I would like to share an experience which is related to securely storing access keys and billing of AWS cloud account.
6 years back, I have started using AWS Cloud services for one of our project requirements. It was an excitement to start working on the cloud. We started exploring and using different services. For one of the use case, we need to store some documents which should be secure, easily managed, and will be growing as the project feature will grow. We opted for AWS Simple Storage Service.
There is a famous quote by Jim Henson: “If you can’t beat them. Join them”.
It’s possible to write code for years without deliberately using delegates. I say “deliberately” because we may have used them without realizing it. Knowing what these types represent makes reading code easier. Knowing how to use them adds some useful tools to our developer toolbox. So instead of ignoring them, why not learn them. In this post, I will show you how you can get started with delegates and their use cases, which will encourage you to use them more in your code.
(as presented in TechWell Agile and DevOps Virtual Conference 11 November 2020)
Ask a group of engineers how to “DevOps,” and many will say, “Automate all the things!” That’s a great answer and definitely covers many of the DevOps processes, but DevOps is so much more than that. I want to discuss why automation is important, how it relates to DevOps, and when automation may or may not be the right tool for the job.
In traditional software development approaches, releases are spread out and recur at intervals for every small feature update or bug fix. This dramatically increases the chances of changes getting coupled at the time of deployment. Over time, the problem starts to grow, posing more challenges for an entire team. The worst part is that all processes are manual, and most of these products are developed/tested individually. Needless to say, it becomes more prone to human error. CI/CD is something that solves all this and makes the entire process more manageable and efficient.
Continuous Integration/Continuous Deployment or CI/CD is the backbone of building, testing, and deploying applications to production in modern software development practices. CI/CD plays a pivotal role in bridging the gap between development and various affected teams. CI helps to mitigate the risks and enables production parity by automating multiple code changes from varied developers of the project. On the other hand, CD enables developers to deliver the integrated code to production seamlessly, thus providing a quick and effective automated process to release new features and updates to customers without much hassle.
Google has introduced another and upgraded form of recaptcha called Google reCAPTCHA v3. It gives greater protection from the spam bot or maltreatment in your web structures or web forms. Google reCAPTCHA v3 API works on the premise of spam score which implies that the reCAPTCHA v3 API restores the spam score of each input given by the client action.
Benefits of Google reCAPTCHA v3
This reCAPTCHA v3 is exceptionally simple to utilize as compared to Google reCAPTCHA v2 on the grounds that the client doesn't have to click on the checkbox which is in the Google reCAPTCHA v2. It just ascertains the spam score dependent on the information and client's movement and chooses whether it is a spam action or not.
Today I want to share a simple intro animation with you. The concept is to first show an image stack and then animate each image to its position in the grid (or any other layout).
For the first demo, I actually used a simple serial layout and added some smooth scrolling with Locomotive Scroll. The animations are powered by GSAP.
Despite the fact that Apache Zookeeper’s functionalities are not legitimately noticeable to end-client however it remains as the spine for hyped components like Hadoop to oversee automatic failover, Kafka’s broker coordination, Solr, HBase, Apache S4, and some more. Besides, Zookeeper is being extensively utilized for many free software projects like AdroitLogic UltraESB, Akka, GoldenOrb (massive-scale Graph analysis), Neo4j(Graph Database), etc. On top of it, many esteemed companies like Yahoo, Rackspace, Box, Midokura, etc. are using it for their operational purpose.
Before expounding the steps to set up multi-node Zookeeper servers/ cluster, should loosen up my thankfulness to all the thriving gatherings beginning from cleaning/sterile social event to Nurses, Doctors and other who are dependably battling to spare the humankind from constant Covid-19 pandemic over the globe.
You must have heard this word Oauth if you are from a development background. It is because of its popularity, in a few past years technology has evolved a lot and so the security. With increasing concerns of security, a lot of frameworks and patterns came into the picture and Oauth was one of them. When developers started using Oauth, they found it very secure and useful, and with increasing popularity, so many organizations started using this.
Now, you will notice that millions of applications are now powered by the Oauth authorization framework. It's important that you know what it is all about and I think that's why you are reading this article.
Over the past five years, blockchain has gained immense popularity almost from scratch. Although this popularity was somewhat overheated by the hype over Bitcoin, blockchain remains a useful and in-demand technology. Blockchain has already been successfully applied in many fields, including healthcare. In this overview, we will consider the main scenarios for using blockchain technology in healthcare, medicine, and pharmaceuticals.
Pre-Requisites For the Use of Blockchain In Healthcare
Traditional mechanisms for the exchange of medical information are outdated; they no longer cope with their tasks in modern healthcare infrastructure. In some countries, a patient has to personally bring all of their past medical records to the new hospital or undergo the medical tests again.
A web font workflow is simple, right? Choose a few nice-looking web-ready fonts, get the HTML or CSS code snippet, plop it in the project, and check if they display properly. People do this with Google Fonts a zillion times a day, dropping its <link> tag into the <head>.
Let’s see what Lighthouse has to say about this workflow.
Stylesheets in the <head> have been flagged by Lighthouse as render-blocking resources and they add a one-second delay to render? Not great.
We’ve done everything by the book, documentation, and HTML standards, so why is Lighthouse telling us everything is wrong?
Let’s talk about eliminating font stylesheets as a render-blocking resource, and walk through an optimal setup that not only makes Lighthouse happy, but also overcomes the dreaded flash of unstyled text (FOUT) that usually comes with loading fonts. We’ll do all that with vanilla HTML, CSS, and JavaScript, so it can be applied to any tech stack. As a bonus, we’ll also look at a Gatsby implementation as well as a plugin that I’ve developed as a simple drop-in solution for it.
What we mean by “render-blocking” fonts
When the browser loads a website, it creates a render tree from the DOM, i.e. an object model for HTML, and CSSOM, i.e. a map of all CSS selectors. A render tree is a part of a critical render path that represents the steps that the browser goes through to render a page. For browser to render a page, it needs to load and parse the HTML document and every CSS file that is linked in that HTML.
Here’s a fairly typical font stylesheet pulled directly from Google Fonts:
You might be thinking that font stylesheets are tiny in terms of file size because they usually contain, at most, a few @font-face definitions. They shouldn’t have any noticeable effect on rendering, right?
Let’s say we’re loading a CSS font file from an external CDN. When our website loads, the browser needs to wait for that file to load from the CDN and be included in the render tree. Not only that, but it also needs to wait for the font file that is referenced as a URL value in the CSS @font-face definition to be requested and loaded.
Bottom line: The font file becomes a part of the critical render path and it increases the page render delay.
What is the most vital part of any website to the average user? It’s the content, of course. That is why content needs to be displayed to the user as soon as possible in a website loading process. To achieve that, the critical render path needs to be reduced to critical resources (e.g. HTML and critical CSS), with everything else loaded after the page has been rendered, fonts included.
If a user is browsing an unoptimized website on a slow, unreliable connection, they will get annoyed sitting on a blank screen that’s waiting for font files and other critical resources to finish loading. The result? Unless that user is super patient, chances are they’ll just give up and close the window, thinking that the page is not loading at all.
However, if non-critical resources are deferred and the content is displayed as soon as possible, the user will be able to browse the website and ignore any missing presentational styles (like fonts) — that is, if they don’t get in the way of the content.
Optimized websites render content with critical CSS as soon as possible with non-critical resources deferred. A font switch occurs between 0.5s and 1.0s on the second timeline, indicating the time when presentational styles start rendering.
The optimal way to load fonts
There’s no point in reinventing the wheel here. Harry Roberts has already done a great job describing an optimal way to load web fonts. He goes into great detail with thorough research and data from Google Fonts, boiling it all down into a four-step process:
Preconnect to the font file origin.
Preload the font stylesheet asynchronously with low priority.
Asynchronously load the font stylesheet and font file after the content has been rendered with JavaScript.
Provide a fallback font for users with JavaScript turned off.
Let’s implement our font using Harry’s approach:
<!-- https://fonts.gstatic.com is the font file origin -->
<!-- It may not have the same origin as the CSS file (https://fonts.googleapis.com) -->
<link rel="preconnect"
href="https://fonts.gstatic.com"
crossorigin />
<!-- We use the full link to the CSS file in the rest of the tags -->
<link rel="preload"
as="style"
href="https://fonts.googleapis.com/css2?family=Merriweather&display=swap" />
<link rel="stylesheet"
href="https://fonts.googleapis.com/css2?family=Merriweather&display=swap"
media="print" onload="this.media='all'" />
<noscript>
<link rel="stylesheet"
href="https://fonts.googleapis.com/css2?family=Merriweather&display=swap" />
</noscript>
Notice the media="print" on the font stylesheet link. Browsers automatically give print stylesheets a low priority and exclude them as a part of the critical render path. After the print stylesheet has been loaded, an onload event is fired, the media is switched to a default all value, and the font is applied to all media types (screen, print, and speech).
Lighthouse is happy with this approach!
It’s important to note that self-hosting the fonts might also help fix render-blocking issues, but that is not always an option. Using a CDN, for example, might be unavoidable. In some cases, it’s beneficial to let a CDN do the heavy lifting when it comes to serving static resources.
Even though we’re now loading the font stylesheet and font files in the optimal non-render-blocking way, we’ve introduced a minor UX issue…
Flash of unstyled text (FOUT)
This is what we call FOUT:
Why does that happen? To eliminate a render-blocking resource, we have to load it after the page content has rendered (i.e. displayed on the screen). In the case of a low-priority font stylesheet that is loaded asynchronously after critical resources, the user can see the moment the font changes from the fallback font to the downloaded font. Not only that, the page layout might shift, resulting in some elements looking broken until the web font loads.
The best way to deal with FOUT is to make the transition between the fallback font and web font smooth. To achieve that we need to:
Choose a suitable fallback system font that matches the asynchronously loaded font as closely as possible.
Adjust the font styles (font-size, line-height, letter-spacing, etc.) of the fallback font to match the characteristics of the asynchronously loaded font, again, as closely as possible.
Clear the styles for the fallback font once the asynchronously loaded font file has has rendered, and apply the styles intended for the newly loaded font.
We can use Font Style Matcher to find optimal fallback system fonts and configure them for any given web font we plan to use. Once we have styles for both the fallback font and web font ready, we can move on to the next step.
Merriweather is the font and Georgia is the fallback system font in this example. Once the Merriweather styles are applied, there should be minimal layout shifting and the switch between fonts should be less noticeable.
We can use the CSS font loading API to detect when our web font has loaded. Why that? Typekit’s web font loader was once one of the more popular ways to do it and, while it’s tempting to continue using it or similar libraries, we need to consider the following:
It hasn’t been updated for over four years, meaning that if anything breaks on the plugin side or new features are required, it’s likely no one will implement and maintain them.
We are already handling async loading efficiently using Harry Roberts’ snippet and we don’t need to rely on JavaScript to load the font.
If you ask me, using a Typekit-like library is just too much JavaScript for a simple task like this. I want to avoid using any third-party libraries and dependencies, so let’s implement the solution ourselves and try to make it is as simple and straightforward as possible, without over-engineering it.
Although the CSS Font Loading API is considered experimental technology, it has roughly 95% browser support. But regardless, we should provide a fallback if the API changes or is deprecated in the future. The risk of losing a font isn’t worth the trouble.
The CSS Font Loading API can be used to load fonts dynamically and asynchronously. We’ve already decided not to rely on JavaScript for something simple as font loading and we’ve solved it in an optimal way using plain HTML with preload and preconnect. We will use a single function from the API that will help us check if the font is loaded and available.
document.fonts.check("12px 'Merriweather'");
The check() function returns true or false depending on whether the font specified in the function argument is available or not. The font size parameter value is not important for our use case and it can be set to any value. Still, we need to make sure that:
We have at least one HTML element on a page that contains at least one character with web font declaration applied to it. In the examples, we will use the but any character can do the job as long it’s hidden (without using display: none;) from both sighted and non-sighted users. The API tracks DOM elements that have font styles applied to them. If there are no matching elements on a page, then the API isn’t be able to determine if the font has loaded or not.
The specified font in the check() function argument is exactly what the font is called in the CSS.
I’ve implemented the font loading listener using CSS font loading API in the following demo. For example purposes, loading fonts and the listener for it are initiated by clicking the button to simulate a page load so you can see the change occur. On regular projects, this should happen soon after the website has loaded and rendered.
Isn’t that awesome? It took us less than 30 lines of JavaScript to implement a simple font loading listener, thanks to a well-supported function from the CSS Font Loading API. We’ve also handled two possible edge cases in the process:
Something goes wrong with the API, or some error occurs preventing the web font from loading.
The user is browsing the website with JavaScript turned off.
Now that we have a way to detect when the font file has finished loading, we need to add styles to our fallback font to match the web font and see how to handle FOUT more effectively.
The transition between the fallback font and web font looks smooth and we’ve managed to achieve a much less noticeable FOUT! On a complex site, this change would result in a fewer layout shifts, and elements that depend on the content size wouldn’t look broken or out of place.
What’s happening under the hood
Let’s take a closer look at the code from the previous example, starting with the HTML. We have the snippet in the <head> element, allowing us to load the font asynchronously with preload, preconnect, and fallback.
<body class="no-js">
<!-- ... Website content ... -->
<div aria-visibility="hidden" class="hidden" style="font-family: '[web-font-name]'">
/* There is a non-breaking space here here */
</div>
<script>
document.getElementsByTagName("body")[0].classList.remove("no-js");
</script>
</body>
Notice that we have a hardcoded .no-js class on the <body> element, which is removed the moment the HTML document has finished loading. This applies webfont styles for users with JavaScript disabled.
Secondly, remember how the CSS Font Loading API requires at least one HTML element with a single character to track the font and apply its styles? We added a <div> with a character that we are hiding from both sighted and non-sighted users in an accessible way, since we cannot use display: none;. This element has an inlined font-family: 'Merriweather' style. This allows us to smoothly switch between the fallback styles and loaded font styles, and make sure that all font files are properly tracked, regardless of whether they are used on the page or not.
Note that the character is not showing up in the code snippet but it is there!
The CSS is the most straightforward part. We can utilize the CSS classes that are hardcoded in the HTML or applied conditionally with JavaScript to handle various font loading states.
JavaScript is where the magic happens. As described previously, we are checking if the font has been loaded by using the CSS Font Loading API’s check() function. Again, the font size parameter can be any value (in pixels); it’s the font family value that needs to match the name of the font that we’re loading.
var interval = null;
function fontLoadListener() {
var hasLoaded = false;
try {
hasLoaded = document.fonts.check('12px "[web-font-name]"')
} catch(error) {
console.info("CSS font loading API error", error);
fontLoadedSuccess();
return;
}
if(hasLoaded) {
fontLoadedSuccess();
}
}
function fontLoadedSuccess() {
if(interval) {
clearInterval(interval);
}
/* Apply class names */
}
interval = setInterval(fontLoadListener, 500);
What’s happening here is we’re setting up our listener with fontLoadListener() that runs at regular intervals. This function should be as simple as possible so it runs efficiently within the interval. We are using the try-catch block to handle any errors and catch any issues so that web font styles still apply in the case of a JavaScript error so that the user doesn’t experience any UI issues.
Next, we’re accounting for when the font successfully loads with fontLoadedSuccess(). We need to make sure to first clear the interval so the check doesn’t unnecessarily run after it. Here we can add class names that we need in order to apply the web font styles.
And, finally, we are initiating the interval. In this example, we’ve set it up to 500ms, so the function runs twice per second.
Here’s a Gatsby implementation
Gatsby does a few things that are different compared to vanilla web development (and even the regular create-react-app tech stack) which makes implementing what we’ve covered here a bit tricky.
To make this easy, we’ll develop a local Gatsby plugin, so all code that is relevant to our font loader is located at plugins/gatsby-font-loader in the example below.
Our font loader code and config will be split across the three main Gatsby files:
Plugin configuration (gatsby-config.js): We’ll include the local plugin in our project, list all local and external fonts and their properties (including the font name, and the CSS file URL), and include all preconnect URLs.
Server-side code (gatsby-ssr.js): We’ll use the config to generate and include preload and preconnect tags in the HTML <head> using setHeadComponents function from Gatsby’s API. Then, we’ll generate the HTML snippets that hide the font and include them in HTML using setPostBodyComponents.
Client-side code (gatsby-browser.js): Since this code runs after the page has loaded and after React starts up, it is already asynchronous. That means we can inject the font stylesheet links using react-helmet. We’ll also start a font loading listener to deal with FOUT.
You can check out the Gatsby implementation in the following CodeSandbox example.
I know, some of this stuff is complex. If you just want a simple drop-in solution for performant, asynchronous font loading and FOUT busting, I’ve developed a gatsby-omni-font-loader plugin just for that. It uses the code from this article and I am actively maintaining it. If you have any suggestions, bug reports, or code contributions, feel free to submit them on on GitHub.
Conclusion
Content is perhaps the most component to a user’s experience on a website. We need to make sure content gets top priority and loads as quickly as possible. That means using bare minimum presentation styles (i.e. inlined critical CSS) in the loading process. That is also why web fonts are considered non-critical in most cases — the user can still consume the content without them — so it’s perfectly fine for them to load after the page has rendered.
But that might lead to FOUT and layout shifts, so the font loading listener is needed to make a smooth switch between the fallback system font and the web font.
I’d like to hear your thoughts! Let me know in the comments how are you tackling the issue of web font loading, render-blocking resources and FOUT on your projects.
my excitement for Core Web Vitals is tempered with a healthy skepticism. I’m not yet convinced that Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS) are the right metrics that all sites should be measuring themselves against. I worry that the outsized emphasis placed on Core Web Vitals by including them in SEO scoring will result in developers focusing solely on those three numbers without truly understanding what they mean and, more importantly, what they don’t mean.
Katie is pro-Web Core Vitals because of their correlation with real user experiences, but there is a lot more to think about. If we focus only on these metrics (because we have now an extremely strong incentive to do so) we’re missing out on a lot. They may not be the analytics that matter most to us or that correlate with business goals.
The horse’s mouth says the SEO implications don’t start until May 2021.
I admit I’ve been on the hype train myself a little bit. I like all of Katie’s points but I think I’ll still call it a step forward for web analytics. Robin also mentioned Sentry could do the tracking the other day.
Personally, my beef with core web vitals is that they introduce even more uneccessary initialisms (see, for example, Harry’s recent post where he uses CWV metrics like LCP, FID, and CLS—alongside TTFB and SI—to look at PLPs, PDPs, and SRPs. I mean, WTF?).
COVID is changing the way the world works. As opposed to being tethered to a desk for 40 hours a week, many companies have adopted a work from home policy for the time being. And some for the unforeseeable future.
Hi All! Today I want to show a quick’n’dirty way to easily deploy your projects to Azure using Powershell.
I’ve been working a lot recently with Azure Functions and Web Apps. And of course, each time I’m confident with my code, I want to see it deployed on the Cloud.
In today’s technologically connected world, a programmer’s success would be highly dependent on their decision to keep learning and adapting to innovation. Even if you’ve been a programmer for a while now, you surely know that looking for skills improvement opportunities is significant.
Whether you are new or seasoned in the world of programming, you can surely benefit from these seven tips.
Hi All! With this post, we’ll start a new Series about Event Sourcing on Azure. We’re going to talk a bit about the pattern, general architecture, and the individual building blocks. Then in the next posts, we’ll dig more and see each one in detail.
If you’re a regular reader of this blog, you might know that I wrote already about Event Sourcing in the past. It’s a complex pattern, probably one of the most complex to get right. I enjoy the challenges it gives and how it causes a whole plethora of other patterns to be evaluated in conjunction (CQRS anyone?).
