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  1. Last 7 days
  2. datatracker.ietf.org datatracker.ietf.org
    1. The WebSocket Protocol is designed on the principle that there should be minimal framing (the only framing that exists is to make the protocol frame-based instead of stream-based and to support a distinction between Unicode text and binary frames). It is expected that metadata would be layered on top of WebSocket by the application Fette & Melnikov Standards Track [Page 9] RFC 6455 The WebSocket Protocol December 2011 layer, in the same way that metadata is layered on top of TCP by the application layer (e.g., HTTP). Conceptually, WebSocket is really just a layer on top of TCP that does the following: o adds a web origin-based security model for browsers o adds an addressing and protocol naming mechanism to support multiple services on one port and multiple host names on one IP address o layers a framing mechanism on top of TCP to get back to the IP packet mechanism that TCP is built on, but without length limits o includes an additional closing handshake in-band that is designed to work in the presence of proxies and other intermediaries Other than that, WebSocket adds nothing. Basically it is intended to be as close to just exposing raw TCP to script as possible given the constraints of the Web. It's also designed in such a way that its servers can share a port with HTTP servers, by having its handshake be a valid HTTP Upgrade request. One could conceptually use other protocols to establish client-server messaging, but the intent of WebSockets is to provide a relatively simple protocol that can coexist with HTTP and deployed HTTP infrastructure (such as proxies) and that is as close to TCP as is safe for use with such infrastructure given security considerations, with targeted additions to simplify usage and keep simple things simple (such as the addition of message semantics).
  3. Jul 2021
    1. something called federated wiki which was by ward cunningham if anyone knows the details behind that or how we got these sliding panes in the first place i'm always interested

      it looks like my comment got moderated out, and I didn't save a copy. Not going to retype it here, but the gist is that:

      • Ward invented the wiki, not just the sliding panes concept.
      • Sliding panes are a riff on Miller columns, invented by Mark S. Miller
      • Miller columns are like a visual analog of UNIX pipes
      • One obvious use case for Miller columns is in web development tools, but (surprisingly) none of the teams working on browsers' built-in devtools at this point have have managed to get this right!

      Some screenshots of a prototype inspector that I was working on once upon a time which allowed you to infinitely drill down on any arbitrary data structures:

      https://web.archive.org/web/20170929175241/https://addons.cdn.mozilla.net/user-media/previews/full/157/157212.png?modified=1429612633

      https://web.archive.org/web/20170929175242/https://addons.cdn.mozilla.net/user-media/previews/full/157/157210.png?modified=1429612633

      Addendum (not mentioned my original comment): the closest "production-quality" system we have that does permit this sort of thing is Glamorous Toolkit https://gtoolkit.com/.

  4. Jun 2021
    1. Worse still is the issue of “service” layers requiring you to basically build your own ORM. To really do a backend-agnostic service layer on top of the Django ORM, you need to replace or abstract away some of its most fundamental and convenient abstractions. For example, most of the commonly-used ORM query methods return either instances of your model classes, or instances of Django’s QuerySet class (which is a kind of chained-API results wrapper around a query). In order to avoid tightly coupling to the structure and API of those Django-specific objects, your service layer needs to translate them into something else — likely generic iterables to replace QuerySet, and some type of “business object” instance to replace model-class instances. Which is a non-trivial amount of work even in patterns like Data Mapper that are designed for this, and even more difficult to do in an Active Record ORM that isn’t.

      I see what this guy means and he has a point. However, I don't think about reimplementing these things when talking about services on Django. I want a centralized place to store business logic (not glue queries) and avoid multiple developers writing the same query multiple times in multiple places. The name "service" here sucks.

    2. A second problem is that when you decide to go the “service” route, you are changing the nature of your business. This is related to an argument I bring up occasionally when people tell me they don’t use “frameworks” and never will: what they actually mean, whether they realize it or not, is “we built and now have to maintain and train our developers on our own ad-hoc private framework, on top of whatever our normal business is”. And adopting the service approach essentially means that, whatever your business was previously, now your business is that plus developing and maintaining something close to your own private ORM.

      I don't think these two things are even close to be the same thing. Django's ORM is not replaced by services, from what I know services are the ORM with the difference that they are concentrated in a module.

    1. This isn't about writing boilerplate setter properties for each field in the model, but rather about writing methods that encapsulate the point of interaction with the database layer. View code can still inspect any field on the model and perform logic based on that, but it should not modify that data directly. We're ensuring that there is a layer at which we can enforce application-level integrity constraints that exist on top of the integrity constraints that the database provides for us.

      Addresses the issue raise on this tweet. We are not writing getters and setters out of obligation or convention.

  5. Apr 2021
  6. Mar 2021
    1. Uber::Option implements the pattern of taking an option, such as a proc, instance method name, or static value, and evaluate it at runtime without knowing the option's implementation.
  7. Feb 2021
    1. provide interfaces so you don’t have to think about them

      Question to myself: Is not having to think about it actually a good goal to have? Is it at odds with making intentional/well-considered decisions?  Obviously there are still many of interesting decisions to make even when using a framework that provides conventions and standardization and makes some decisions for you...

    2. Trailblazer is an architectural pattern that comes with Ruby libraries to implement that pattern.
    1. Trailblazer offers you a new, more intuitive file layout in applications.
    2. Instead of grouping by technology, classes and views are structured by concept, and then by technology. A concept can relate to a model, or can be a completely abstract concern such as invoicing.
    3. While Trailblazer offers you abstraction layers for all aspects of Ruby On Rails, it does not missionize you. Wherever you want, you may fall back to the "Rails Way" with fat models, monolithic controllers, global helpers, etc. This is not a bad thing, but allows you to step-wise introduce Trailblazer's encapsulation in your app without having to rewrite it.
    1. I think a better, more immediately understandable name for this concept would be command object, because it lets you pass around commands (or a list of commands) as objects.

      That's the only thing you really need to know abut this pattern. The rest seems like boring implementation details that aren't that important, and that naturally follow from the primary definition above.

  8. Nov 2020
  9. Oct 2020
    1. Domain-driven design separates the model layer “M” of MVC into an application, domain and infrastructure layer. The infrastructure layer is used to retrieve and store data. The domain layer is where the business knowledge or expertise is. The application layer is responsible for coordinating the infrastructure and domain layers to make a useful application. Typically, it would use the infrastructure to obtain the data, consult the domain to see what should be done, and then use the infrastructure again to achieve the results.

      Domain Driven Design separates the the Model in the MVC architecture into an application layer, an infrastructure layer and a domain layer.

      The business logic lives in the domain layer. The infrastructure layer is used to retrieve and store data. The application layer is responsible for coordinating between the domain and infrastructure layer.

  10. May 2020
  11. Apr 2020
  12. Mar 2020
    1. The pattern below has become exceptionally useful for me (pun intended). It's clean, can be easily modularized, and the errors are expressive. Within my class I define new errors that inherit from StandardError, and I raise them with messages (for example, the object associated with the error).
  13. Feb 2020
    1. Devstringx Technologies opened for business in 2014. Today, Devstringx is India’s most recommended IT company for software product development, mobile app development and independent software testing services which headquarter in Noida, India.

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  14. Dec 2019
    1. There are thousands of to-do list apps out there, in part because no system works perfectly for everyone. I’m not going to say todo.txt is the exception, and that it will work for everyone, because that would be crazy. But todo.txt is the most flexible tool I’ve come across. In part, this is because of the sheer number of clients available, but also because the simplicity lends itself to improvisation.

      First time I've seen improvisation used like this.

  15. Nov 2019
    1. Middleware works a lot like a decorator. It doesn't alter the original API of the service, but it can augment it with new features and concerns. This has the inherent advantage of allowing all thidparty code to have an influence over the behaviour, state, and UI of a component.
    1. AdNauseam is a work in progress, with new features continually being added, tuned, and, sometimes, deprecated. If a setting no longer appears in the settings page, we have likely found a better means of implementing the design goal.
  16. Mar 2019
    1. This page is not necessarily attractive to look at but it is a thorough presentation of various features of infographics. Features are organized by topic and generally presented as a bulleted list. The focus of the page is how to use infographics for assessment; however, the page is useful to those who wish to learn how to create infographics and to identify the software tools that can be used to create them easily. Rating 4/5

  17. Feb 2019
  18. Jan 2019
    1. For large-scale software systems, Van Roy believes we need to embrace a self-sufficient style of system design in which systems become self-configuring, healing, adapting, etc.. The system has components as first class entities (specified by closures), that can be manipulated through higher-order programming. Components communicate through message-passing. Named state and transactions support system configuration and maintenance. On top of this, the system itself should be designed as a set of interlocking feedback loops.

      This is aimed at System Design, from a distributed systems perspective.

  19. Nov 2018
    1. how does misrepresentative information make it to the top of the search result pile—and what is missing in the current culture of software design and programming that got us here?

      Two core questions in one? As to "how" bad info bubbles to the top of our search results, we know that the algorithms are proprietary—but the humans who design them bring their biases. As to "what is missing," Safiya Noble suggests here and elsewhere that the engineers in Silicon Valley could use a good dose of the humanities and social sciences in their decision-making. Is she right?

    1. I don't think passing the entire http client is very idiomatic, but what is quite common is to pass the entire "environment" (aka runtime configuration) that your app needs through every function. In your case if the only variant is the URL then you could just pass the URL as the first parameter to get-data. This might seem cumbersome to someone used to OO programming but in functional programming it's quite standard. You might notice when looking at example code, tutorials, open source libraries etc. that almost all code that reads or writes to databases expects the DB connection information (or an entire db object) as a parameter to every single function. Another thing you often see is an entire "env" map being passed around which has all config in it such as endpoint URLs.

      passing state down the call stack configuration, connection, db--pretty common in FP

    2. Something that I've found helps greatly with testing is that when you have code with lots of nested function calls you should try to refactor it into a flat, top level pipeline rather than a calling each function from inside its parent function. Luckily in clojure this is really easy to do with macros like -> and friends, and once you start embracing this approach you can enter a whole new world of transducers. What I mean by a top level pipeline is that for example instead of writing code like this: (defn remap-keys [data] ...some logic...) (defn process-data [data] (remap-keys (flatten data))) (defn get-data [] (let [data (http/get *url*)] (process-data data))) you should make each step its own pure function which receives and returns data, and join them all together at the top with a threading macro: (defn fetch-data [url] (http/get url)) (defn process-data [data] (flatten data)) (defn remap-keys [data] ...some logic...) (defn get-data [] (-> *url* fetch-data process-data remap-keys)) You code hasn't really changed, but now each function can be tested completely independently of the others, because each one is a pure data transform with no internal calls to any of your other functions. You can use the repl to run each step one at a time and in doing so also capture some mock data to use for your tests! Additionally you could make an e2e tests pipeline which runs the same code as get-data but just starts with a different URL, however I would not advise doing this in most cases, and prefer to pass it as a parameter (or at least dynamic var) when feasible.

      testing flat no deep call stacks, use pipelines

    3. One thing Component taught me was to think of the entire system like an Object. Specifically, there is state that needs to be managed. So I suggest you think about -main as initializing your system state. Your system needs an http client, so initialize it before you do anything else

      software design state on the outside, before anything else lessions from Component

    1. Prezi is a productivity platform that allows for creation, organization, collaboration of presentations. It can be used with either mobile or desktop. Prezi integrates with slack and salesforce. RATING: 5/5 (rating based upon a score system 1 to 5, 1= lowest 5=highest in terms of content, veracity, easiness of use etc.)

    1. The Moodle project

      Moodle is one of the largest open source collaborative platform used in the development of curriculum.

      Moodle is an Australian company and has various levels of subscriptions including one level for free. Overall I have found the site to be user friendly rich with demos, documentation and support including community forums. This site supports multiple languages and has an easy to use drop down menu for that selection.

      RATING: 5/5 (rating based upon a score system 1 to 5, 1= lowest 5=highest in terms of content, veracity, easiness of use etc.)