Post pobrano z: Making a Realistic Glass Effect with SVG

I’m in love with SVG. Sure, the code can look dense and difficult at first, but you’ll see the beauty in the results when you get to know it. The bonus is that those results are in code, so it can be hooked up to a CMS. Your designers can rest easy knowing they don’t have to reproduce an effect for every article or product on your site.

Today I would like to show you how I came up with this glass text effect.

Step 0: Patience and space

SVG can be a lot to take on, especially when you’re just starting to learn it (and if you are, Chris’ book is a good place to start). It’s practically a whole new language and, especially for people who lack design chops, there are lots of new techniques and considerations to know about. Like HTML, though, you’ll find there are a handful of tools that we can reach for to help make SVG much easier to grasp., so be patient and keep trying!

Also, give yourself space. Literally. SVG code is dense so I like to use two or three new lines to space things out. It makes the code easier to read and helps me see how different pieces are separated with less visual distraction. Oh, and use comments to mark where you are in the document, too. That can help organize your thoughts and document your findings.

I’ve made demos for each step we’re going to cover in the process of learning this glass effect as a way to help solidify the things we’re covering as we go.

OK, now that we’re mentally prepared, let’s get into the meat of it!

Step 1: Get the basic image in place

First things first: we need an image as the backdrop for our glass effect. Here we have an <svg> element and an <image> within it. This is similar to adding an <img> in HTML. You’ll notice the dimensions of the viewBox attribute and <image> element in the SVG element are the same. This ensures that the <image> is exactly the same size as the actual picture we’re linking to.

That’s a key distinction to note: we’re linking to an image. The SVG file itself does not draw a raster image, but we can reference one in the SVG code and make sure that asset is in the location we point to. If you’ve worked with Adobe InDesign before, it’s a lot like linking to an image asset in a layout — the image is in the InDesign layout, but the asset itself actually lives somewhere else.

See the Pen
SVG Glass Text Effect – basic image in place by David Fitzgibbon (@loficodes)
on CodePen.

Step 2: Distort the image

Straightforward so far, but this is where things get complicated because we’re going to add a filter to the image we just inserted. This filter is going to distort the image. If you look closely at the difference between the demo in the last step and the one in this step, you’ll see that the edges of objects in the image are a little rough and wavy. That’s the filter at work!

First, we create another <svg> to hold filter. This means that if we ever want to reuse our filter — for example on multiple elements on the page — then we totally can!

Our first filter (#displacement) is going to distort our image. We’re going to use feTurbulence and feDisplacementMap, each explained by Sara Soueidan much better than I can in this post. Beau Jackson also wrote up a nice piece that shows how they can be used to make a cloud effect. Suffice to say, these two filters tend to go together and I like to think of them as when something needs to appear „wobbly.”

With our filter container in place, we just need to apply that filter to our image with a filter attribute on the <image>, magic!

<svg>

  <!-- more stuff -->
  
  <!-- DISTORTION IMAGE: clipped -->
  <image xlink:href="https://s3-us-west-2.amazonaws.com/s.cdpn.io/5946/kyoto.jpg" width="1890" x=0 height="1260" y=0 clip-path="url(#clip)" filter= "url(#distortion)"></image>
  
  <!-- FILTER: wobbly effect -->
  <filter id="distortion">
    <feTurbulence type="turbulence" baseFrequency="0.05" numOctaves="2" result="turbulence"/>
    <feDisplacementMap in2="turbulence" in="SourceGraphic" scale="20" xChannelSelector="R" yChannelSelector="G"/>
  </filter>

  <!-- more stuff -->

</svg>

See the Pen
SVG Glass Text Effect – image distorted by David Fitzgibbon (@loficodes)
on CodePen.

Step 3: Clip the text

We don’t want the entire image to be distorted though. We’re going to clip the shape of our distorted <image> to the shape of some text. This will essentially be the portion of the picture seen „through” the glass.

To do this, we need to add a <text> element in a <clip-path> and give it an id. Calling this id in the clip-path of our <image> now restricts its shape to that of our <text>. Wonderful!

See the Pen
SVG Glass Text Effect – text clipped by David Fitzgibbon (@loficodes)
on CodePen.

Step 4: Reveal the full image

OK, so it’s bueno that we have the distorted <image> clipped to the <text>, but now the rest of the image is gone. No bueno.

We can counteract this by adding a copy of the same <image> but without the clip-path or filter attributes before our existing <image>. This is where I like to add some nice comments to keep things neat. The idea is like placing a transparent layer over what we have so far.

I know, I know, this isn’t very neat, and we’re repeating ourselves. Ideally, we would set our filter straight on the <text> element and use the in="BackgroundImage property for feDisplacementMap to warp what’s behind the text, without the need for extra elements. Unfortunately, this has poor browser support, so we’re going to go with multiple images.

<svg>

  <!-- more stuff -->

  <!-- BACKGROUND IMAGE - visible -->
  <image xlink:href="https://s3-us-west-2.amazonaws.com/s.cdpn.io/5946/kyoto.jpg" width="1890" x=0 height="1260" y=0 ></image>
          
  <!-- DISTORTION IMAGE - clipped -->
  <image xlink:href="https://s3-us-west-2.amazonaws.com/s.cdpn.io/5946/kyoto.jpg" width="1890" x=0 height="1260" y=0 clip-path="url(#clip)" filter= "url(#distortion)"></image>

  <!-- more stuff -->

</svg>

See the Pen
SVG Glass Text Effect – warp complete by David Fitzgibbon (@loficodes)
on CodePen.

Step 5: Place the text… again

Next, we’re going to duplicate our text just as we did for the image in the last step. Unfortunately, because the text is in a clip-path, it’s now not available for rendering. This is the last time we’re going to duplicate content like this, I promise!

Now we should have something that looks like a normal image with black text over it. If the distortion filter on the <image> we’ve already made is what we can see „through” the glass, then our new <text> is going to be the glass itself.

<svg>

  <!-- more stuff -->

  <!-- TEXT - clipped -->
  <clipPath id="clip">
    <text x="50%" y ="50%" dominant-baseline="middle" text-anchor="middle">KYOTO</text>
  </clipPath>
        
  <!-- TEXT - visible -->
  <text x="50%" y ="50%" dominant-baseline="middle" text-anchor="middle">KYOTO</text>

<!-- more stuff -->

</svg>

See the Pen
SVG Glass Text Effect – text in place again by David Fitzgibbon (@loficodes)
on CodePen.

Step 6: Creating the dark edge of the text

This is where things start to get exciting, at least for me! 🤓

We want to create a dark edge along the text element which, when paired with a light edge (we’ll look at that next), will add depth to the appearance of the text against the image.

We want a new filter for our <text>, so let’s create one in our filter’s SVG element and give it an id="textFilter and link it to the filter attribute of the <text> element.

SVG works from the background to the foreground, so the first thing we’re going put in our filter is the shadow that the glass would have, as that is furthest back. I’m gonna level with you, this one is pretty complex, but we’re going to go through it one step at a time.

For this effect, we’re using four filter primitives: feMorphology, feOffset, feFlood and feComposite.

feMorphology is first. We’re using this to make the text fatter. In the demo below, comment out the next three primitives ( feOffset, feFlood, feComposite ) and play with it. I have the value radius="4" to achieve the glass effect, but see what happens if you set it to 1… or 100!

feOffset is used to move all the „pixels” in the previous primitive ( feMorphology ) across the x- or y-axis. The values dx="5" and dy="5" move the „pixels” right on the x-axis and y-axis, respectively. The higher the number, the further they move. Put in negative numbers for dx and the „pixels” will move left. Negative dy and they’ll move up! Again, the is the sort of thing you start to learn as you play around with them.

The reason I have quotes around „pixels” is because they’re not screen pixels like you might expect in CSS. Rather, they refer to the dimensions we set on the parent <svg>. I think of them as percentages. We have used these settings viewBox="0 0 1890 1260" in our example. This means our <svg> is 1890 „pixels” wide. If we set dx="189" it means we’ll move our element 10% of the way across the SVG (1890 divided by 189).

feFlood is great. If you want to fill the screen with color, this is the primitive you need! You might wonder why we can’t read our text now when we apply it. That’s because you can only see the result of the last filter primitive that was created. The result of each of the previous primitives was related to our <text> element. The result of feFlood is just like its name: a flood of color. It doesn’t know what you did before and it doesn’t care — it’s merely going to fill an area with color.

This is where some people start getting frustrated with SVG. It’s hard to work on something when you can’t see it! Trust me, as you work with SVG more you’ll get used to this. In fact, the next few steps will need us to rely on this and trust that everything is still in place.

feComposite is going to solve this issue for us. What does it do? MDN describes it as:

The SVG filter primitive performs the combination of two input images pixel-wise in image space using one of the Porter-Duff compositing operations: over, in, atop, out, xor, and lighter.

That to me is jibba-jabba. I think of it as affecting the alpha layer of in with the color/alpha of in2.

With this in place we can once again see our text spelled out and, because the color we used is slightly transparent, we can even see the distorted „glass” effect coming through. Great!

<svg>

  <!-- more stuff -->
    
  <!-- dark edge -->
  <feMorphology operator="dilate" radius="4" in="SourceAlpha" result="dark_edge_01" />
    <feConvolveMatrix order="3,3" kernelMatrix=
      "1 0 0 
      0 1 0
      0 0 1" in="dark_edge_01" result="dark_edge_02" />
    <feOffset dx="5" dy="5" in="dark_edge_02" result="dark_edge_03"/>
    <feFlood flood-color="rgba(0,0,0,.5)" result="dark_edge_04" />
    <feComposite in="dark_edge_04" in2="dark_edge_03" operator="in" result="dark_edge" />
    
  </filter>

  <!-- more stuff -->

</svg>

See the Pen
SVG Glass Text Effect – dark edge by David Fitzgibbon (@loficodes)
on CodePen.

Step 7: Let’s do the light edge

This is essentially the same as what we literally just did, but we’re going to shift the shape up and to the left using negative dx/dy values. We’re also setting a slightly white color this time. We’re aiming for a nice depth effect.

We’re again in a position where what we can see is the most recent result from a filter primitive, but we can’t see our dark edge! feComposite isn’t what we want to use to bring them together because we don’t want the alpha of the dark edge colored by the light edge… we want to see both! Which leads us to…

<svg>
  <filter id="textFilter">

    <!-- more stuff -->

      <feMorphology operator="dilate" radius="4" in="SourceAlpha" result="light_edge_01" />
      <feConvolveMatrix order="3,3" kernelMatrix=
      "1 0 0 
        0 1 0
        0 0 1" in="light_edge_01" result="light_edge_02" />
      <feOffset dx="-2" dy="-2" in="light_edge_02" result="light_edge_03"/>
      <feFlood flood-color="rgba(255,255,255,.5)" result="light_edge_04" />
      <feComposite in="light_edge_04" in2="light_edge_03" operator="in" result="light_edge" />

    <!-- more stuff -->
  
  </filter>
</svg>

See the Pen
SVG Glass Text Effect – light edge by David Fitzgibbon (@loficodes)
on CodePen.

Step 8: Combine the edges

feMerge! It’s a hero. It lets us take any number of primitive results and merge them, making a new image. Woohoo, we can now see both dark and light edges together!

However, we do want them to be edges rather than both filling up the entire text, so we need to remove the space that the original <text> takes up. What we need next is another feComposite to chop out the original SourceGraphic. Because we used feMorphology to fatten the letters for our edges, we can now chop the original letter shapes out of the result of our feMerge.

<svg>
  <filter id="textFilter">

    <!-- more stuff -->

    <feMerge result="edges">
      <feMergeNode in="dark_edge" />
      <feMergeNode in="light_edge" />
    </feMerge>
    <feComposite in="edges" in2="SourceGraphic" operator="out" result="edges_complete" />

  </filter>
</svg>

See the Pen
SVG Glass Text Effect – edges combined by David Fitzgibbon (@loficodes)
on CodePen.

Now we’re starting to look like glass, with just one piece missing.

Step 9: Yes, a bevel

We have a pretty good 3D-looking glass effect. However, the letters look flat. Let’s add one more effect and make them look more rounded.

To achieve this we’re going to create a bevelled effect.

First we’re going to use feGaussianBlur. This will blur our existing filters slightly. We’re going to use this blurred result as basis to add some feSpecularLighting. As usual, feel free to play with the numbers here and see what effects you can get! The main one you might want to change is the lighting-color attribute. The image that we’re using here is slightly dark, so we’re using a bright lighting-color. If your image was very bright, this would make the letters hard to read, so you might use a darker lighting-color in that case.

<svg>
  <filter id="textFilter">
  
    <!-- more stuff -->

    <feGaussianBlur stdDeviation="5" result="bevel_blur" />
    <feSpecularLighting result="bevel_lighting" in="bevel_blur" specularConstant="2.4" specularExponent="13" lighting-color="rgba(60,60,60,.4)">
      <feDistantLight azimuth="25" elevation="40" />
    </feSpecularLighting>
    <feComposite in="bevel_lighting" in2="SourceGraphic" operator="in" result="bevel_complete" />

  </filter>
</svg>

See the Pen
SVG Glass Text Effect – bevel by David Fitzgibbon (@loficodes)
on CodePen.

Step 10: All together now!

Finally, with all the pieces ready, we do one last feMerge to get everything in place for the finished effect!

<svg>
  <filter id="textFilter">

    <!-- more stuff -->

    <feMerge result="complete">
      <feMergeNode in="edges_complete" />
      <feMergeNode in="bevel_complete" />
    </feMerge>
  </filter>
</svg>

Here’s everything together, nicely spaced out and commented:

<!-- VISIBLE SVG -->
<svg viewBox="0 0 1890 1260">
        
  <!-- BACKGROUND IMAGE - visible -->
  <image xlink:href="https://s3-us-west-2.amazonaws.com/s.cdpn.io/5946/kyoto.jpg" width="1890" x=0 height="1260" y=0 ></image>
    
  <!-- DISTORTION IMAGE - clipped -->
  <image xlink:href="https://s3-us-west-2.amazonaws.com/s.cdpn.io/5946/kyoto.jpg" width="1890" x=0 height="1260" y=0 clip-path="url(#clip)" filter= "url(#distortion)"></image>
    
  <!-- TEXT - clipped -->
  <clipPath id="clip">
    <text x="50%" y ="50%" dominant-baseline="middle" text-anchor="middle">KYOTO</text>
  </clipPath>
    
  <!-- TEXT - visible -->
  <text x="50%" y ="50%" dominant-baseline="middle" text-anchor="middle" filter="url(#textFilter)">KYOTO</text>
    
</svg>

<!-- FILTERS -->
<svg>
  <filter id="distortion">
    <feTurbulence type="turbulence" baseFrequency="0.05" numOctaves="2" result="turbulence"/>
    <feDisplacementMap in2="turbulence" in="SourceGraphic" scale="20" xChannelSelector="R" yChannelSelector="G"/>
  </filter>
    
  <filter id="textFilter">
            
    <!-- dark edge -->
    <feMorphology operator="dilate" radius="4" in="SourceAlpha" result="dark_edge_01" />
    <feOffset dx="5" dy="5" in="dark_edge_01" result="dark_edge_03"/>
    <feFlood flood-color="rgba(0,0,0,.5)" result="dark_edge_04" />
    <feComposite in="dark_edge_04" in2="dark_edge_03" operator="in" result="dark_edge" />     
            
    <!-- light edge -->
    <feMorphology operator="dilate" radius="4" in="SourceAlpha" result="light_edge_01" />
    <feOffset dx="-2" dy="-2" in="light_edge_01" result="light_edge_03"/>
    <feFlood flood-color="rgba(255,255,255,.5)" result="light_edge_04" />
    <feComposite in="light_edge_04" in2="light_edge_03" operator="in" result="light_edge" />
          
    <!-- edges together -->
    <feMerge result="edges">
      <feMergeNode in="dark_edge" />
      <feMergeNode in="light_edge" />
    </feMerge>
    <feComposite in="edges" in2="SourceGraphic" operator="out" result="edges_complete" />
          
    <!-- bevel -->
    <feGaussianBlur stdDeviation="5" result="bevel_blur" />
    <feSpecularLighting result="bevel_lighting" in="bevel_blur" specularConstant="2.4" specularExponent="13" lighting-color="rgba(60,60,60,.4)">
      <feDistantLight azimuth="25" elevation="40" />
    </feSpecularLighting>
    <feComposite in="bevel_lighting" in2="SourceGraphic" operator="in" result="bevel_complete" />

    <!-- everything in place -->
    <feMerge result="complete">
              <feMergeNode in="edges_complete" />
              <feMergeNode in="bevel_complete" />
    </feMerge>

  </filter>
</svg>

See the Pen
SVG Glass Text Effect by David Fitzgibbon (@loficodes)
on CodePen.

The post Making a Realistic Glass Effect with SVG appeared first on CSS-Tricks.

Post pobrano z: Branching Out from the Great Divide

I like the term Front-End Developer. It’s encapsulates the nature of your job if your concerns are:

• Building UIs for web browsers
• The spectrum of devices and platforms those web browsers run on
• The people who use those web browsers and related assistive technology

The breadth of knowledge for all-things front-end development has gotten super deep. I’ve found that front-end developers that have stretched themselves to the point they are thinking of themselves as full-stack developers more and more. I think that’s kinda cool and empowering, but it doesn’t mean that everyone needs to go that wide.

Brad Frost referred to sides of the spectrum as „back of the front” and „front of the front.” I once drew the line, in The Great Divide, as heavy JavaScript vs. not. These distinctions aren’t to divide people, but to acknowledge the spectrum and that there are people all over it.

In a new article called „Frontend Design, React, and a Bridge over the Great Divide,” Brad makes the point that the role of „Front-End Designer” exists on the spectrum right smack in the middle between design and development, where „development” refers to the back-end or deeper JavaScript stuff.

The jobs?

• Crafting semantic HTML markup
• Creating CSS code
• Authoring JavaScript that primarily manipulates objects in the DOM
• Testing across browsers and devices
• Optimizing the performance of front-end code
• Working with designers
• Working with back-end and application developers

That sounds like the „traditional” explanation of a front-end developer to me — if there is such a thing — but it makes sense to rename that role since front-end development is the term that got so wide.

Brad adds these responsibilties to the list:

• Create a library of presentational UI components
• Author and document a robust, intuitive component API for each presentational component
• Determine how flexible or rigid the component library should be
• Maintain the presentational components as a product

That’s where I think this metaphor comes in:

Me, Brad and a slew of you out there are front-end developers. We work in browsers and we care about the users and where and how they interact with those browsers. We do the things on Brad’s first list like craft HTML and CSS, work with designs and do testing. We share that common trunk of skills on the tree above.

But Brad is more of a systems designer than I am. His dot lands somewhere differently on that tree. I don’t know if I’m particularly skilled at anything, but my dot definitely falls elsewhere on that tree. Perhaps on an entirely different branch, as I quite like working with JavaScript tooling and logic and APIs and such. The bulk of Brad’s article is about React and finding a place in the realm of front-end development where the job isn’t ignoring React, but working with it in such a way that doesn’t mean every other aspect of development doesn’t have to come along for the ride.

The post Branching Out from the Great Divide appeared first on CSS-Tricks.

Post pobrano z: Branching Out from the Great Divide

I like the term Front-End Developer. It’s encapsulates the nature of your job if your concerns are:

• Building UIs for web browsers
• The spectrum of devices and platforms those web browsers run on
• The people who use those web browsers and related assistive technology

The breadth of knowledge for all-things front-end development has gotten super deep. I’ve found that front-end developers that have stretched themselves to the point they are thinking of themselves as full-stack developers more and more. I think that’s kinda cool and empowering, but it doesn’t mean that everyone needs to go that wide.

Brad Frost referred to sides of the spectrum as „back of the front” and „front of the front.” I once drew the line, in The Great Divide, as heavy JavaScript vs. not. These distinctions aren’t to divide people, but to acknowledge the spectrum and that there are people all over it.

In a new article called „Frontend Design, React, and a Bridge over the Great Divide,” Brad makes the point that the role of „Front-End Designer” exists on the spectrum right smack in the middle between design and development, where „development” refers to the back-end or deeper JavaScript stuff.

The jobs?

• Crafting semantic HTML markup
• Creating CSS code
• Authoring JavaScript that primarily manipulates objects in the DOM
• Testing across browsers and devices
• Optimizing the performance of front-end code
• Working with designers
• Working with back-end and application developers

That sounds like the „traditional” explanation of a front-end developer to me — if there is such a thing — but it makes sense to rename that role since front-end development is the term that got so wide.

Brad adds these responsibilties to the list:

• Create a library of presentational UI components
• Author and document a robust, intuitive component API for each presentational component
• Determine how flexible or rigid the component library should be
• Maintain the presentational components as a product

That’s where I think this metaphor comes in:

Me, Brad and a slew of you out there are front-end developers. We work in browsers and we care about the users and where and how they interact with those browsers. We do the things on Brad’s first list like craft HTML and CSS, work with designs and do testing. We share that common trunk of skills on the tree above.

But Brad is more of a systems designer than I am. His dot lands somewhere differently on that tree. I don’t know if I’m particularly skilled at anything, but my dot definitely falls elsewhere on that tree. Perhaps on an entirely different branch, as I quite like working with JavaScript tooling and logic and APIs and such. The bulk of Brad’s article is about React and finding a place in the realm of front-end development where the job isn’t ignoring React, but working with it in such a way that doesn’t mean every other aspect of development doesn’t have to come along for the ride.

The post Branching Out from the Great Divide appeared first on CSS-Tricks.

Post pobrano z: Using Netlify Forms and Netlify Functions to Build an Email Sign-Up Widget

Building and maintaining your own website is a great idea. Not only do you own your platform, but you get to experiment with web technologies along the way. Recently, I dug into a concept called serverless functions, starting with my own website. I’d like to share the results and what I learned along the way, so you can get your hands dirty, too!

But first, a 1-minute intro to serverless functions

A serverless function (sometimes called a lambda function or cloud function) is a piece of code that you can write, host, and run independently of your website, app, or any other code. Despite the name, serverless functions do, indeed, run on a server; but it’s a server you don’t have to build or maintain. Serverless functions are exciting because they take a lot of the legwork out of making powerful, scalable, apps.

There’s lots of great information on serverless functions out there, and a great place to start is CSS Trick’s own guide: The Power of Serverless Front-End Developers.

The Challenge: Build a Mailing List Sign Up Form

I started my journey with a challenge: I wanted to have an email list sign-up form on my site. The rules are as follows:

• It should work without JavaScript. I’d like to see how much I can get by with just CSS and HTML. Progressive enhancements are OK.
• It shouldn’t require external dependencies. This is a learning project, so I want to write 100% of the code if possible.
• It should use serverless functions. Instead of sending data to my email list service client-side, let’s do it server(less)-side!

Meet the team: 11ty, Netlify, and Buttondown

My website is built using a static site framework called 11ty. 11ty allows me to write templates and components in HTML, so that’s how we’ll build our email form. (Chris recently wrote a great article about his experience with 11ty if you’re interested in learning more.)

The website is then deployed using a service called Netlify) and it is the key player on our team here: the point guard, the quarterback, the captain. That’s because Netlify has three features that work together to produce serverless excellence:

• Netlify can deploy automatically from a GitHub repo. This means I can write my code, create a pull request, and instantly see if my code works. While there are tools to test serverless functions locally, Netlify makes it super easy to test live.
• Netlify Forms handles any form submissions my site gets. This is one part of the serverless equation: instead of writing code to collect submissions, I’ll configure the HTML with a few simple attributes and let Netlify handle the rest.
• Netlify Functions allows me to take action with the data from my forms. I’ll write some code to send emails off to my email list provider, and tell Netlify when to run that code.

Finally, I’ll manage my email list with a service called Buttondown. It’s a no-frills email newsletter provider, with an easy-to-use API.

Bonus: for personal sites like mine, 11ty, Netlify, and Buttondown are free. You can’t beat that.

The form

The HTML for my email subscription form is very minimal, with a few extras for Netlify Forms to work.

<form class="email-form" name="newsletter" method="POST" data-netlify="true" netlify-honeypot="bot-field">
  <div hidden aria-hidden="true">
    <label>
      Don’t fill this out if you're human: 
      <input name="bot-field" />
    </label>
  </div>
  <label for="email">Your email address</label>
  <div>
    <input type="email" name="email" placeholder="Email"  id="email" required />
    <button type="submit">Subscribe</button>
  </div>
</form>

First, I set the data-netlify attribute to true to tell Netlify to handle this form.

The first input in the form is named bot-field. This tricks robots into revealing themselves: I tell Netlify to watch for any suspicious submissions by setting the netlify-honeypot attribute to bot-field. I then hide the field from humans using the html hidden and aria-hidden values — users with and without assistive technology won’t be able to fill out the fake input.

If the form gets submitted with anything in the bot-field input, Netlify knows it’s coming from a robot, and ignores the input. In addition to this layer of protection, Netlify automatically filters suspicious submissions with Askimethttps://www.netlify.com/blog/2019/02/12/improved-netlify-forms-spam-filtering-using-akismet/). I don’t have to worry about spam!

The next input in the form is named email. This is where the email address goes! I’ve specified the input-type as email, and indicated that is required; this means that the browser will do all my validation for me, and won’t let users submit anything other than a valid email address.

Progressive enhancement with JavaScript

One neat feature of Netlify Forms is the ability to automatically redirect users to a “thank you” page when they submit a form. But ideally, I’d like to keep my users on the page. I wrote a short function to submit the form without a redirect.

const processForm = form => {
  const data = new FormData(form)
  data.append('form-name', 'newsletter');
  fetch('/', {
    method: 'POST',
    body: data,
  })
  .then(() => {
    form.innerHTML = `<div class="form--success">Almost there! Check your inbox for a confirmation e-mail.</div>`;
  })
  .catch(error => {
    form.innerHTML = `<div class="form--error">Error: ${error}</div>`;
  })
}

When I provide the content of my email form to this function via the form value, it submits the form using JavaScript’s built-in Fetch API. If the function was successful, it shows a pleasant message to the user. If the function hits a snag, it’ll tell my users that something went wrong.

This function is called whenever a user clicks the “submit” button on the form:

const emailForm = document.querySelector('.email-form')
if (emailForm) {
  emailForm.addEventListener('submit', e => {
    e.preventDefault();
    processForm(emailForm);
  })
}

This listener progressively enhances the default behavior of the form. This means that if the user has JavaScript disabled, the form still works!

The serverless function

Now that we have a working email submission form, it’s time to do some automation with a serverless function.

The way Netlify functions work is as follows:

1. Write the function in a JavaScript file in your project.
2. Tell Netlify where to look for your function via the netlify.toml file in your project.
3. Add any environment variables you’ll need via Netlify’s admin interface. An environment variable is something like an API key that you need to keep secret.

That’s it! The next time you deploy your site, the function will be ready to go.

The function for my site is going to be in the functions folder, so I have the following in my netlify.toml file:

[build]
  base = "."
  functions = "./functions"

Then, I’ll add a file in the functions folder called submission-created.js. It’s important to name the file submission-created so that Netlify knows to run it every time a new form submission occurs. A full list of events you can script against can be found in Netlify’s documentation. If you’ve correctly named and configured your function, you should see it on Netlify’s Functions dashboard:

The content in submission-created.js looks like this:

require('dotenv').config()
const fetch = require('node-fetch')
const { EMAIL_TOKEN } = process.env
exports.handler = async event => {
  const email = JSON.parse(event.body).payload.email
  console.log(`Recieved a submission: ${email}`)
  return fetch('https://api.buttondown.email/v1/subscribers', {
    method: 'POST',
    headers: {
      Authorization: `Token ${EMAIL_TOKEN}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ email }),
  })
    .then(response => response.json())
    .then(data => {
      console.log(`Submitted to Buttondown:\n ${data}`)
    })
    .catch(error => ({ statusCode: 422, body: String(error) }))
}

Let’s look at this line-by-line.

Line 1 includes a library called dotenv. This will help me use environment variables. Environment variables are useful to hold information that I don’t want to make public, like an API key. If I’m running my project locally, I set my environment variables with a .env file in the repo, and make sure it’s listed my .gitignore file. In order to deploy on Netlify, I also set up environment variables in Netlify’s web interface.

On line 2, I add a small library called node-fetch. This allows me to use Javascript’s Fetch API in node, which is how we’ll send data to Buttondown. Netlify automatically includes this dependency, as long as it’s listed in my project’s package.json file.

On line 3, I import my API key from the environment variables object, process.env.

Line 4 is where the function is defined. The exports.handler value is where Netlify expects to find our function, so we define it there. The only input we’ll need is the event value, which will contain all of the data from the form submission.

After retrieving the email address from the event value using JSON.parse, I’m ready to send it off to Buttondown. Here’s where I use the node-fetch library I imported earlier: I send a POST request to https://api.buttondown.email/v1/subscribers, including my API key in the header. Buttondown’s API doesn’t have many features, so it doesn’t take long to read through the documentation if you’d like to learn more.

The body of my POST request consists of the email address we retrieved.

Then (using the neat .then() syntax), I collect the response from Buttondown’s server. I do this so I can diagnose any issues that are happening with the process — Netlify makes it easy to check your function’s logs, so use console.log often!

Deploying the function

Now that I’ve written my function, configured my netlify.toml file, and added my environment variables, everything is ready to go. Deploying is painless: just set up Netlify’s GitHub integration, and your function will be deployed when your project is pushed.

Netlify projects can also be tested locally using Netlify Dev. Depending on the complexity of your code, it can be faster to develop locally: just run npm i netlify -g, then netlify dev. Netlify Dev will use the netlify.toml file to configure and run the project locally, including any serverless functions. Neat, right? One caveat: Netlify Dev currently can’t trigger serverless functions on form submissions, so you’ll have to test that using preview builds.

An idea for the future

Buttondown’s API has a few possible responses when I submit a new email. For instance, if a user submits an email that’s already subscribed to the list, I’d love to be able to tell them as soon as they submit the form.

Conclusion

All in all, I only had to write about 50 lines of code to have a functional email newsletter sign-up form available on my website. I wrote it all in HTML, CSS, and JavaScript, without having to fret with the server side of the equation. The form handles spam, and my readers get a nice experience whether they have JavaScript enabled or not.

The post Using Netlify Forms and Netlify Functions to Build an Email Sign-Up Widget appeared first on CSS-Tricks.