Post pobrano z: Everything You Ever Wanted to Know About inputmode

The inputmode global attribute provides a hint to browsers for devices with onscreen keyboards to help them decide which keyboard to display when a user has selected any input or textarea element.

<input type="text" inputmode="" />
<textarea inputmode="" />

Unlike changing the type of the form, inputmode doesn’t change the way the browser interprets the input — it instructs the browser which keyboard to display.

The inputmode attribute has a long history but has only very recently been adopted by the two major mobile browsers: Safari for iOS and Chrome for Android. Before that, it was implemented in Firefox for Android way back in 2012, and then subsequently removed several months later (though it is still available via a flag).

Almost six years later, Chrome for Android implemented the feature — and with the recent release of iOS 12.2, Safari now supports it too.

But before we go deep into the ins and outs of the attribute, consider that the WHATWG living standard provides inputmode documentation while the W3C 5.2 spec no longer lists it in its contents, which suggests they consider it obsolete. Given that WHATWG has documented it and browsers have worked toward supporting it, we’re going to go assume WHATWG specifications are the standard.

inputmode accepts a number of values. Let’s go through them, one by one.

None

<input type="text" inputmode="none" />

We’re starting here because it’s very possible we don’t want any type of keyboard on an input. Using inputmode=none will not show a keyboard at all on Chrome for Android. iOS 12.2 will still show its default alphanumeric keyboard, so specifying none could be sort of a reset for iOS in that regard. Regardless, none is intended for content that renders its own keyboard control.

Numeric

<input type="text" inputmode="numeric" />

This one is probably the one of the more common inputmode values out in the wild because it’s ideal for inputs that require numbers but no letters — things like PIN entry, zip codes, credit card numbers, etc. Using the numeric value with an input of type="text" may actually make more sense than setting the input to type="number" alone because, unlike a numeric input, inputmode="numeric" can be used with maxlength, minlength and pattern attributes, making it more versatile for different use cases.

I’ve often seen sites using type=tel on an input to display a numeric keyboard, and that checks out as a workaround, but isn’t semantically correct. If that bums you out, remember that inputmode supports patterns, we can add pattern="\d*" to the input for the same effect. That said, only use this if you are certain the input should only allow numeric input because Android (unlike iOS) doesn’t allow the user to change to the keyboard to use letters, which might inadvertently prevent users from submitting valid data.

Tel

<input type="text" inputmode="tel" />

Entering a telephone number using a standard alphanumeric keyboard can be a pain. For one, each number on a telephone keyboard (except 1 and 0) represents three letters (e.g. 2 represents A, B and C) which are displayed with the number. The alphanumeric keyboard does not reference those letters, so decoding a telephone number containing letters (e.g. 1-800-COLLECT) takes more mental power.

Using inputmode set to tel will produce a standard-looking telephone keyboard, including keys for digits 0 to 9, the pound (#) character, and the asterisk (*) character. Plus, we get those alphabetic mnemonic labels (e.g. ABC).

Decimal

<input type="text" inputmode="decimal" />

An inputmode set to the decimal value results in a subtle change in iOS where the keyboard appears to be exactly the same as the tel value, but replaces the +*# key with a simple decimal (.). On the flip side, this has no effect on Android, which will simply use the numeric keyboard.

Email

<input type="text" inputmode="email" />

I’m sure you (and at least someone you know) has filled out a form that asks for an email address, only to make you swap keyboards to access the @ character. It’s not life-threatening or anything, but certainly not a great user experience either.

That’s where the email value comes in. It brings the @ character into the fray, as well as the decimal (.) character.

This could also be a useful keyboard to show users who need to enter a Twitter username, given that@ is a core Twitter character for identifying users. However, the email address suggestions that iOS display above the keyboard may cause confusion.

Another use case could be if you have your own email validation script and don’t want to use the browsers built-in email validation.

URL

<input type="text" inputmode="url" />

The url value provides a handy shortcut for users to append TLDs (e.g. .com or .co.uk) with a single key, as well keys typically used in web addresses, like the dot (.) and forward slash (/) characters. The exact TLD displayed on the keyboard is tied to the user’s locale.

This could also be a useful keyboard to show users if your input accepts domain names (e.g. css-tricks.com) as well as full URIs (e.g. https://css-tricks.com). Use type="url" instead if your input requires validating the input.

Search

<input type="text" inputmode="search" />

This displays a blue Go key on iOS and a green Enter key on Android, both in place of where Return. As you may have guessed by the value’s name, search is useful for search forms, providing that submission key to make a query.

If you’d like to showSearch instead of Enter on iOS and a magnifying glass icon on Android in place of the green arrow, use type=search instead.

Other things you oughta know

• Chromium-based browsers on Android — such as Microsoft Edge, Brave and Opera — share the same inputmode behavior as Chrome.
• I haven’t included details of keyboards on iPad for the sake of brevity. It’s mostly the same as iPhone but includes more keys. Same is true for Android tablets, save for third-party keyboards, which might be another topic worth covering.
• The original proposed spec had the values kana and katakana for Japanese input but they were never implemented by any browser and have since been removed from the spec.
• latin-name was also one of the values of the original spec and has since been removed. Interestingly, if it’s used now on Safari for iOS, it will display the user’s name as a suggestion above the keyboard.

  

Demo

Oh, you want to see how all of these input modes work for yourself? Here’s a demo you can use on a device with a touchscreen keyboard to see the differences.

References

• WHATWG specification
• MDN documentation
• Caniuse
• Chrome Platform Status (Chromium Ticket #244688)

The post Everything You Ever Wanted to Know About inputmode appeared first on CSS-Tricks.

Post pobrano z: Everything You Ever Wanted to Know About inputmode

The inputmode global attribute provides a hint to browsers for devices with onscreen keyboards to help them decide which keyboard to display when a user has selected any input or textarea element.

<input type="text" inputmode="" />
<textarea inputmode="" />

Unlike changing the type of the form, inputmode doesn’t change the way the browser interprets the input — it instructs the browser which keyboard to display.

The inputmode attribute has a long history but has only very recently been adopted by the two major mobile browsers: Safari for iOS and Chrome for Android. Before that, it was implemented in Firefox for Android way back in 2012, and then subsequently removed several months later (though it is still available via a flag).

Almost six years later, Chrome for Android implemented the feature — and with the recent release of iOS 12.2, Safari now supports it too.

But before we go deep into the ins and outs of the attribute, consider that the WHATWG living standard provides inputmode documentation while the W3C 5.2 spec no longer lists it in its contents, which suggests they consider it obsolete. Given that WHATWG has documented it and browsers have worked toward supporting it, we’re going to go assume WHATWG specifications are the standard.

inputmode accepts a number of values. Let’s go through them, one by one.

None

<input type="text" inputmode="none" />

We’re starting here because it’s very possible we don’t want any type of keyboard on an input. Using inputmode=none will not show a keyboard at all on Chrome for Android. iOS 12.2 will still show its default alphanumeric keyboard, so specifying none could be sort of a reset for iOS in that regard. Regardless, none is intended for content that renders its own keyboard control.

Numeric

<input type="text" inputmode="numeric" />

This one is probably the one of the more common inputmode values out in the wild because it’s ideal for inputs that require numbers but no letters — things like PIN entry, zip codes, credit card numbers, etc. Using the numeric value with an input of type="text" may actually make more sense than setting the input to type="number" alone because, unlike a numeric input, inputmode="numeric" can be used with maxlength, minlength and pattern attributes, making it more versatile for different use cases.

I’ve often seen sites using type=tel on an input to display a numeric keyboard, and that checks out as a workaround, but isn’t semantically correct. If that bums you out, remember that inputmode supports patterns, we can add pattern="\d*" to the input for the same effect. That said, only use this if you are certain the input should only allow numeric input because Android (unlike iOS) doesn’t allow the user to change to the keyboard to use letters, which might inadvertently prevent users from submitting valid data.

Tel

<input type="text" inputmode="tel" />

Entering a telephone number using a standard alphanumeric keyboard can be a pain. For one, each number on a telephone keyboard (except 1 and 0) represents three letters (e.g. 2 represents A, B and C) which are displayed with the number. The alphanumeric keyboard does not reference those letters, so decoding a telephone number containing letters (e.g. 1-800-COLLECT) takes more mental power.

Using inputmode set to tel will produce a standard-looking telephone keyboard, including keys for digits 0 to 9, the pound (#) character, and the asterisk (*) character. Plus, we get those alphabetic mnemonic labels (e.g. ABC).

Decimal

<input type="text" inputmode="decimal" />

An inputmode set to the decimal value results in a subtle change in iOS where the keyboard appears to be exactly the same as the tel value, but replaces the +*# key with a simple decimal (.). On the flip side, this has no effect on Android, which will simply use the numeric keyboard.

Email

<input type="text" inputmode="email" />

I’m sure you (and at least someone you know) has filled out a form that asks for an email address, only to make you swap keyboards to access the @ character. It’s not life-threatening or anything, but certainly not a great user experience either.

That’s where the email value comes in. It brings the @ character into the fray, as well as the decimal (.) character.

This could also be a useful keyboard to show users who need to enter a Twitter username, given that@ is a core Twitter character for identifying users. However, the email address suggestions that iOS display above the keyboard may cause confusion.

Another use case could be if you have your own email validation script and don’t want to use the browsers built-in email validation.

URL

<input type="text" inputmode="url" />

The url value provides a handy shortcut for users to append TLDs (e.g. .com or .co.uk) with a single key, as well keys typically used in web addresses, like the dot (.) and forward slash (/) characters. The exact TLD displayed on the keyboard is tied to the user’s locale.

This could also be a useful keyboard to show users if your input accepts domain names (e.g. css-tricks.com) as well as full URIs (e.g. https://css-tricks.com). Use type="url" instead if your input requires validating the input.

Search

<input type="text" inputmode="search" />

This displays a blue Go key on iOS and a green Enter key on Android, both in place of where Return. As you may have guessed by the value’s name, search is useful for search forms, providing that submission key to make a query.

If you’d like to showSearch instead of Enter on iOS and a magnifying glass icon on Android in place of the green arrow, use type=search instead.

Other things you oughta know

• Chromium-based browsers on Android — such as Microsoft Edge, Brave and Opera — share the same inputmode behavior as Chrome.
• I haven’t included details of keyboards on iPad for the sake of brevity. It’s mostly the same as iPhone but includes more keys. Same is true for Android tablets, save for third-party keyboards, which might be another topic worth covering.
• The original proposed spec had the values kana and katakana for Japanese input but they were never implemented by any browser and have since been removed from the spec.
• latin-name was also one of the values of the original spec and has since been removed. Interestingly, if it’s used now on Safari for iOS, it will display the user’s name as a suggestion above the keyboard.

  

Demo

Oh, you want to see how all of these input modes work for yourself? Here’s a demo you can use on a device with a touchscreen keyboard to see the differences.

References

• WHATWG specification
• MDN documentation
• Caniuse
• Chrome Platform Status (Chromium Ticket #244688)

The post Everything You Ever Wanted to Know About inputmode appeared first on CSS-Tricks.

Post pobrano z: Weekly news: PWA Issue on iOS, Performance Culture, Anti-Tracking in Browsers

Šime posts regular content for web developers on webplatform.news. Each week, he covers timely news at the intersection of development standards and the tools that make them available on the web.

Installed PWAs cannot easily be restarted on iOS

iOS 12.2 PWAs
🔁 In-App browser for external content (OAuth)
💾 New lifecycle (No Reload)
🔙Navigation gestures
🤝WebShare
⚠️Motion Sensors disabled; old getUserMedia removed
👍 IntersectionObserver, ConicGradients, datalist, color picker, AbortFetchhttps://t.co/LNzq6MzqjR

— Maximiliano Firtman @ 🇱🇹 Vilnius (@firt) March 26, 2019

Maximiliano Firtman: On iOS, it is not possible to restart an installed PWA by closing it from the recently used apps screen and then immediately reopening it. Instead of restarting the app, iOS restores its state. This can be a problem for users if the PWA gets stuck in a broken state.

<input> with type 'file' bug on #iOS 12.2 #PWA
Open the input, put the PWA in bg by pressing home button. The input stops working. True for any input with type 'file' throughout the app. It works after a phone restart. pic.twitter.com/IfzsXy91RK

— Pankaj Nathani ⭐️ (@croozeus) April 11, 2019

After some undefined time, the saved context seems to disappear. So if you get out of the PWA, do nothing with your phone and wait some hours to go back to the PWA, it restarts from scratch.

Instilling a performance culture at The Telegraph

We've been working hard at The Telegraph to improve third-party performance. Here is an insight into our approach – https://t.co/4hhRDYaidS #webperf ⚡️

— Gareth Clubb (@digitalclubb) April 30, 2019

Gareth Clubb: At The Telegraph (a major UK newspaper), we set up a web performance working group to tackle our “organizational” performance challenges and instill a performance culture. The group meets regularly to review third-party tags and work on improving our site’s performance.

We’ve started deferring all JavaScript (including our own) using the <script defer> attribute. This change alone nearly doubled our (un-throttled) Lighthouse performance score.

Deferring our JavaScript hasn’t skewed any existing analytics and it certainly hasn’t delayed any advertising. […] The First Ad Loaded metric improved by an average of four seconds.

We also removed 1 MB of third-party payload from our new front end. When one of our teams requests the addition of any new script, we now test the script in isolation and reject it if it degrades our metrics (first contentful paint, etc.).

When we started this process, we had a collection of very old scripts and couldn’t track the original requester. We removed those on the premise that, if they were important, people would get back in touch — no one did.

Microsoft plans to add tracking prevention to the Edge browser

Kyle Pflug: Microsoft has announced plans to add options for blocking trackers to the Edge browser. Malicious trackers would be blocked automatically, and the user would have the option to additionally block all potential trackers.

This would make Edge the fourth major browser with some form of built-in anti-tracking feature (two other major browsers, Opera and UC Browser, include ad blockers instead).

1. In 2015, Firefox added Tracking Protection — recently renamed to Content Blocking — becoming the first major browser to protect users from third-party trackers (when browsing the web in private mode).
2. Since 2017, Safari prevents cross-site tracking by default, through a feature called Intelligent Tracking Prevention (ITP). Users are prompted to allow tracking when they try to interact with third-party widgets on websites.

   

3. Earlier this year, Samsung Internet added an experimental feature called Smart Anti-Tracking that denies third-party trackers access to cookies.

The post Weekly news: PWA Issue on iOS, Performance Culture, Anti-Tracking in Browsers appeared first on CSS-Tricks.

Post pobrano z: Decaying Sites

Websites have a tendency to decay all by themselves. Link rot, they call it. Unpaid domain name registrations. Companies that have gone out of business. Site owners that have lost interest. What’s sadder than a 404? Landing on a holding page of a URL that used to exist, but now has fallen into the hands of some domain hoarder after it expired, hoping someone will pay a premium to get it back.

That stuff is no fun. But what about sites that are totally still around, just old? What kind of fun things could we do to indicate oldness that’s, like, on purpose?

On the CodePen blog, we call out blog posts that haven’t been updated in at least a couple of years. We update documentation, sure, but we tend to leave blog posts alone as a historical record. So, we’re pretty clear about that:

<?php if (get_the_modified_date("Y") < 2017) { ?>
  <p class="callout"><strong>Heads up!</strong> This blog post hasn't been updated in over 2 years. CodePen is an ever changing place, so if this post references features, you're probably better off checking the <a href="/documentation/">docs</a>. Get in touch with <a href="https://codepen.io/support/">support</a> if you have further questions.</p>
<?php } ?>

We style it up like a little warning:

But what if it was less obvious? What if the text just kinda started going all to crap? Words falling off their lines and going out of focus? The older the content, the more decay:

See the Pen
Decayed Text by Chris Coyier (@chriscoyier)
on CodePen.

What if you let a site decaye on purpose? Say, perhaps, you’re holding oto client work and the client hasn’t paid their bill. Dragoi Ciprian has a little idea (repo) for that. You set the due date and deadline:

var due_date = new Date('2017-02-27');
var days_deadline = 60;

Here’s a demo of that. As I write, I’m 30 days into a 90-day deadline. If the demo looks blank to you, well, I guess I should have paid my bill so this code could have been removed 😉

See the Pen
not-paid Demo by Chris Coyier (@chriscoyier)
on CodePen.

Or maybe the screen could kinda flash red, like you’re getting hit in a video game.

Or you could get all glitchy! (This demo is click-to-load, fast colors and motion warning.)

See the Pen
Glitchy loader by Nathaniel Inman (@NathanielInman)
on CodePen.

See the Pen
CSS Glitched Text by Lucas Bebber (@lbebber)
on CodePen.

Perhaps rather than basing things off a payment due date or the age of the content, these effects come into play based on how long it’s been since the site’s dependencies have been updated. Or at least had some kind of deployment push.

---

This is only sorta tangentially related, but it reminds me of the very, very scary game Lose/Lose:

Lose/Lose is a video-game with real life consequences. Each alien in the game is created based on a random file on the players [sic] computer. If the player kills the alien, the file it is based on is deleted. If the players [sic] ship is destroyed, the application itself is deleted.

Although touching aliens will cause the player to lose the game, and killing aliens awards points, the aliens will never actually fire at the player. This calls into question the player’s mission, which is never explicitly stated, only hinted at through classic game mechanics. Is the player supposed to be an aggressor? Or merely an observer, traversing through a dangerous land?

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Post pobrano z: A Couple of New Wufoo Tips

(This is a sponsored post.)

High fives to Wufoo, our long-time sponsor here on CSS-Tricks. It’s powered the vast majority of forms I’ve built over the past decade. If you’ve never used it or heard of it: it’s a form builder. It makes the arduous task of implementing forms trivially easy. Building a form on Wufoo means you’ll get a form that does everything right UX-wise, gives you full design control, integrates with anything, and that you can put anywhere.

The feature list is too long to cover in the confines of a single post, so I always like to cover little bits that I’ve used recently and liked.

1. They just released a much quicker way to rename a form both in the Form Manager and inside the form itself.
2. Don’t forget they have a robust API. I used the API to submit form entries on a form just the other day. I wanted to do some special things on a form, like be able to react to the DOM event of submitting the form. That’s not really possible when the form is in an <iframe>, but just fine when you host the form yourself and submit via API. Worked great.

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Post pobrano z: Undefined: The Third Boolean Value

I wanted to implement a notification message in one of my projects, similar to what you’d see in Google Docs while a document is saving. In other words, a message shows up indicating that the document is saving every time a change is made. Then, once the changes are saved, the message becomes: “All changes saved in Drive.”

Let’s take a look at how we might do that using a boolean value, but actually covering three possible states. This definitely isn’t the only way to do this, and frankly, I’m not even sure if it’s the best way. Either way, it worked for me.

Here’s an example of that “Saving…” state:

…and the “Saved” state:

Using a Boolean value for to define the state was my immediate reaction. I could have a variable called isSaving and use it to render a conditional string in my template, like so:

let isSaving;

…and in the template:

<span>{{ isSaving ? ‘Saving...’ : ‘All changes saved’ }}</span>

Now, whenever we start saving, we set the value to true and then set it to false whenever no save is in progress. Simple, right?

There is a problem here, though, and it’s a bit of a UX issue. The default message is rendered as “All changes saved.” When the user initially lands on the page, there is no saving taking place and we get the “Saved” message even though no save ever happened. I would prefer showing nothing until the first change triggers the first “Saving” message.

This calls for a third state in our variable: isSaving. Now the question becomes: do we change the value to a string variable as one of the three states? We could do that, but what if we could get the third state in our current boolean variable itself?

isSaving can take two values: true or false. But what is the value directly after we have declared it in the statement: let isSaving;? It’s undefined because the value of any variable is undefined when it’s declared, unless something is assigned to it. Great! We can use that initial undefined value to our advantage… but, this will require a slight change in how we write our condition in the template.

The ternary operator we are using evaluates to the second expression for anything that can’t be converted to true. The values undefined and false both are not true and, hence, resolve as false for the ternary operator. Even an if/else statement would work a similar way because else is evaluated for anything that isn’t true. But we want to differentiate between undefined and false . This is fixable by explicitly checking for false value, too, like so:

<span>
{{ isSaving === true ? 
  ‘Saving...’ : 
  (isSaving === false ? ‘All changes saved’: ‘’) 
}}
</span>

We are now strictly checking for true and false values. This made our ternary operator a little nested and difficult to read. If our template supports if/else statements, then we can refactor the template like this:

<span>
{% if isSaving === true %}
  Saving...
{% elseif isSaving === false %}
  All changes saved
{% endif %}
</span>

Aha! Nothing renders when the variable is neither true nor false — exactly what we want!

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Post pobrano z: Revisiting the Rendering Tier

Have you ever created a well-intentioned, thoughtful design system only to watch it grow into an ever-increasing and scary codebase? I’ve been working in sort of the opposite direction, inheriting the scary codebase and trying to create a thoughtful system from it.

Here’s Alex Sanders on the topic, explaining how his team at The Guardian has tackled the task of creating design systems while combating complexity:

Systems that try to contain complexity over long periods of time by convention will inevitably tend toward entropy, because one significant characteristic of convention is that it is trivially simple to break one.

You do not even need to be malicious. A convention is not a line in the sand. You can have a very good case for breaking or stretching one, but once a convention is no longer fully observed, subsequent cases for breaking or stretching it are automatically stronger, because the convention is already weakened. The more this happens, the weaker it gets.

Complexity and entropy can be two outcomes in the same situation, but need not be mutually exclusive. Interesting to think that our best intentions to guard against complexity can be somewhat destructive.

I also love how Alex explains why it’s not possible for their team to use a Tachyons-esque approach to writing styles because of the way that their development environment is kinda slow. It would be painful for the team to make that switch, despite how it could solve some other problems. This reminded me that measuring problems in this way is why there can never be a single way to write CSS. We need that inherent flexibility, even at the expense of introducing inconsistencies. Hence, conventions being less of a line in the sand and more of a guide post.

On a separate note, I really like how Alex describes styles and attributes as the reasons why his team is writing those styles. It’s about aligning with business objectives:

…tens of thousands of rules that are intended to describe a maintainable set of responses to business and design problems.

That’s interesting since I don’t think we spend much time here talking specifically about the business side of CSS and the functional requirements that a styled user interface needs to accomplish.

And perhaps thinking about that can help us write better styles in the long term. Is this line of CSS solving a problem? Does this new class resolve an issue that will help our customers? These are good questions to keep in mind as we work, yet I know I don’t spend enough time thinking about them. I often see the design I’m turning into code as a problem to be solved instead.

Perhaps we should expand the way we styling a webpage because maybe, just maybe, it will help us write more maintainable code that’s built to solve a real business objective.

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Post pobrano z: Scroll-Linked Animations

You scroll down to a certain point, now you want to style things in a certain way. A header becomes fixed. An animation triggers. A table of contents appears. To do anything based on scroll position, JavaScript is required right now. You watch the scroll position via a DOM event and alter an element’s styling based on that position. Or, probably better if you can, use IntersectionObserver. We just blogged about all this.

Now there is a new (unofficial) spec trying to bring these possibilities to CSS. I love it when web standards get involved because it sees authors like us trying to pull off certain design effects and wants to (presumably) help make it easier and more performant. I also like how this spec lists editors from Mozilla and Google and Apple.

I wonder how they’ll handle the infinite-loop stuff here. Like you scroll to a point, it triggers some animation, which moves some element such that it changes the scroll position, which stops the animation, which moves the scroll position again… etc. I also wonder why it’s all specific to animation. „Scroll-position styling” seems like it would have the widest appeal and use level of usefulness.

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Post pobrano z: Creating a Reusable Pagination Component in Vue

The idea behind most of web applications is to fetch data from the database and present it to the user in the best possible way. When we deal with data there are cases when the best possible way of presentation means creating a list.

Depending on the amount of data and its content, we may decide to show all content at once (very rarely), or show only a specific part of a bigger data set (more likely). The main reason behind showing only part of the existing data is that we want to keep our applications as performant as possible and avoid loading or showing unnecessary data.

If we decide to show our data in „chunks” then we need a way to navigate through that collection. The two most common ways of navigating through set of data are:

The first is pagination, a technique that splits the set of data into a specific number of pages, saving users from being overwhelmed by the amount of data on one page and allowing them to view one set of results at a time. Take this very blog you’re reading, for example. The homepage lists the latest 10 posts. Viewing the next set of latest posts requires clicking a button.

The second common technique is infinite scrolling, something you’re likely familiar with if you’ve ever scrolled through a timeline on either Facebook or Twitter.

We’re going to take a deeper look at the first type in this post. Pagination is something we encounter on a near-daily basis, yet making it is not exactly trivial. It’s a great use case for a component, so that’s exactly what we’re going to do. We will go through the process of creating a component that is in charge of displaying that list, and triggering the action that fetches additional articles when we click on a specific page to be displayed. In other words, we’re making a pagination component in Vue.js like this:

Let’s go through the steps together.

Step 1: Create the ArticlesList component in Vue

Let’s start by creating a component that will show a list of articles (but without pagination just yet). We’ll call it ArticlesList. In the component template, we’ll iterate through the set of articles and pass a single article item to each ArticleItem component.

// ArticlesList.vue
<template>
  <div>
    <ArticleItem
      v-for="article in articles"
      :key="article.publishedAt"
      :article="article"
    />
  </div>
</template>

In the script section of the component, we set initial data:

• articles: This is an empty array filled with data fetched from the API on mounted hook.
• currentPage: This is used to manipulate the pagination.
• pageCount : This is the total number of pages, calculated on mounted hook based on the API response.
• visibleItemsPerPageCount: This is how many articles we want to see on a single page.

At this stage, we fetch only first page of the article list. This will give us a list two articles:

// ArticlesList.vue
import ArticleItem from "./ArticleItem"
import axios from "axios"
export default {
  name: "ArticlesList",
  static: {
    visibleItemsPerPageCount: 2
  },
  data() {
    return {
      articles: [],
      currentPage: 1,
      pageCount: 0
    }
  },
  components: { 
    ArticleItem, 
  },
  async mounted() {
    try {
      const { data } = await axios.get(
        `?country=us&page=1&pageSize=${
          this.$options.static.visibleItemsPerPageCount
        }&category=business&apiKey=065703927c66462286554ada16a686a1`
      )
      this.articles = data.articles
      this.pageCount = Math.ceil(
        data.totalResults / this.$options.static.visibleItemsPerPageCount
      )
    } catch (error) {
      throw error
    }
  }
}

Step 2: Create pageChangeHandle method

Now we need to create a method that will load the next page, the previous page or a selected page.

In the pageChangeHandle method, before loading new articles, we change the currentPage value depending on a property passed to the method and fetch the data respective to a specific page from the API. Upon receiving new data, we replace the existing articles array with the fresh data containing a new page of articles.

// ArticlesList.vue
...
export default {
...
  methods: {
    async pageChangeHandle(value) {
      switch (value) {
        case 'next':
          this.currentPage += 1
          break
        case 'previous':
          this.currentPage -= 1
          break
        default:
          this.currentPage = value
      }
      const { data } = await axios.get(
        `?country=us&page=${this.currentPage}&pageSize=${
          this.$options.static.visibleItemsPerPageCount
        }&category=business&apiKey=065703927c66462286554ada16a686a1`
      )
      this.articles = data.articles
    }
  }
}

Step 3: Create a component to fire page changes

We have the pageChangeHandle method, but we do not fire it anywhere. We need to create a component that will be responsible for that.

This component should do the following things:

1. Allow the user to go to the next/previous page.
2. Allow the user to go to a specific page within a range from currently selected page.
3. Change the range of page numbers based on the current page.

If we were to sketch that out, it would look something like this:

Let’s proceed!

Requirement 1: Allow the user to go to the next or previous page

Our BasePagination will contain two buttons responsible for going to the next and previous page.

// BasePagination.vue
<template>
  <div class="base-pagination">
    <BaseButton
      :disabled="isPreviousButtonDisabled"
      @click.native="previousPage"
    >
      ←
    </BaseButton>
    <BaseButton
      :disabled="isNextButtonDisabled"
      @click.native="nextPage"
    >
      →
    </BaseButton>
  </div>
</template>

The component will accept currentPage and pageCount properties from the parent component and emit proper actions back to the parent when the next or previous button is clicked. It will also be responsible for disabling buttons when we are on the first or last page to prevent moving out of the existing collection.

// BasePagination.vue
import BaseButton from "./BaseButton.vue";
export default {
  components: {
    BaseButton
  },
  props: {
    currentPage: {
      type: Number,
      required: true
    },
    pageCount: {
      type: Number,
      required: true
    }
  },
  computed: {
    isPreviousButtonDisabled() {
      return this.currentPage === 1
    },
    isNextButtonDisabled() {
      return this.currentPage === this.pageCount
    }
  },
  methods: {
    nextPage() {
      this.$emit('nextPage')
    },
    previousPage() {
      this.$emit('previousPage')
    }
  }

We will render that component just below our ArticleItems in ArticlesList component.

// ArticlesList.vue
<template>
  <div>
    <ArticleItem
      v-for="article in articles"
      :key="article.publishedAt"
      :article="article"
    />
    <BasePagination
      :current-page="currentPage"
      :page-count="pageCount"
      class="articles-list__pagination"
      @nextPage="pageChangeHandle('next')"
      @previousPage="pageChangeHandle('previous')"
    />
  </div>
</template>

That was the easy part. Now we need to create a list of page numbers, each allowing us to select a specific page. The number of pages should be customizable and we also need to make sure not to show any pages that may lead us beyond the collection range.

Requirement 2: Allow the user to go to a specific page within a range

Let’s start by creating a component that will be used as a single page number. I called it BasePaginationTrigger. It will do two things: show the page number passed from the BasePagination component and emit an event when the user clicks on a specific number.

// BasePaginationTrigger.vue
<template>
  <span class="base-pagination-trigger" @click="onClick">
    {{ pageNumber }}
  </span>
</template>
<script>
export default {
  props: {
    pageNumber: {
      type: Number,
      required: true
    }
  },
  methods: {
    onClick() {
      this.$emit("loadPage", this.pageNumber)
    }
  }
}
</script>

This component will then be rendered in the BasePagination component between the next and previous buttons.

// BasePagination.vue
<template>
  <div class="base-pagination">
    <BaseButton />
    ...
    <BasePaginationTrigger
      class="base-pagination__description"
      :pageNumber="currentPage"
      @loadPage="onLoadPage"
    />
    ...
    <BaseButton />
  </div>
</template>

In the script section, we need to add one more method (onLoadPage) that will be fired when the loadPage event is emitted from the trigger component. This method will receive a page number that was clicked and emit the event up to the ArticlesList component.

// BasePagination.vue
export default {
  ...
    methods: {
    ...
    onLoadPage(value) {
      this.$emit("loadPage", value)
    }
  }
}

Then, in the ArticlesList, we will listen for that event and trigger the pageChangeHandle method that will fetch the data for our new page.

// ArticlesList
<template>
  ...
    <BasePagination
      :current-page="currentPage"
      :page-count="pageCount"
      class="articles-list__pagination"
      @nextPage="pageChangeHandle('next')"
      @previousPage="pageChangeHandle('previous')"
      @loadPage="pageChangeHandle"
    />
  ...
</template>

Requirement 3: Change the range of page numbers based on the current page

OK, now we have a single trigger that shows us the current page and allows us to fetch the same page again. Pretty useless, don’t you think? Let’s make some use of that newly created trigger component. We need a list of pages that will allow us to jump from one page to another without needing to go through the pages in between.

We also need to make sure to display the pages in a nice manner. We always want to display the first page (on the far left) and the last page (on the far right) on the pagination list and then the remaining pages between them.

We have three possible scenarios:

1. The selected page number is smaller than half of the list width (e.g. 1 – 2 – 3 – 4 – 18)
2. The selected page number is bigger than half of the list width counting from the end of the list (e.g. 1 – 15 – 16 – 17 – 18)
3. All other cases (e.g. 1 – 4 – 5 – 6 – 18)

To handle these cases, we will create a computed property that will return an array of numbers that should be shown between the next and previous buttons. To make the component more reusable we will accept a property visiblePagesCount that will specify how many pages should be visible in the pagination component.

Before going to the cases one by one we create few variables:

• visiblePagesThreshold:- Tells us how many pages from the centre (selected page should be shown)
• paginationTriggersArray: Array that will be filled with page numbers
• visiblePagesCount: Creates an array with the required length

// BasePagination.vue
export default {
  props: {
    visiblePagesCount: {
      type: Number,
      default: 5
    }
  }
  ...
  computed: {
    ...
      paginationTriggers() {
        const currentPage = this.currentPage
        const pageCount = this.pageCount
        const visiblePagesCount = this.visiblePagesCount
        const visiblePagesThreshold = (visiblePagesCount - 1) / 2
        const pagintationTriggersArray = Array(this.visiblePagesCount - 1).fill(0)
      }
    ...
    }
  ...
}

Now let’s go through each scenario.

Scenario 1: The selected page number is smaller than half of the list width

We set the first element to always be equal to 1. Then we iterate through the list, adding an index to each element. At the end, we add the last value and set it to be equal to the last page number — we want to be able to go straight to the last page if we need to.

if (currentPage <= visiblePagesThreshold + 1) {
  pagintationTriggersArray[0] = 1
  const pagintationTriggers = pagintationTriggersArray.map(
    (paginationTrigger, index) => {
      return pagintationTriggersArray[0] + index
    }
  )
  pagintationTriggers.push(pageCount)
  return pagintationTriggers
}

Scenario 2: The selected page number is bigger than half of the list width counting from the end of the list

Similar to the previous scenario, we start with the last page and iterate through the list, this time subtracting the index from each element. Then we reverse the array to get the proper order and push 1 into the first place in our array.

if (currentPage >= pageCount - visiblePagesThreshold + 1) {
  const pagintationTriggers = pagintationTriggersArray.map(
    (paginationTrigger, index) => {
      return pageCount - index
    }
  )
  pagintationTriggers.reverse().unshift(1)
  return pagintationTriggers
}

Scenario 3: All other cases

We know what number should be in the center of our list: the current page. We also know how long the list should be. This allows us to get the first number in our array. Then we populate the list by adding an index to each element. At the end, we push 1 into the first place in our array and replace the last number with our last page number.

pagintationTriggersArray[0] = currentPage - visiblePagesThreshold + 1
const pagintationTriggers = pagintationTriggersArray.map(
  (paginationTrigger, index) => {
    return pagintationTriggersArray[0] + index
  }
)
pagintationTriggers.unshift(1);
pagintationTriggers[pagintationTriggers.length - 1] = pageCount
return pagintationTriggers

That covers all of our scenarios! We only have one more step to go.

Step 5: Render the list of numbers in BasePagination component

Now that we know exactly what number we want to show in our pagination, we need to render a trigger component for each one of them.

We do that using a v-for directive. Let’s also add a conditional class that will handle selecting our current page.

// BasePagination.vue
<template>
  ...
  <BasePaginationTrigger
    v-for="paginationTrigger in paginationTriggers"
    :class="{
      'base-pagination__description--current':
        paginationTrigger === currentPage
    }"
    :key="paginationTrigger"
    :pageNumber="paginationTrigger"
    class="base-pagination__description"
    @loadPage="onLoadPage"
  />
  ...
</template>

And we are done! We just built a nice and reusable pagination component in Vue.

When to avoid this pattern

Although this component is pretty sweet, it’s not a silver bullet for all use cases involving pagination.

For example, it’s probably a good idea to avoid this pattern for content that streams constantly and has a relatively flat structure, like each item is at the same level of hierarchy and has a similar chance of being interesting to the user. In other words, something less like an article with multiple pages and something more like main navigation.

Another example would be browsing news rather than looking for a specific news article. We do not need to know where exactly the news is and how much we scrolled to get to a specific article.

That’s a wrap!

Hopefully this is a pattern you will be able to find useful in a project, whether it’s for a simple blog, a complex e-commerce site, or something in between. Pagination can be a pain, but having a modular pattern that not only can be re-used, but considers a slew of scenarios, can make it much easier to handle.

The post Creating a Reusable Pagination Component in Vue appeared first on CSS-Tricks.

Post pobrano z: You probably don’t need input type=“number”

Brad Frost wrote about a recent experience with a website that used <input type="number">:

Last week I got a call from my bank regarding a wire transfer I had just scheduled. The customer support guy had me repeat everything back to him because there seemed to be a problem with the information. “Hmmmm, everything you said is right right except the last 3 digits of the account number.”

He had me resubmit the wire transfer form. When I exited the account number field, the corner of my eye noticed the account number change ever so slightly. I quickly refocused into the field and slightly moved my index finger up on my Magic Mouse. It started looking more like a slot machine than an input field!

Brad argues that we then shouldn’t be using <input type="number"> for “account numbers, social security numbers, credit card numbers, confirmation numbers” which makes a bunch of sense to me! Instead we can use the pattern attribute that Chris Ferdinandi looked at a while back in a post all about constraint validation in HTML.

It’s worth mentioning that numeric inputs can be more complex than they appear and that their appearance and behavior vary between browsers. All good things to consider along alongside Brad’s advice when evaluating user experience.

Also:

<input inputmode="numeric"> is the way forward for mobile numeric keyboards (paired with `pattern="[0-9]*"` on iOS pending inputmode support).

Note: positive integers only!https://t.co/R9WuwXy106 https://t.co/2HiSq4ZXK0

— Zach Leatherman (@zachleat) March 25, 2019

Direct Link to Article — Permalink

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