-background images contain height and width properties. Oh, I also have a default favicon.ico file. These are all good recommendations to do regardless, and in doing so YSlow gave me a pretty decent score (albeit, not that great if it was a test in school).
Two modifications to YSlow's scoring:
1. I am not Amazon. I don't necessarily need a CDN for my content.
2. I don't need a subdomain to house my CSS, JS, and images. If I end up storing videos, that already has a subdomain set up and ready.
Therefore, I modified YSlow's grading scheme. To do so, there is a dropdown menu to the right of the 4 tabs in the YSlow toolbar, it is labelled "YSlow(V2)". Click the "Edit" button to the immediate right of that. In my scheme, I disabled "Use a Content Delivery Network (CDN)" and "Use cookie-free domains". You cannot overwrite the rule set, so you have to save it as something else, I named mine "SSPL" since that is the website domain that I care about (for work). Different websites have different criteria, so it only makes sense to name it something related to the website you are concerned about. Go through and uncheck what you don't believe applies to you. If you're uncertain, leave it checked. This little configuration raises my grade up already - that was easy.
Here are the .htaccess rules I've added to raise my own score, what they're for and why I chose to make them:
Enable GZip'ing of components:
The AddOutputFilterByType DEFLATE [list of mimetypes] was the command I used to gzip the particularly listed files that have such a MIME-Type: html, txt, js, css, js (variation), json, json (variation). Some browsers read JSON and JavaScript as an application mime-type whereas others read it as a text type, I figured I would simply cover my bases. Although these are ASCII types, you could just as easily gzip binary types, such as GIF, JPG, or PDF (though theoretically they should already be compressed and you're just adding extra work for the server).
Configure ETags:
From what I have read, ETags are a mixed breed. They can have some benefits, but they can also have some detractions. Again, considering that I'm not Amazon and I will be enabling the Expires heading, I opted to simply disable ETags. You can disable ETags in Apache under an .htaccess file with the unset rule above, along with the FileETag None to cover most supporting browsers (one would hope). I wasn't able to find any examples on how to properly "configure" ETags so that YSlow would not complain other than to simply turn them off. ETags, from what I've read, are a variation on telling the browser to cache certain files in a certain manner, but it doesn't work on any website that is run on multiple servers for the same content. Either way, I opted for the Expires heading which made ETags rather redundant from what I could tell.
Enabling an Expires Heading:
It appears that in Apache, by default, Expires headings are disabled, and just like mod_rewrite, you must explicitly tell Apache that you wish to use it, so the first thing you have to do is turn it on: "ExpiresActive On". Once that is done, there are a few ways to set the expiry time; I opted to use a human readable implementation, and YSlow expects a "far future" date (from the date last modified). As one of my sites is currently built with HTML files pulling in a template, the original files won't typically be modified for a long time, so I had to make my future date a FAR future date (10 years from last modification) - your experience may vary. For further information on Expires, take a look at the Apache documentation for mod_expires.
Additional speed enhancements:
I recently read that if you have a framework that may take some time figuring out what data must be displayed prior to even getting it to the server, it may be a good idea to flush the buffer so that the data that can be sent to the browser can be sent prior to everything else - such as the document head which contains the page title, CSS, and sometimes JS. That way, while the rest of the page is being rendered by the server, the JS/CSS has time to download. This is actually why I decided to leave my JS at the top of my website rather than placing it in the footer. I live by graceful degredation, but if the page loads before the JS does, it can also cause a screen flicker which is against accessibility guidelines for HTML. In this case, it was possible speed for accessibility - I choose accessibility. I personally really don't want me, or my client(s) getting sued for accessibility issues because "Oh hey, it loads a second faster now!". If you had an interactive rich website such as Facebook or MySpace, I'd imagine you'd have to place JS in the footer and have a separate, accessible domain for others...if that's even easily possible. Anyway, what I did with flushing the output buffer was to (in PHP) modify my template file, I called PHP's flush() function after the closing HEAD tag in the HTML template file.
Anyway, with those small tweaks and tricks, I was able to get my score up to 96. I have a B in 3 categories:
1. Expires header issue (CDN of ajax.googleapis.com, it won't recognize my CDN) as a CDN has a non-far future expiration date in the called JS file.
2. Minify CSS and JS - it is minified, so I'm not sure what it wants from me. The filesize is probably too large for an A.
3. Put JavaScript at the Bottom - I already explained why I don't want to do this, but I've left the rule in anyway.
Now my site seems to be a bit more responsive, and the background image I mentioned before no longer disappears and reappears (unless I press refresh really, really fast, confusing the browser's cache I guess).
YSlow:
Initial Score: 67
I choose the smallest size images exported from Photoshop, and if I ever use a PNG, I use a great tool called "PNGGuantlet" (Windows only) which compresses PNGs while also removing the alpha channel problems that make PNGs appear with different colors than they were intended to. I also have compressed my main JS file, and CSS file(s). All XHTML should be valid (unless I updated a link and forget to escape an ampersand), the DOCTYPE is listed, character set is given, and all non-background images contain height and width properties. Oh, I also have a default favicon.ico file. These are all good recommendations to do regardless, and in doing so YSlow gave me a pretty decent score (albeit, not that great if it was a test in school).
Two modifications to YSlow's scoring:
1. I am not Amazon. I don't necessarily need a CDN for my content.
2. I don't need a subdomain to house my CSS, JS, and images. If I end up storing videos, that already has a subdomain set up and ready.
Therefore, I modified YSlow's grading scheme. To do so, there is a dropdown menu to the right of the 4 tabs in the YSlow toolbar, it is labelled "YSlow(V2)". Click the "Edit" button to the immediate right of that. In my scheme, I disabled "Use a Content Delivery Network (CDN)" and "Use cookie-free domains". You cannot overwrite the rule set, so you have to save it as something else, I named mine "SSPL" since that is the website domain that I care about (for work). Different websites have different criteria, so it only makes sense to name it something related to the website you are concerned about. Go through and uncheck what you don't believe applies to you. If you're uncertain, leave it checked. This little configuration raises my grade up already - that was easy.
Here are the .htaccess rules I've added to raise my own score, what they're for and why I chose to make them:
Enable GZip'ing of components:
The AddOutputFilterByType DEFLATE [list of mimetypes] was the command I used to gzip the particularly listed files that have such a MIME-Type: html, txt, js, css, js (variation), json, json (variation). Some browsers read JSON and JavaScript as an application mime-type whereas others read it as a text type, I figured I would simply cover my bases. Although these are ASCII types, you could just as easily gzip binary types, such as GIF, JPG, or PDF (though theoretically they should already be compressed and you're just adding extra work for the server).
Configure ETags:
From what I have read, ETags are a mixed breed. They can have some benefits, but they can also have some detractions. Again, considering that I'm not Amazon and I will be enabling the Expires heading, I opted to simply disable ETags. You can disable ETags in Apache under an .htaccess file with the unset rule above, along with the FileETag None to cover most supporting browsers (one would hope). I wasn't able to find any examples on how to properly "configure" ETags so that YSlow would not complain other than to simply turn them off. ETags, from what I've read, are a variation on telling the browser to cache certain files in a certain manner, but it doesn't work on any website that is run on multiple servers for the same content. Either way, I opted for the Expires heading which made ETags rather redundant from what I could tell.
Enabling an Expires Heading:
It appears that in Apache, by default, Expires headings are disabled, and just like mod_rewrite, you must explicitly tell Apache that you wish to use it, so the first thing you have to do is turn it on: "ExpiresActive On". Once that is done, there are a few ways to set the expiry time; I opted to use a human readable implementation, and YSlow expects a "far future" date (from the date last modified). As one of my sites is currently built with HTML files pulling in a template, the original files won't typically be modified for a long time, so I had to make my future date a FAR future date (10 years from last modification) - your experience may vary. For further information on Expires, take a look at the Apache documentation for mod_expires.
Additional speed enhancements:
I recently read that if you have a framework that may take some time figuring out what data must be displayed prior to even getting it to the server, it may be a good idea to flush the buffer so that the data that can be sent to the browser can be sent prior to everything else - such as the document head which contains the page title, CSS, and sometimes JS. That way, while the rest of the page is being rendered by the server, the JS/CSS has time to download. This is actually why I decided to leave my JS at the top of my website rather than placing it in the footer. I live by graceful degredation, but if the page loads before the JS does, it can also cause a screen flicker which is against accessibility guidelines for HTML. In this case, it was possible speed for accessibility - I choose accessibility. I personally really don't want me, or my client(s) getting sued for accessibility issues because "Oh hey, it loads a second faster now!". If you had an interactive rich website such as Facebook or MySpace, I'd imagine you'd have to place JS in the footer and have a separate, accessible domain for others...if that's even easily possible. Anyway, what I did with flushing the output buffer was to (in PHP) modify my template file, I called PHP's flush() function after the closing HEAD tag in the HTML template file.
Anyway, with those small tweaks and tricks, I was able to get my score up to 96. I have a B in 3 categories:
1. Expires header issue (CDN of ajax.googleapis.com, it won't recognize my CDN) as a CDN has a non-far future expiration date in the called JS file.
2. Minify CSS and JS - it is minified, so I'm not sure what it wants from me. The filesize is probably too large for an A.
3. Put JavaScript at the Bottom - I already explained why I don't want to do this, but I've left the rule in anyway.
Now my site seems to be a bit more responsive, and the background image I mentioned before no longer disappears and reappears (unless I press refresh really, really fast, confusing the browser's cache I guess).
Thursday, February 18. 2010
Enabling SSL (HTTPS) via htaccess Only if Matching a Specific Domain
I had a momentary stumble today that I (somehow) couldn't get through my head. Perhaps it's just because it's been so long since I've worked with mod_rewrite, but regardless of that, here's the situation and the solution:
"The Situation" said that the situation is:
I had multiple conditions that needed to be met before a rule should be run, otherwise it should be ignored.
I am running (and require) SSL on my production server.
I am not running SSL on my development box.
I didn't want multiple .htaccess files in my SVN repository.
The solution:
"Duh." Multiple RewriteCond in a row (separated by a newline) all must be met before the RewriteRule is run.
The resulting .htaccess took the following form:
The last 3 lines dealing with rewrite in my .htaccess file are related to the code library I'm using, and are not pertinent to the problem here. The important lines are as follows:
RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP_HOST} ^staff\.sspl\.org [NC]
RewriteRule ^(.*) https://%{SERVER_NAME}/$1 [R,L]
The first condition tests to see if SSL (https protocol) is not being used in the request.
The second condition tests that the domain's host is "employees.sspl.org" (URL changed to protect the innocent).
If both tests pass, then I redirect the user to the host (and path "/$1") while using the https protocol (SSL). Done.
"The Situation" said that the situation is:
I had multiple conditions that needed to be met before a rule should be run, otherwise it should be ignored.
I am running (and require) SSL on my production server.
I am not running SSL on my development box.
I didn't want multiple .htaccess files in my SVN repository.
The solution:
"Duh." Multiple RewriteCond in a row (separated by a newline) all must be met before the RewriteRule is run.
The resulting .htaccess took the following form:
The last 3 lines dealing with rewrite in my .htaccess file are related to the code library I'm using, and are not pertinent to the problem here. The important lines are as follows:
RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP_HOST} ^staff\.sspl\.org [NC]
RewriteRule ^(.*) https://%{SERVER_NAME}/$1 [R,L]
The first condition tests to see if SSL (https protocol) is not being used in the request.
The second condition tests that the domain's host is "employees.sspl.org" (URL changed to protect the innocent).
If both tests pass, then I redirect the user to the host (and path "/$1") while using the https protocol (SSL). Done.
Friday, January 15. 2010
iPhone Server Alerting on High Load
I have a shared Dreamhost account. In fact, I manage two: my own, and work's. Typically I don't too much care about my personal site going up or down, but I have multiple sites running under my account - and our work account with Dreamhost must maintain a decent responsiveness during business hours.
I've been developing a CakePHP plugin for Prowl but haven't quite polished it well enough for release. In the meantime, my work's Dreamhost account has had major issues where the server load would spike up to 350+ (I have no idea how many cores there are). That's just ludicrous. We've recently been moved to a new server by the support staff (for the 5th time) and although the average server load is now 0.40, I don't want to take my chances without a backup plan. Enter Prowl and my iPod Touch.
(To use Prowl, you would need an iPod touch or iPhone, and paid for and installed the Prowl application; it's $4.99 as of this writing. You then need to get your API from the prowl.preks.net website.)
We'll be using the PHP 3rd party API for Prowl, built by "Fenric", and we will go to his GitHub account to get it.
Once we have the PHP API for Prowl from Fenric, we'll build some quick code to make use of it:
This little script can easily be setup with a cronjob and automatically check the current server's load and report issues. It won't report if a server is down since it must run on the server it is reporting on, but it would help inform about possible problems that should be looked at. This could easily be extended to check the MySQL long query logs, or other reporting functions.
I've been developing a CakePHP plugin for Prowl but haven't quite polished it well enough for release. In the meantime, my work's Dreamhost account has had major issues where the server load would spike up to 350+ (I have no idea how many cores there are). That's just ludicrous. We've recently been moved to a new server by the support staff (for the 5th time) and although the average server load is now 0.40, I don't want to take my chances without a backup plan. Enter Prowl and my iPod Touch.
(To use Prowl, you would need an iPod touch or iPhone, and paid for and installed the Prowl application; it's $4.99 as of this writing. You then need to get your API from the prowl.preks.net website.)
We'll be using the PHP 3rd party API for Prowl, built by "Fenric", and we will go to his GitHub account to get it.
Once we have the PHP API for Prowl from Fenric, we'll build some quick code to make use of it:
This little script can easily be setup with a cronjob and automatically check the current server's load and report issues. It won't report if a server is down since it must run on the server it is reporting on, but it would help inform about possible problems that should be looked at. This could easily be extended to check the MySQL long query logs, or other reporting functions.
Friday, January 8. 2010
Prowl, an iPhone/iPod Touch implementation of Growl
So, I hear you like the idea of push notifications on the iPhone. Oh, what's that? You wish you could send push notifications from your website and/or iPhone enabled web app? Hey, didn't you know that you can?
Thanks to Mike, and his post about what John Blyberg's been doing, I got interested in Prowl. Prowl is an iPhone app ($4.99 from the iTunes store, I believe) that lets us send push notifications to iPhone or iPod Touch devices (and hey, it works with 1st gen devices too!). You would need version 3.1 of the iPhone OS, and jailbroken phones are not officially supported (some work, some don't due to how they were jailbroken), but for the most part "it just works", and it's fast. From my tests, the longest delay I've had thus far on a "normal" importance level Prowl message was about 2-3 seconds.
So what use does it have? I'm sure there could be quite a lot. There are forums for Prowl discussions, and one of the stickied topics is just about what people are doing with custom notifications, and there are a varied slew of responses. It's quite interesting, actually.
It's not much of a surprise to anyone that's been keeping tabs on this blog (hi Mike) that I have been getting acquainted with the CakePHP framework. Because of all the uses of Prowl, and my newfound love for CakePHP, I've decided to write a plugin specifically for Prowl in CakePHP. I am not the first to create extensions for Prowl by any means, nor am I even the first to think of getting it CakePHP-ready. I've found two others after having started my work that have created Prowl Components: Jacob Oehler Morrison, and Eric Holmes (note: as of this writing, Eric Holmes' domain seems to be expired). Hopefully I can add a little bit more zest and out-of-the-box capabilities to a plugin. If anyone has some ideas, let me know about it in the comments!
Thanks to Mike, and his post about what John Blyberg's been doing, I got interested in Prowl. Prowl is an iPhone app ($4.99 from the iTunes store, I believe) that lets us send push notifications to iPhone or iPod Touch devices (and hey, it works with 1st gen devices too!). You would need version 3.1 of the iPhone OS, and jailbroken phones are not officially supported (some work, some don't due to how they were jailbroken), but for the most part "it just works", and it's fast. From my tests, the longest delay I've had thus far on a "normal" importance level Prowl message was about 2-3 seconds.
So what use does it have? I'm sure there could be quite a lot. There are forums for Prowl discussions, and one of the stickied topics is just about what people are doing with custom notifications, and there are a varied slew of responses. It's quite interesting, actually.
It's not much of a surprise to anyone that's been keeping tabs on this blog (hi Mike) that I have been getting acquainted with the CakePHP framework. Because of all the uses of Prowl, and my newfound love for CakePHP, I've decided to write a plugin specifically for Prowl in CakePHP. I am not the first to create extensions for Prowl by any means, nor am I even the first to think of getting it CakePHP-ready. I've found two others after having started my work that have created Prowl Components: Jacob Oehler Morrison, and Eric Holmes (note: as of this writing, Eric Holmes' domain seems to be expired). Hopefully I can add a little bit more zest and out-of-the-box capabilities to a plugin. If anyone has some ideas, let me know about it in the comments!