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Clearing Web Notifications Permissions in Chrome

Tuesday, December 3rd, 2013

When implementing features which leverage HTML5 Web Notifications, specifically in Chrome, it can be rather convenient to have the ability to clear notification permissions from the host for which the feature is being implemented.

As would be expected, Chrome allows for easily managing any setting; however, one needs to navigate through quite a few of Chrome’s settings in order to locate Web Notification permissions, the path to which being:
Settings > Show advanced settings… > Content Settings > Notifications > Manage Settings…

Navigation of settings can be simplified by using Chrome’s Search box, which allows for quickly navigating to any specific setting:

While Chrome’s settings Search feature is quite useful, it still requires more interactions then desired. Fortunately, there is an even simpler approach for quickly accessing a specific setting, in this case, Notifications.

Simplifying Clearing Web Notification Permissions

Web Notification Settings can be directly accessed for all hosts via the following path:

As with any URL protocol, the above path can be bookmarked, allowing for easy and convenient management of Notifications.

Bookmarking Chrome Settings

While the focus here may be on the topic of managing Web Notification settings, it is important to note that any Chrome setting can be bookmarked as a convenience shortcut for quickly navigating to any given setting. For instance, Chrome’s cache setting can be bookmark at:

Then, commonly used settings can be accessed simply from their respective bookmarks:

Simplifying Testing of Sign-up Processes

Thursday, November 14th, 2013

When testing the various steps of account sign-up, creation and activation processess, one must be mindful of designs which call for unique email addresses to be confirmed for each new account. While this is a generally accepted approach, it does pose a slight challenge when end-to-end testing requires email activation from the address with which the account was created.

Creating multiple Accounts under the same Email Address

Recently, while implementing an account registration feature, I was looking for a simple means of creating and testing multiple user accounts against a single email address, so as to allow for continuous testing without the need to use different email addresses for each test.

Fortunately, a few clever solutions have been available all along in Gmail which can be leveraged for this very problem (in addition to others).

The Plus (+) Trick

Perhaps the simplest means of creating or generating unique email addresses for account creation which will all be sent to the same email address is to leverage the Plus (+) Trick.

For instance, suppose you are testing account creation and activation and want to confirm the sign-up process at Typically, one would want to test this feature multiple times – either by means of automated testing, manual integration testing, or the like. In order to test the account creation feature continuously using the same account, one can simply create new accounts by appending a plus (+) to their gmail user name, and postfix a unique string of charachters to the plus sign:

In this example, emails sent to any of the addresses above would all go to With this in mind, it is quite easy to continuously test account creation processess without the need to use multiple (real) email addresses.

The Dot (.) Trick

As with the Plus (+) Trick, similarly, the Dot (.) Trick can also be employed to test account creation under the same email address.

For instance, to test an account creation and activation process feature continuously using the same account, one can simply create new accounts by inserting a dot “.” within their gmail user name:

In this example, emails sent to any of these addresses above would all be sent to

Concluding Thoughts

As can be seen in the above examples, both the Plus (+) Trick and Dot (.) Trick, respectively, can be used to create and test account sign-up and activation processes against a single email address, greatly simplifying testing.

While the Dot (.) Trick is quite useful, it is obviously limited to a finite combination of pseudo-unique email addresses, and thus, it is better suited for fewer testing scenarios.

For more extensive testing scenarios, the Plus (+) Trick is much better suited, as it allows for seemingly infinite permutations of the same email address, and is ideal for generating addresses from which account creation is to be tested.

Function Modules in RequireJS

Wednesday, October 16th, 2013

Having leveraged RequireJS as part of my preferred client-side web stack for some time now, I find it rather surprising how often I recall various features from the API docs which I have yet to use, and how they may apply to a specific solution I am implementing.

One such feature is the ability to define a module as a function. While at first this may seem a rather basic feature, and indeed it is, there are quite a few practical purposes in which returning a function as a module definition can prove useful.

Function Modules

As one may expect, returning a function as a Module in RequireJS is rather straight-forward. For example, a simple random function can be defined as a module as follows:

Then, the function module can simply be invoked as follows:

Function Modules as Factories

Perhaps a more practical example of implementing a function module is in the context of a Factory Method.

For instance, a function module can be used as a convenient means of creating a specific type of object on a clients behalf based on certain conditions.

Take (an intentionally simple) example of a function module which, given a specific role type, returns a corresponding view implementation (in this example, a Backbone View) for an Editor feature:

Client code can then simply invoke the factory in order to retrieve the appropriate Editor view implementation based on the specified role type:

Defining modules as functions which serve as factory methods can help simplify client code implementations, as the responsibility of determining the type of object to create, configure, etc., can be delegated to a dedicated object; thus allowing for simpler designs which better facilitate code reuse, testing, and maintenance.

As a general rule of thumb, I typically reserve implementing modules as functions for cases in which a package level method would be appropriate, or for factory implementations. However, there are other scenarios in which function modules may apply, and so they are certainly worth noting.

You can fork the above example here.

HTML5 Input Elements on iOS

Saturday, September 7th, 2013

Perhaps some of the most important UX considerations to make are those surrounding the simplicity with which forms can be completed. This is especially important when taking into account the constraints of Mobile devices.

Input Elements and the iOS Keyboard

While implementing a form for a Mobile Web Application, I found myself in need of a way to control some of the default behaviors of the native iOS Keyboard. Specifically, I found it rather inconvenient on the user’s part to require manual closing of the keyboard of any kind, especially after submitting a form. I also found it inconvenient to have to manually turn off auto capitalization on input elements, or having to work around the default auto-correct behavior on input elements.

Fortunately, these issues (as well as others) have solutions which are readily available, both natively and programmatically.

Turning off auto-caps

By default, the iOS Keyboard displays with Caps Lock on for the first charachter on input elements of type text. For certain use-cases, such as entering usernames, this may not be desirable.

Caps Lock can be turned off by simply defining an autocapitalize attribute with a value of off on input elements:

Turning off auto-correct

As with with Caps Lock, in iOS, by default, input elements of type text have auto-correct enabled. For certain use-cases, again, such as entering usernames, this may not be desirable.

Auto-correct can be disabled by simply defining an autocorrect attribute with a value of off on input elements:

Automatically closing the Keyboard

When submitting a form, at times, the iOS Keyboard may not automatically close. This is quite a usability issue as Users should not be required to manually close the Keyboard for use-cases in which they would otherwise not expect the need do so.

A simple solution for this can be implemented by invoking the blur method on document.activeElement, which effectively allows one to programmatically hide the keyboard:

HTML5 Input Attribute Types

In addition to controlling the default behavior of the iOS Keyboard, specific types of Keyboards can be invoked simply by defining a supported HTML5 input element type.

The following examples demonstrate just how easy it is to display a context specific keyboard:

The Email keyboard can be invoked via the email input type:

The URL keyboard can be invoked via the url input type:

The Telephone keyboard can be invoked via the tel input type:

The Numeric keyboard can also be invoked via the pattern attribute, the value of which being either of the following Regular Expressions [0-9]* or \d*:

You can try the above examples here, or view the gist.

Fluent APIs and Method Chaining

Thursday, August 1st, 2013

Of the vast catalog of Design Patterns available at our disposal, often times I find it is the simpler, less prominent patterns which are used quite frequently, yet recieve much less recognition; a good example of which being the Method Chaining Pattern.

Method Chaining

The Method Chaining Pattern, as I have come to appreciate it over the years, represents a means of facilitating expressiveness and fluency when used articulately, and mere convenience in it’s less sophisticated use-cases.

Design Considerations

When considering Method Chaining, one should take heed not to simply use the pattern as merely syntactic sugar from which writing fewer lines of code can be achieved; but rather, Method Chaining should be used, perhaps more appropriately, as a means of implementing Fluent APIs which, in turn, allow for writing more concise expressions. By design, such expressions can be written, and thus read, in much the same way as natural language, though they need not be the same from a truly lexical perspective.

The resulting terseness afforded by Method Chaining, while convenient, is in most cases not in-of-itself a reason alone for leveraging the pattern.


Method Chaining, when considered purely from an implementation perspective, is perhaps the simplest of all design patterns. It’s basic mandate simply prescribes returning a reference to the object on which a method is being called (in most languages, JavaScript in particular, the this pointer).

Consider the following (intentionally contrived) example:

As can be seen, implementing Method Chaining requires nothing more than simply having methods return a reference to this.

API Simplicity

Method Chaining is typically used when breaking from traditional Command Query Seperation (CQS) principles. The most common example being the merging of both getters (Queries) and setters (Commands). I especially like this technique, as, aside from being very easy to implement, it allows for an API to be used in a more contextual manner from the developers perspective as oppossed to that specified by the API designer’s preconceptions of how the API will be used. For example:

As can be seen, the message method serves as both a getter and setter, allowing users of the API to determine how the method should be invoked based on context, as well as affording developers the convenience of needing only to remember a single method name. This technique is used quite heavily in many JavaScript libraries and has undoubtedly contributed to their success.

We could further expand on this concept by determining a method’s invocation context based on the arguments provided, or the types of specific arguments, thus, in turn, merging various similar methods based on a particular context.

An important design recommendation to consider is that if you are writing an API which violates CQS (which is quite fine IMHO), as always, API consistency is important, thus all getters and setters should be implemented in the same manner.


As was mentioned, in most cases, Method Chaining is leveraged to facilitate APIs which are intended to be used fluently (e.g. an Internal DSL). Such implementations typically provide methods which, by themselves, may have little meaning; however, when combined, allow for writing expressions which are self-descibing and make logical sense to users of the API.

For example, consider the way one might describe a Calendrical Event:

Vacation, begins June 21st, ends July 5th, recurs Yearly.

We can easily implement a Fluent API such that the above grammar can be emulated in code as follows:

The same methods can also be chained in different combinations, yet yield the same value:

Given the above example, we could further improve on the fluency of the implementation by adding intermediate methods which can, by themselves, simply serve to aid in readability, or, provide an alternate modifier for chaining:

When implementing Fluent APIs, we can design such that different logical chaining combinations can yield the same result, thus affording users of the API the convenience of determining the most appropriate expressions based on context or personal preference, even grammatically so. Illogical chaining combinations can be handled by either throwing an exception, or they can simply be ignored based on the context of a preceding invocation – though, of course, one should aim to avoid designs which allow for illogical chaining.

The Ubiquitous Example – jQuery

While Method Chaining and Fluent APIs, as with most design patterns, are language agnostic, in the JavaScript world perhaps the most well known implementation is the jQuery API; for example:

In addition to jQuery, there are numerous additional JavaScript Method Chaining and Fluent APIs of note, Jasmine in particular has a very expressive API which aligns excellently with it’s design goals. The various libraries which implement the Promises/A spec also provide very clear and concise Fluent APIs.

Concluding Thoughts

Over the years I have leveraged Method Chaining to facilitate the design of Fluent APIs for various use-cases. The two patterns, when combined, can be especially useful when designing Internal DSLs; either third-party libraries, or APIs specific to a particular business domain.

Invoking Native Mobile Applications with URI Schemes

Wednesday, July 10th, 2013

In a previous article, I outlined how the native iOS Keyboard and it’s behaviors can be managed with HTML5 input types. In addition to this, iOS, Android and most A-Grade Mobile platforms implement standard URI Schemes (or parts thereof), which allow for easily launching native applications.

URI Schemes

When considering URI Schemes, more commonly (though incorrectly) referred to as protocols, one typically thinks in terms of the more ubiquitous schemes: http, ftp, file, mailto, about, data:uri and so forth. However, as with these and other common URI Schemes, there are additional schemes which allow for various practical applications in the context of Mobile Web Apps; the most common of which being the ability to invoke a platform’s native phone or messaging application, respectively.

URI Schemes and Mobile Devices

In the context of Mobile Web Applications, the tel, and sms URI Schemes are perhaps the most common and applicable; providing a simple means of invoking their corresponding native applications. The following are basic examples which work across all major mobile platforms.

The tel URI Scheme

The tel URI Scheme allows for launching a device’s native Phone application in the context of the phone number specified:

The sms URI Scheme

The sms URI Scheme allows for launching a device’s native Messaging application to send an sms message, or to send an sms message to the phone number specified:

As can be seen in the above examples, hyphens are used in the same manner as one would typically specify a phone number; however, use of visual separators are purely optional – they can be used to aid in readability if desired, but are otherwise ignored when parsing the URI.

As a general best practice, one should take care to ensure both tel and sms URI Schemes are defined in lowercase, so as to ensure portability across platforms. Additionally, it is important to note that the sms scheme is not implemented to completion against it’s formal definition on any platform (see section 2.2 of rfc5724); thus, an sms message body, or sending an sms message to multiple recipients is not supported.

While there is nothing particularly ground breaking about these URI Schemes, or technically complex for that matter, they do prove to be quite useful in the context of Mobile Web Applications. As such, they are certainly worth noting as each can be leveraged to improve the usability of an application.