SYS-CON MEDIA Authors: Yeshim Deniz, Pat Romanski, Gary Arora, Zakia Bouachraoui, Liz McMillan

Blog Feed Post

Dispatches From the Edge: Polymorphic Records

We have good news for anyone using the experimental polymorphism framework from within SproutCore. You’ll be glad to know that it has now made its way into the official datastore framework as part of SC.Record. If you have been using this framework, you’ll be even more glad to learn that polymorphic records are now significantly faster and more memory efficient. As well, this change includes a critical bug fix that resulted in polymorphic records getting mismatched when their id was changed.

For those interested in what this change means, here’s how it works. First, if you’re not familiar with polymorphism, it’s similar to inheritance, but differs in that polymorphic subclasses share a common “identity”. Here’s what that means with respect to the data model. In typical inheritance, the subclasses inherit the traits (attributes) of their superclass, but they can’t stand-in for that superclass (i.e. their identity or type is unique). In polymorphic inheritance, the subclass still inherits the traits of the superclass, but is now also considered to be the “same” type as the superclass. This means that when you query for records of a polymorphic super type, you’ll also receive records of all the polymorphic sub types.

This is especially useful functionality, because data is often stored in exactly this type of generic manner. It’s typical in SQL databases to have a large table where certain attributes apply to one specific subtype of the data, other attributes apply to another subtype and some attributes apply to all. With polymorphism, we can model this situation precisely.

So how do we use it in SproutCore? It’s simply a matter of adding the isPolymorphic property to a record class and extending it. Let’s look at an example from the SC.Record documentation that will hopefully clear up any remaining confusion on how polymorphism works.

// This is the "root" polymorphic class. All subclasses of MyApp.Person 
// will be able to stand-in as a MyApp.Person.
 MyApp.Person = SC.Record.extend({
   isPolymorphic: true
 });
 
// As a polymorphic subclass, MyApp.Female is "equal" to a MyApp.Person.
 MyApp.Female = MyApp.Person.extend({
   isFemale: true
 });
 
// As a polymorphic subclass, MyApp.Male is "equal" to a MyApp.Person 
// also. Not it is not "equal" to a MyApp.Female.
 MyApp.Male = MyApp.Person.extend({
   isMale: true
 });
 
// Load two unique records into the store.
 MyApp.store.createRecord(MyApp.Female, { guid: '1' });
 MyApp.store.createRecord(MyApp.Male, { guid: '2' });
 
// Now we can see that these records are in fact "equal" to each other. 
// Which means that if we search for "people", we get "males" & 
// "females".
 var female = MyApp.store.find(MyApp.Person, '1'); // Returns record.
 var male = MyApp.store.find(MyApp.Person, '2'); // Returns record.
 
// These records are MyApp.Person as well as their unique subclass.
 SC.kindOf(female, MyApp.Female); // true
 SC.kindOf(male, MyApp.Male); // true

Enjoy!

Read the original blog entry...

More Stories By Charles Jolley

Charles Jolley is the creator of SproutCore and CEO of Sproutit, which provides consulting and software services for building SproutCore applications on the web. He has helped build some of the most popular RIAs on the web today.

Latest Stories
While a hybrid cloud can ease that transition, designing and deploy that hybrid cloud still offers challenges for organizations concerned about lack of available cloud skillsets within their organization. Managed service providers offer a unique opportunity to fill those gaps and get organizations of all sizes on a hybrid cloud that meets their comfort level, while delivering enhanced benefits for cost, efficiency, agility, mobility, and elasticity.
Isomorphic Software is the global leader in high-end, web-based business applications. We develop, market, and support the SmartClient & Smart GWT HTML5/Ajax platform, combining the productivity and performance of traditional desktop software with the simplicity and reach of the open web. With staff in 10 timezones, Isomorphic provides a global network of services related to our technology, with offerings ranging from turnkey application development to SLA-backed enterprise support. Leadin...
DevOps has long focused on reinventing the SDLC (e.g. with CI/CD, ARA, pipeline automation etc.), while reinvention of IT Ops has lagged. However, new approaches like Site Reliability Engineering, Observability, Containerization, Operations Analytics, and ML/AI are driving a resurgence of IT Ops. In this session our expert panel will focus on how these new ideas are [putting the Ops back in DevOps orbringing modern IT Ops to DevOps].
Darktrace is the world's leading AI company for cyber security. Created by mathematicians from the University of Cambridge, Darktrace's Enterprise Immune System is the first non-consumer application of machine learning to work at scale, across all network types, from physical, virtualized, and cloud, through to IoT and industrial control systems. Installed as a self-configuring cyber defense platform, Darktrace continuously learns what is ‘normal' for all devices and users, updating its understa...
Enterprises are striving to become digital businesses for differentiated innovation and customer-centricity. Traditionally, they focused on digitizing processes and paper workflow. To be a disruptor and compete against new players, they need to gain insight into business data and innovate at scale. Cloud and cognitive technologies can help them leverage hidden data in SAP/ERP systems to fuel their businesses to accelerate digital transformation success.
Most organizations are awash today in data and IT systems, yet they're still struggling mightily to use these invaluable assets to meet the rising demand for new digital solutions and customer experiences that drive innovation and growth. What's lacking are potent and effective ways to rapidly combine together on-premises IT and the numerous commercial clouds that the average organization has in place today into effective new business solutions.
Concerns about security, downtime and latency, budgets, and general unfamiliarity with cloud technologies continue to create hesitation for many organizations that truly need to be developing a cloud strategy. Hybrid cloud solutions are helping to elevate those concerns by enabling the combination or orchestration of two or more platforms, including on-premise infrastructure, private clouds and/or third-party, public cloud services. This gives organizations more comfort to begin their digital tr...
Keeping an application running at scale can be a daunting task. When do you need to add more capacity? Larger databases? Additional servers? These questions get harder as the complexity of your application grows. Microservice based architectures and cloud-based dynamic infrastructures are technologies that help you keep your application running with high availability, even during times of extreme scaling. But real cloud success, at scale, requires much more than a basic lift-and-shift migrati...
David Friend is the co-founder and CEO of Wasabi, the hot cloud storage company that delivers fast, low-cost, and reliable cloud storage. Prior to Wasabi, David co-founded Carbonite, one of the world's leading cloud backup companies. A successful tech entrepreneur for more than 30 years, David got his start at ARP Instruments, a manufacturer of synthesizers for rock bands, where he worked with leading musicians of the day like Stevie Wonder, Pete Townsend of The Who, and Led Zeppelin. David has ...
Darktrace is the world's leading AI company for cyber security. Created by mathematicians from the University of Cambridge, Darktrace's Enterprise Immune System is the first non-consumer application of machine learning to work at scale, across all network types, from physical, virtualized, and cloud, through to IoT and industrial control systems. Installed as a self-configuring cyber defense platform, Darktrace continuously learns what is ‘normal' for all devices and users, updating its understa...
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
Addteq is a leader in providing business solutions to Enterprise clients. Addteq has been in the business for more than 10 years. Through the use of DevOps automation, Addteq strives on creating innovative solutions to solve business processes. Clients depend on Addteq to modernize the software delivery process by providing Atlassian solutions, create custom add-ons, conduct training, offer hosting, perform DevOps services, and provide overall support services.
Contino is a global technical consultancy that helps highly-regulated enterprises transform faster, modernizing their way of working through DevOps and cloud computing. They focus on building capability and assisting our clients to in-source strategic technology capability so they get to market quickly and build their own innovation engine.
When applications are hosted on servers, they produce immense quantities of logging data. Quality engineers should verify that apps are producing log data that is existent, correct, consumable, and complete. Otherwise, apps in production are not easily monitored, have issues that are difficult to detect, and cannot be corrected quickly. Tom Chavez presents the four steps that quality engineers should include in every test plan for apps that produce log output or other machine data. Learn the ste...
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...