Javascript

How to Contribute to RxJS

Published Feb 10, 2022

Updated Jan 30, 2023

3 min read

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

This Dot Media is kicking off a brand new series of videos in 2022 to help developers learn how they can contribute code to some of the world’s most popular JavaScript frameworks and technologies. Subscribe to This Dot Media’s Youtube Channel.

To continue our series, highlighting best practices for developers interested in contributing to their favorite technologies, I met up with my good friend and creator of RxJS, Ben Lesh. If you would like to check out that interview, you can see it here.

What is RxJS?

RxJS is a library for reactive programming that uses Observables to make it easier to compose asynchronous or callback-based code.

It is a rewrite of Reactive-Extensions/RxJS with better performance, better modularity, better debuggable call stacks, all while staying mostly backwards compatible, with some breaking changes that reduce the API surface.

Ben Lesh

Ben Lesh is an international speaker and RxJS Core Team Member. His involvement with the framework started a few years ago, when he was asked to work on a rewrite due to his open-source experience in other projects at Netflix.

What to Know Before You Get Started

According to Ben, the codeofconduct.md and contributing.md documents are the best places for new developers to start. It is crucial that new contributors abide by community standards and the correct commit format, so be sure to read through!

Quick Tips!

-Everything in RxJS is written under src/internal, where you can look at all the internals of RxJS. -The commit message generates the changelog, which can be found on changelog.md.

The Best Way to Get Started

When I asked Ben what areas of the repository were best for new contributors, and what areas needed the most attention, he of course said: documentation.

But it’s true! According to Ben, devs can simply click the “Improve Documentation” button, and do a direct commit.

Presently, the team could significantly benefit from contributors interested in checking links to ensure that they are not broken, revising grammatical errors, ensuring all information is up to date, and adding edit buttons in the documentation for individual pages.

However, if developers are looking for a different challenge, they can see open requests for contribution by checking out the “help wanted” tag in the issues section.

Quick Tips! -Don’t simply submit a bunch of PRs to get on the contributors list! Focus on contributing helpful, meaningful work that will advance RxJS! -Because issues are not checked every day, you want to make sure that there is not already a PR for it, and that it hasn’t already been assigned to someone. Also, make sure to look through the PRs to ensure that the issue is not being addressed in both open and closed PRs.

What About Attending Core Team Meetings?

Core Team meetings typically address in-depth issues and questions related to RxJS, and are not open to the public. However, contributors can receive invitations based on their PRs and need, so if developers are interested in attending Core Team meetings, the best thing to do is create a presence in the RxJS Community!

Though meetings aren’t open or recorded, community members can view the issues, and see the tag “agenda item” to see what topics will be addressed at upcoming meetings. Usually, the discussions are commented on in the issues.

Quick Tips! -If you are interested in getting involved, but don’t want to contribute code, go out into the world and review external articles or Stack Overflow, and help in the community! -Blog posts and explanations about RxJS are also valued by the community and Core Team!

Ready to Begin?

You can find the RxJS repository here!

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About the author(s)

Tracy Lee
Partner, This Dot Google Developer Expert (Angular, TC39, Web) RxJS Core Team & Lead for RxJS Learning Team Contributor to Angular, RxJS, EmberJS

Key Strengths:
- Teaching developer relations strategies
- Influencer marketing
- Developing brands
- Community strategies and maintenance
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@ladyleet @ladyleet

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The HTML Dialog Element: Enhancing Accessibility and Ease of Use

The HTML Dialog Element: Enhancing Accessibility and Ease of Use Dialogs are a common component added to applications, whether on the web or in native applications. Traditionally there has not been a standard way of implementing these on the web, resulting in many ad-hoc implementations that don’t act consistently across different web applications. Often, commonly expected features are missing from dialogs due to the complexity of implementing them. However, web browsers now offer a standard dialog element. Why use the dialog element? The native dialog element streamlines the implementation of dialogs, modals, and other kinds of non-modal dialogs. It does this by implementing many of the features needed by dialogs for you that are already baked into the browser. This is helpful as it reduces the burden on the developer when making their applications accessible by ensuring that user expectations concerning interaction are met, and it can also potentially simplify the implementation of dialogs in general. Basic usage Adding a dialog using the new tag can be achieved with just a few lines of code. ` However, adding the dialog alone won’t do anything to the page. It will show up only once you call the .showModal() method against it. ` Then if you want to close it you can call the .close() method on the dialog, or press the escape key to close it, just like most other modals work. Also, note how a backdrop appears that darkens the rest of the page and prevents you from interacting with it. Neat! Accessibility and focus management Correctly handling focus is important when making your web applications accessible to all users. Typically you have to move the current focus to the active dialog when showing them, but with the dialog element that’s done for you. By default, the focus will be set on the first focusable element in the dialog. You can optionally change which element receives focus first by setting the autofocus attribute on the element you want the focus to start on, as seen in the previous example where that attribute was added to the close element. Using the .showModal() method to open the dialog also implicitly adds the dialog ARIA role to the dialog element. This helps screen readers understand that a modal has appeared and the screen so it can act accordingly. Adding forms to dialogs Forms can also be added to dialogs, and there’s even a special method value for them. If you add a element with the method set to dialog then the form will have some different behaviors that differ from the standard get and post form methods. First off, no external HTTP request will be made with this new method. What will happen instead is that when the form gets submitted, the returnValue property on the form element will be set to the value of the submit button in the form. So given this example form: ` The form element with the example-form id will have its returnValue set to Submit. In addition to that, the dialog will close immediately after the submit event is done being handled, though not before automatic form validation is done. If this fails then the invalid event will be emitted. You may have already noticed one caveat to all of this. You might not want the form to close automatically when the submit handler is done running. If you perform an asynchronous request with an API or server you may want to wait for a response and show any errors that occur before dismissing the dialog. In this case, you can call event.preventDefault() in the submit event listener like so: ` Once your desired response comes back from the server, you can close it manually by using the .close() method on the dialog. Enhancing the backdrop The backdrop behind the dialog is a mostly translucent gray background by default. However, that backdrop is fully customizable using the ::backdrop pseudo-element. With it, you can set a background-color to any value you want, including gradients, images, etc. You may also want to make clicking the backdrop dismiss the modal, as this is a commonly implemented feature of them. By default, the <dialog> element doesn’t do this for us. There are a couple of changes that we can make to the dialog to get this working. First, an event listener is needed so that we know when the user clicks away from the dialog. ` Alone this event listener looks strange. It appears to dismiss the dialog whenever the dialog is clicked, not the backdrop. That’s the opposite of what we want to do. Unfortunately, you cannot listen for a click event on the backdrop as it is considered to be part of the dialog itself. Adding this event listener by itself will effectively make clicking anywhere on the page dismiss the dialog. To correct for this we need to wrap the contents of the dialog content with another element that will effectively mask the dialog and receive the click instead. A simple element can do! ` Even this isn’t perfect though as the contents of the div may have elements with margins in them that will push the div down, resulting in clicks close to the edges of the dialog to dismiss it. This can be resolved by adding a couple of styles the the wrapping div that will make the margin stay contained within the wrapper element. The dialog element itself also has some default padding that will exacerbate this issue. ` The wrapping div can be made into an inline-block element to contain the margin, and by moving the padding from the parent dialog to the wrapper, clicks made in the padded portions of the dialog will now interact with the wrapper element instead ensuring it won’t be dismissed. Conclusion Using the dialog element offers significant advantages for creating dialogs and modals by simplifying implementation with reasonable default behavior, enhancing accessibility for users that need assistive technologies such as screen readers by using automatic ARIA role assignment, tailored support for form elements, and flexible styling options....

Oct 25, 2024

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HTMLJavaScript

Intro to DevRel: What's the Difference Between External and Internal DevRel Programs?

Developer Relations (DevRel) is a proactive, multifaceted discipline that bridges the gap between developers and companies to drive adoption while cultivating an energetic and supportive developer community for their product, service, or technology. The term and the profession are often misunderstood even among those in other technical roles. Some have never heard of DevRel before, and others believe it’s a kind of tech support for developers. Many organizations even think starting a DevRel program means just giving away free software and hoping it catches on. But DevRel is none of these things. At its core, a successful DevRel program builds strong bonds within their target market to ensure that developers can interface with a company or organization behind the product they’re using. Great teams establish authentic connections with developers, cultivate trust, and actively engage with them. DevRel defies traditional marketing strategies. Instead of prioritizing numbers and eyes that contribute to a sales funnel, it focuses on enhancing developer satisfaction. This creates a feedback loop between users and a company to better meet their needs, and foster a sense of collaboration within a product’s user community. The Two Main Domains of Developer Relations DevRel is split into 2 main domains: external and internal. External: Accessing an existing developer community If a company already has a product with an existing community or a product that may appeal to an existing community, and they want to establish a DevRel program around it, this would fall within the external domain. A successful external program will establish credibility and support developers through a number of evangelistic measures like blog posts, tutorials, webinars, giving talks at meetups and conferences, or creating useful code examples to teach concepts. These activities and their goals are rarely product-specific. Instead, they incorporate a number of technologies within their product’s technical ecosystem to demonstrate its value to a developer’s workflow. I had the pleasure of working with Doron Sherman during his tenure at Cloudinary as VP of Developer Relations. Doron has extensive experience with building developer communities, and successfully advocated internally to build a website called Media Jams, a learning resource for developers working with media in their apps. By having this initiative live under Developer Relations, and not under Product, Marketing, or Engineering, Doron and his team built quickly and created a site that prioritized education, without needing to meet the business objectives of other parts of the organization. > “Media Jams has had great organic growth as a community resource. We were able to attract non-Cloudinary users as well as organic search traffic of those looking for media use cases who would have otherwise gotten lost in the Cloudinary docs and/or could not find help through the Cloudinary blog or knowledge base.” says Doron. Internal: Building a developer community In order to support the adoption and retention of developers using a product, companies must have a space where developers can interface with them. Building their own community around a product is the best way to do this. By creating open lines of communication, developers can provide immediate feedback about a product in a productive way to product and engineering teams thereby shortening the feedback loop and improving the speed at which a team is able to innovate based on user needs. This strategy falls under the internal domain. These forums also provide synergistic opportunities for developers that are using a product to learn from each other. By working on similar problems, developers are able to bond and feel more ownership or excitement toward a product, increasing user retention. Danny Thompson, a developer influencer and mentor who has built a community of over a quarter million followers, says that he admires Appwrite’s DevRel program, helmed by Tessa Mero, Head of Developer Relations: > “The Appwrite DevRel team is great at answering questions. They are on Discord, jumping on calls with developers, answering questions, and doing office hours, all of which are super valuable in building that community. The main difference between Appwrite DevRel and other teams is, a lot of communities are run very passively and not always available or taking an active approach within community forums to help out.” - Danny Thompson on Appwrite. > “When we think about how to become successful as a company through DevRel, our first consideration is, what made us successful in the first place? Appwrite became an open-source company and a successful open-source project because of community, so we focus on a community-first approach. Contributors and developers that have supported us since before we were a company are what led us to where we are now. Every initiative, every planning, and everything we do on our team, we consider the community's feedback and perspective before we make any decisions.” - Tessa Mero at Appwrite. The Value-First Approach to Developer Relations Successful DevRel programs prioritize delivering value to cultivate credibility among developers and support product adoption free from reciprocal demands. External efforts involve engaging with existing technology communities, establishing credibility through various evangelistic measures, and delivering value to the community. On the other hand, internal programs build communities around their product, facilitating direct communication between developers and the company. These internal forums not only enhance user retention but also foster a space for developers to learn from each other, creating a sense of ownership and excitement around the product. And by diverting equity to these two programs, DevRel teams find new users, retain them, and receive invaluable feedback. Real-world examples, such as Doron Sherman's work at Cloudinary and Tessa Mero's leadership at Appwrite, showcase the effectiveness of DevRel in action, and highlight how DevRel programs contribute to the success and sustainability of developer-focused products. In the ever-evolving landscape of technology, DevRel emerges not only as a bridge between developers and organizations, but as a crucial driver of innovation, ensuring products remain relevant, adaptive, and deeply integrated into the communities they serve. If you’re thinking about building a successful DevRel program for the first time, the best place to start is to reflect on some of your favorite brands and how they connect with the developer community. Do they simply distribute discount codes and free swag, or are they reaching out to their users, and providing them a platform to learn, collaborate with others, and contribute? If they are, what methods do they use, and how do those methods coincide with your team’s existing strengths? And if you ever have any questions or want to connect with a DevRel specialist, do not hesitate to reach out!...

Nov 22, 2023

5 mins

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Introduction to Zod for Data Validation

As web developers, we're often working with data from external sources like APIs we don't control or user inputs submitted to our backends. We can't always rely on this data to take the form we expect, and we can encounter unexpected errors when it deviates from expectations. But with the Zod library, we can define what our data ought to look like and parse the incoming data against those defined schemas. This lets us work with that data confidently, or to quickly throw an error when it isn't correct. Why use Zod? TypeScript is great for letting us define the shape of our data in our code. It helps us write more correct code the first time around by warning us if we are doing something we shouldn't. But TypeScript can't do everything for us. For example, we can define a variable as a string or a number, but we can't say "a string that starts with user_id_ and is 20 characters long" or "an integer between 1 and 5". There are limits to how much TypeScript can narrow down our data for us. Also, TypeScript is a tool for us developers. When we compile our code, our types are not available to the vanilla JavaScript. JavaScript can't validate that the data we actually use in our code matches what we thought we'd get when we wrote our TypeScript types unless you're willing to manually write code to perform those checks. This is where we can reach for a tool like Zod. With Zod, we can write data schemas. These schemas, in the simplest scenarios, look very much like TypeScript types. But we can do more with Zod than we can with TypeScript alone. Zod schemas let us create additional rules for data parsing and validation. A 20-character string that starts with user_id_? It's z.string().startsWith('user_id_').length(20). An integer between 1 and 5 inclusive? It's z.number().int().gte(1).lte(5). Zod's primitives give us many extra functions to be more specific about *exactly* what data we expect. Unlike TypeScript, Zod schemas aren't removed on compilation to JavaScript—we still have access to them! If our app receives some data, we can verify that it matches the expected shape by passing it to your Zod schema's parse function. You'll either get back your data in exactly the shape you defined in your schema, or Zod will give you an error to tell you what was wrong. Zod schemas aren't a replacement for TypeScript; rather, they are an excellent complement. Once we've defined our Zod schema, it's simple to derive a TypeScript type from it and to use that type as we normally would. But when we really need to be sure our data conforms to the schema, we can always parse the data with our schema for that extra confidence. Defining Data Schemas Zod schemas are the variables that define our expectations for the shape of our data, validate those expectations, and transform the data if necessary to match our desired shape. It's easy to start with simple schemas, and to add complexity as required. Zod provides different functions that represent data structures and related validation options, which can be combined to create larger schemas. In many cases, you'll probably be building a schema for a data object with properties of some primitive type. For example, here's a schema that would validate a JavaScript object representing an order for a pizza: ` Zod provides a number of primitives for defining schemas that line up with JavaScript primitives: string, number, bigint, boolean, date, symbol, undefined, and null. It also includes primitives void, any, unknown, and never for additional typing information. In addition to basic primitives, Zod can define object, array, and other native data structure schemas, as well as schemas for data structures not natively part of JavaScript like tuple and enum. The documentation contains considerable detail on the available data structures and how to use them. Parsing and Validating Data with Schemas With Zod schemas, you're not only telling your program what data should look like; you're also creating the tools to easily verify that the incoming data matches the schema definitions. This is where Zod really shines, as it greatly simplifies the process of validating data like user inputs or third party API responses. Let's say you're writing a website form to register new users. At a minimum, you'll need to make sure the new user's email address is a valid email address. For a password, we'll ask for something at least 8 characters long and including one letter, one number, and one special character. (Yes, this is not really the best way to write strong passwords; but for the sake of showing off how Zod works, we're going with it.) We'll also ask the user to confirm their password by typing it twice. First, let's create a Zod schema to model these inputs: ` So far, this schema is pretty basic. It's only making sure that whatever the user types as an email is an email, and it's checking that the password is at least 8 characters long. But it is *not* checking if password and confirmPassword match, nor checking for the complexity requirements. Let's enhance our schema to fix that! ` By adding refine with a custom validation function, we have been able to verify that the passwords match. If they don't, parsing will give us an error to let us know that the data was invalid. We can also chain refine functions to add checks for our password complexity rules: ` Here we've chained multiple refine functions. You could alternatively use superRefine, which gives you even more fine grained control. Now that we've built out our schema and added refinements for extra validation, we can parse some user inputs. Let's see two test cases: one that's bound to fail, and one that will succeed. ` There are two main ways we can use our schema to validate our data: parse and safeParse. The main difference is that parse will throw an error if validation fails, while safeParse will return an object with a success property of either true or false, and either a data property with your parsed data or an error property with the details of a ZodError explaining why the parsing failed. In the case of our example data, userInput2 will parse just fine and return the data for you to use. But userInput1 will create a ZodError listing all of the ways it has failed validation. ` ` We can use these error messages to communicate to the user how they need to fix their form inputs if validation fails. Each error in the list describes the validation failure and gives us a human readable message to go with it. You'll notice that the validation errors for checking for a valid email and for checking password length have a lot of details, but we've got three items at the end of the error list that don't really tell us anything useful: just a custom error of Invalid input. The first is from our refine checking if the passwords match, and the second two are from our refine functions checking for password complexity (numbers and special characters). Let's modify our refine functions so that these errors are useful! We'll add our own error parameters to customize the message we get back and the path to the data that failed validation. ` Now, our error messages from failures in refine are informative! You can figure out which form fields aren't validating from the path, and then display the messages next to form fields to let the user know how to remedy the error. ` By giving our refine checks a custom path and message, we can make better use of the returned errors. In this case, we can highlight specific problem form fields for the user and give them the message about what is wrong. Integrating with TypeScript Integrating Zod with TypeScript is very easy. Using z.infer<typeof YourSchema> will allow you to avoid writing extra TypeScript types that merely reflect the intent of your Zod schemas. You can create a type from any Zod schema like so: ` Using a TypeScript type derived from a Zod schema does *not* give you any extra level of data validation at the type level beyond what TypeScript is capable of. If you create a type from z.string.min(3).max(20), the TypeScript type will still just be string. And when compiled to JavaScript, even that will be gone! That's why you still need to use parse/safeParse on incoming data to validate it before proceeding as if it really does match your requirements. A common pattern with inferring types from Zod schemas is to use the same name for both. Because the schema is a variable, there's no name conflict if the type uses the same name. However, I find that this can lead to confusing situations when trying to import one or the other—my personal preference is to name the Zod schema with Schema at the end to make it clear which is which. Conclusion Zod is an excellent tool for easily and confidently asserting that the data you're working with is exactly the sort of data you were expecting. It gives us the ability to assert at runtime that we've got what we wanted, and allows us to then craft strategies to handle what happens if that data is wrong. Combined with the ability to infer TypeScript types from Zod schemas, it lets us write and run more reliable code with greater confidence....

Nov 15, 2024

7 mins

JavaScriptZod

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Whether it's modernization or custom software solutions, our team of experts can guide you through best practices and how to build scalable, performant software that lasts.

How to Contribute to RxJS

Tracy Lee

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