Archive for the ‘Developer’ Category

Lazy developers make for bad user experiences

March 18, 2013

As a developer I can appreciate that dealing with user input is a pain. Dealing with anything messy humans do is always more annoying than handling nice clean inputs from an API. Developers and designers are human too, and they should think about the experiences they are creating, and how a little bit of consideration for the user can turn a frustrating process into a moment of delight.

  • Required fields: Indicate visually when a field is required, and ask yourself if the field is actually required for what the user is trying to do (delight them and they’ll come back and share more information incrementally). Especially in a world of security leaks I like to minimize what I share and you should help with that.
  • Formatting (phone and credit card numbers) is irrelevant: Should I enter my cell as (425)-555-5555, 4255555555, 425 555 5555 or something else? Actually all of those should be valid as it doesn’t take much effort to strip out spaces, dashes and brackets when you’re validating a credit card or phone number. If you need a particular format for your database or display then re-format it… but don’t force the user to comply with a rigid structure to make your life easier.
  • Don’t be redundant: Don’t make me tell you what type of credit card I’ve entered the number for. Using a simple issuer lookup you can tell me if I just entered an Amex or a Mastercard. If you need me to write an look-up API for you I will, just leave a note in the comments.
  • Passwords are a pain to remember: Just because you think the password rules on your site are obvious (at least one capital, one digit, only special character is an underscore and it must start with a different letter than your username) users have lots of passwords. Give them a reminder next to a where they have to enter it what those arbitrary rules are, ideally on initial entry and as an absolute must if validation fails.
  • Don’t ask me the same thing twice: In the US a ZIP code can tell me the City and State. Same in Australia or New Zealand or the UK and pretty much anywhere else. Can anyone explain to me why I have to enter both 90210 and Beverly Hills, California on a million forms? By all means display the City/State for me to confirm but don’t waste my time asking me to do a computers job. That thing I said about look-up APIs earlier, still true
  • Don’t be forgetful: Computers are good at remembering stuff, if developers are not being lazy. If I fill in a field or check a box on a form and something goes wrong with validation the only field I should reasonably be expected to re-enter is the password (and if you validate that and it passes assume I know my password and don’t make me rekey those asterisks again). If I checked “accept Ts&Cs” or “Don’t email me crap” the first time… I probably meant it so don’t forget it because I didn’t get my phone number in exactly the format you like.
  • On-the-fly, context sensitive validation is awesome: Make use of onchange and onblur events and Ajax to check each field as I go to save the user scrolling up and down a page to find what failed. Basic validation, like credit card checksums, for fields that are easy to miskey should not require a full form submission
  • When things go wrong, show me: When you finally get to a full round trip validation and have to show the user some errors you need correcting don’t just bundle some obscure messages at the top of the page – use visual cues and clear explanations to guide them to get it right

By making the process simple and eliminating points where the user can stumble your helping ensure that your form is not a roadblock where the user might get frustrated and abandon the process. When you go to the supermarket you look for the shortest line, or the easiest way to checkout, and you get frustrated if the process isn’t smooth. It’s just the same on the Web.

Even if you think you’ve gone beyond the things I mention above have you gone far enough? Are you watching your logs and other telemetry to see what fields users are stumbling on? Could you streamline the process further?

Your challenge: As designers and developers you should embrace the opportunity to streamline your users experience, and use every tool at your disposal to deliver a great user experience.

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Posted in Developer, Edge Case Design, UX, Web | Leave a Comment »

GUIDs in JavaScript

July 14, 2011

Update: From the comments below it looks like I arrived at the same solution as someone else had  come up with earlier. Recommend you check out the Broofa.com code as they have done more work on making it more performant and robust.

—-

 

 

A while ago I needed a quick and simple way to generate a GUID in a JavaScript project but most of the examples that I could find were either slow, cumbersome or didn’t always pass GUIDs that would pass verification, so I had an attempt at writing my own that had to be performant, small and robust enough to use in a real world environment at scale.

 

Well, after generating 50 million GUIDs across all the mainstream browsers (and some pretty obscure ones!) in my other logging system (an internal project, not jsErrLog – though it’s used there as well) I’m happy that it’s behaving well enough to share so with no further ado…

 

function guid() { // http://www.ietf.org/rfc/rfc4122.txt section 4.4

                return ‘aaaaaaaa-aaaa-4aaa-baaa-aaaaaaaaaaaa’.replace(/[ab]/g, function(ch) {

                                var digit = Math.random()*16|0, newch = ch == ‘a’ ? digit : (digit&0×3|0×8);

                                return newch.toString(16);

                                }).toUpperCase();

}

 

Regular expressions, nested functions and logical operators… probably the most I’ve every crammed into that few characters though if you’re really obsessive you can crunch it down even further to one line at the cost of readability:

 

guid=function(){return”aaaaaaaa-aaaa-4aaa-baaa-aaaaaaaaaaaa”.replace(/[ab]/g,function(ch){var a=Math.random()*16|0;return(ch==”a”?a:a&3|8).toString(16)}).toUpperCase()};

Posted in Developer, Javascript, Uncategorized | 3 Comments »

Let Frebber make your FREB files easier to handle

June 16, 2011

If you have used IIS for any length of time you have probably come across the term FREB. If you don’t know what it is then you should read this great introduction to Failed Request Tracing in IIS. It’s applicable to IIS7 and above and is a great tool.

At a high level FREB produces an XML file containing details of errors you are interested in – you specify the error code you want to trap, the execution time threshold or a number of other filters – and provides a wealth of information about what was happening under the covers in IIS.

The problem with FREB Tracing though is that it’s very easy to end up with a folder containing hundreds or even thousands of error reports – all named a variant on fr000123.xml – and you have no way to quickly tell which where the ones with details of 401.3 errors, or which ones failbed because they took more than 5 seconds to execute.

Well, thanks to the wonders of powershell there’s now a simple solution.

Frebber scans the output directory where your FREB logs are stored and copies the files into a new subdirectory (called .Frebber of course) while at the same time renaming the files based on the nature of the error report they contain.

For instance fr000012.xml may contain details of an HTTP 415 error and took 2571ms to execute, so the file would be renamed 415_STATUS_CODE_2571_fr000012.xml

It’s a fairly simple script and if you have a look at the XML format inside a FREB report you’ll be able to see how to adapt it quickly to your particular needed. Meanwhile feel free to use the example below, and I’d love to hear any comments or suggestions in the comments.

Oh, it does make one pretty big assumption… that your FREB files are going to the default directory. If that’s not that case then you will need to modify that line (I might get around to making the script more complete and add parameter for source and destination directories and some renaming selection criteria but right now this works pretty well for me 

$frebDir = "c:inetpublogsFailedReqLogFilesW3SVC1"
echo "Frebbering...."
$fileEntries = Get-ChildItem $frebdir*.* -include *.xml;
$outDir = $frebDir + ".Frebber"
# Create the directory for the Frebberized files
$temp = New-Item $outDir -type directory -force
# copy in the freb.xsl so you can still view them
Copy-Item ($frebDir+"freb.xsl") $outDir
$numFrebbered = 0
foreach($fileName in $fileEntries) 
{
    [System.Xml.XmlDocument] $xd = new-object System.Xml.XmlDocument
    $frebFile = $frebDir + $fileName.name;
    $xd.load($frebFile)
    $nodelist = $xd.selectnodes("/failedRequest")
    foreach ($testCaseNode in $nodelist) 
    {
        $url = $testCaseNode.getAttribute("url")
        $statusCode = $testCaseNode.getAttribute("statusCode")
        $failureReason = $testCaseNode.getAttribute("failureReason")
        $timeTaken =  $testCaseNode.getAttribute("timeTaken")
        $outFile = $frebDir + ".Frebber" + $statusCode + "_" + $failureReason + "_" + $timeTaken + "_" + $fileName.name;
        Copy-Item $frebFile $outFile
        $numFrebbered +=1
    }
}         
echo "Frebbered $numFrebbered files to $outdir."

Posted in Developer, Uncategorized, Web | 1 Comment »

jsErrLog: now alerts via XMPP

June 13, 2011

Although it’s nice to know that the jsErrLog service is sitting there recording errors that your users are seeing it does put the onus on developers to remember to check the report page for their URL to see if there have been any issues.

To make things a little more pro-active registered users can now connect to an XMPP (Google Chat) client (eg Digsby) and every time there’s a new error reported the bot will send you an alert.

Because you might get a flurry of messages if you deploy a version and there’s an error, or a 3rd party component has a problem the bot also listens to a set of messages so it’s easy to suspect the alerting (or turn it back on when the problem has been fixed).

At the moment there a few restrictions:

·         alerts have to match a specific URL

·         for a given user all alerts are turned off/on (no per URL granularity)

·         alerting is only available to users who’ve made a donation or promoted jsErrLog

The reason for the first one is a limitation with the way AppEngine lets me query data (unlike SQL the GQL query language does not support the CONTAINS or LIKE verbs)… I’m looking for a solution to that

The second is a feature that I plan to add soon depending on demand.

The third… at the moment it takes a little bit of setup to add new users so I’m adding it as the first freemium feature though this may change. If you want that enabled please let me know the URL you are monitoring and your Google Chat ID and I’ll let you know what else you need to do to enable it…

Posted in Developer, Javascript, jsErrLog, Uncategorized, Web | Leave a Comment »

jsErrLog – now with XML

June 9, 2011

To help analyze data from jsErrLog – my Javascript Error Log service – I added a new feature today: An XML data feed for reports.

You can access a report as normal and view it in the browser, eg the sample report and on there you will now see a direct link to the XML version of the report.

If you know the name of the URL you want to report against then you simple access it via http://jserrlog.appspot.com/report.xml?sn=http://blog.offbeatmammal.com where the parameter after the sn is the URL you want to query.

Image001

Both the report and the XML show up to the last 500 results for the URL. I plan to add limits to the XML feed, and pagination to the HTML report in a future release (let me know in the comments what’s more important, and any other requests). I would like to implement a full OData feed for the data but haven’t found a good Python / App Engine sample out there yet…

One great thing about having the data available as an XML source is that you can add it as a Data Source in Excel and from there filter and sort to your hearts content

Image002

Posted in Developer, Javascript, jsErrLog, Uncategorized, Web | Leave a Comment »

Azure Dynamic Compression

April 9, 2011

On a normal Windows IIS installation it’s pretty easy to turn on dynamic compression for WFC and other served content to reduce the amount of bandwidth you need to consume (important when you are charged by the byte) – you just change the server properties to enable dynamic as well as the more common static compression.

With Windows Azure though it’s a little more interesting because with roles dynamically assigned and started from a standard instance you don’t have much control … unless you’re used to doing everything from the command line …

Luckily one of the nice things that you can do with an Azure role is script actions to take place as part of the initialization. The process is as simple as adding the commands you need to execute to a batch script that gets deployed as part of your project and calling it at the relevant time.

The first thing you script needs to do is to turn dynamic compression on for the server in that role:

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config -section:urlCompression /doDynamicCompression:true /commit:apphost

You then want to set the minimum size for files to be compressed (in bytes)

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config -section:system.webServer/httpCompression -minFileSizeForComp:50 /commit:apphost

Finally your script should specify the MIME types that you want to enable compression for

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config /section:httpCompression /+dynamicTypes.[mimeType='application/xml',enabled='true'] /commit:apphost

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config /section:httpCompression /+dynamicTypes.[mimeType='application/atom+xml',enabled='true'] /commit:apphost

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config /section:httpCompression /+dynamicTypes.[mimeType='application/json',enabled='true'] /commit:apphost

If you have a problem with MIME types like atom+xml not registering properly you may need to escape the plus sign and replace the string with ‘atom%u002bxml’ – I’ve had success with both methods

You can add as many MIME types as you need to the list, and remember that sometimes you also need to specify the characterset you are using

·         “%SystemDrive%WindowsSystem32inetsrvappcmd.exe” set config /section:httpCompression /+dynamicTypes.[mimeType='application/xml;charset=utf-8',enabled='true'] /commit:apphost

And then when you’re done exit the script to tidy up gracefully

·         exit /b 0

Once you have combined those steps together in a script and saved it as (eg) EnableDynamicCompression.cmd you should add the script to your Visual Studio project and make sure you select “Copy Always” in the properties for the file to ensure it gets correctly deployed.

Finally you need to add a reference to that startup script in your project’s ServiceDefinition.csdef file and then deploy your project as normal.

    <Startup>
        <Task commandLine=”EnableDynamicCompression.cmd” executionContext=”elevated” taskType=”simple”></Task>
    </Startup>

Finally… how do you know if it’s working or not? The thing that tricks people a lot of the time and makes them think it’s broken is that if they are behind a corporate proxy server that often un-compresses the data for you on the way past. You can check yourself using a tool like Fiddler to examine the response and make sure it has been gzipped or you can visit http://www.whatsmyip.org/http_compression/ and test that way (the latter is good if you are behind a proxy which interferes with the compression).

Posted in Azure, Developer, Uncategorized | 2 Comments »

jQuery image animations

March 28, 2011

Working on a personal project over the weekend I needed a better way to provide a central image to a site. The image was the major draw card for the site and we wanted to place links and other content on and around the image.

As we wanted to showcase multiple images the easiest solution was to animate the image replacement with jQuery but we realized the problem with that was the links and floating content really needed to move depending on the underlying image.

A combination of jQuery, CSS and old fashioned Javascript produced a fairly simple solution where it’s easy for us to swap the images for new creative content and via javascript mapipulate where the captions need to move to.

http://blog.offbeatmammal.com/samples/play/slider.html

Given a bit more time I’ll tweak the scripts to pick up the starting location from the CSS rather than hard coding in two places, and optimze the code and CSS a bit more, but as a proof of concept it was pretty effective.

After playing with the jsErrLog javascript error reporting code (a mixture of javascript and Python for AppEngine) it was nice to do something more front-end oriented.

Posted in Developer, Uncategorized, Web | Leave a Comment »

update: New version of the Javascript debugger

March 18, 2011

Although jsErrLog, my “Web Watson” has only been out a couple of days I had a great suggestion to let developers add some additional context to errors that are being trapped.

To support this I’ve added a new parameter jsErrLog.info that’s a string variable you can update at any time (after the library has been registered on your page of course) and the first 512 characters simply get passed through to the report database.

To use this new feature simply add a line that updates what you want passed through with the data you want passed and if the error handler gets called then the data will be transferred to the database

jsErrLog.info = “Populated the Info Message to pass to logger”;

Any other features you think are worth adding?

Posted in Developer, Javascript, jsErrLog, Uncategorized, Web | Leave a Comment »

Watson for the web – trapping Javascript errors

March 16, 2011

A while ago I wrote a small piece of JavaScript code that I needed to be able to integrate into lots of different sites to help streamline the Silverlight experience, but it was important that I didn’t break anyone’s existing code.

While we did extensive testing with the partners before we deployed it there was always the worry that a combination of browser and OS and plug-in we’d not tested would cause a problem we’d not foreseen.

As websites get more complex, and HTML5 brings more of the heavy lifting back to rely on JavaScript to build really dynamic experiences so my little nagging concern was just going to keep on getting bigger.

While you can wrap every statement in a Try…Catch loop and deal with exceptions that way it’s not the most efficient, and if you’re integrating libraries from a  lot of different sources then it’s not really practical.

As luck would have it two of the browsers had already implemented the key to the solution… the humble JavaScript window.onError function. In IE and Firefox it allowed you to attach an event handler that would kick in whenever an un-trapped error occurred and allow you do to whatever you needed to manage the problem.

I took that functionality and build a small script that could be injected via a single line of JavaScript into the page you want to monitor that would catch any unhandled error condition and report back to a remote cloud service the script, the error, the browser and OS versions so a developer could quickly and easily re-create the test scenarios. The code is available at jsErrLog.

Then because Chrome, Safari and Opera didn’t support the onError function I rather shelved the project. Just a few days though with the release of Chrome v10 another browser could be added to the support matrix for remote error reporting (and as the fix is in the WebKit core we can only hope that a release of Safari greater than v5 will roll out support as well)

While I wait for Safari and hopefully Opera to catch up with this I’m making a couple of other small tweaks to the code to make it a bit more reliable, as well as adding some extra functionality to allow developers to pass additional information back to the reporting database to help with debugging their specific apps.

Check it out , kick the tires and let me know if you have any feedback…

Posted in Developer, Javascript, jsErrLog, Uncategorized, Web | 8 Comments »

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