A Flutter Package for Showing a Country Code Selector

country_code_picker .A flutter package for showing a country code selector.

It supports i18n.

Usage

Just put the component in your application setting the onChanged callback.

@override
 Widget build(BuildContext context) => new Scaffold(
     body: Center(
       child: CountryCodePicker(
         onChanged: print,
         // Initial selection and favorite can be one of code ('IT') OR dial_code('+39')
         initialSelection: 'IT',
         favorite: ['+39','FR'],
         // optional. Shows only country name and flag
         showCountryOnly: false,
         // optional. Shows only country name and flag when popup is closed.
         showOnlyCountryWhenClosed: false,
         // optional. aligns the flag and the Text left
         alignLeft: false,
       ),
     ),
 );

Example:

void _onCountryChange(CountryCode countryCode) {
    //TODO : manipulate the selected country code here
    print("New Country selected: " + countryCode.toString());
  }

i18n

Just add the CountryLocalizations.delegate in the list of your app delegates

 return new MaterialApp(
      supportedLocales: [
        Locale('en'),
        Locale('it'),
        Locale('fr'),
        Locale('es'),
      ],
      localizationsDelegates: [
        CountryLocalizations.delegate,
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
      ],

Customization

Here is a list of properties available to customize your widget:

Name Type Description
onChanged ValueChanged callback invoked when the selection changes
onInit ValueChanged callback invoked during initialization of the widget
initialSelection String used to set the initial selected value
favorite List used to populate the favorite country list
textStyle TextStyle TextStyle applied to the widget button
padding EdgeInsetsGeometry the padding applied to the button
showCountryOnly bool true if you want to see only the countries in the selection dialog
searchDecoration InputDecoration decoration applied to the TextField search widget
searchStyle TextStyle style applied to the TextField search widget text
emptySearchBuilder WidgetBuilder use this to customize the widget used when the search returns 0 elements
builder Function(CountryCode) use this to build a custom widget instead of the default FlatButton
enabled bool set to false to disable the widget
textOverflow TextOverflow the button text overflow behaviour
dialogSize Size the size of the selection dialog
countryFilter List uses a list of strings to filter a sublist of countries
showOnlyCountryWhenClosed bool if true it’ll show only the country
alignLeft bool aligns the flag and the Text to the left
showFlag bool shows the flag everywhere
showFlagMain bool shows the flag only when closed
showFlagDialog bool shows the flag only in dialog
flagWidth double the width of the flags
comparator Comparator use this to sort the countries in the selection dialog
hideSearch bool if true the search feature will be disabled

Contributions

Contributions of any kind are more than welcome! Feel free to fork and improve country_code_picker in any way you want, make a pull request, or open an issue.

Download Details:

Author: imtoori

GitHub: https://github.com/imtoori/CountryCodePicker

#flutter #dart

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A Flutter Package for Showing a Country Code Selector
Callum Slater

Callum Slater

1653465344

PySpark Cheat Sheet: Spark DataFrames in Python

This PySpark SQL cheat sheet is your handy companion to Apache Spark DataFrames in Python and includes code samples.

You'll probably already know about Apache Spark, the fast, general and open-source engine for big data processing; It has built-in modules for streaming, SQL, machine learning and graph processing. Spark allows you to speed analytic applications up to 100 times faster compared to other technologies on the market today. Interfacing Spark with Python is easy with PySpark: this Spark Python API exposes the Spark programming model to Python. 

Now, it's time to tackle the Spark SQL module, which is meant for structured data processing, and the DataFrame API, which is not only available in Python, but also in Scala, Java, and R.

Without further ado, here's the cheat sheet:

PySpark SQL cheat sheet

This PySpark SQL cheat sheet covers the basics of working with the Apache Spark DataFrames in Python: from initializing the SparkSession to creating DataFrames, inspecting the data, handling duplicate values, querying, adding, updating or removing columns, grouping, filtering or sorting data. You'll also see that this cheat sheet also on how to run SQL Queries programmatically, how to save your data to parquet and JSON files, and how to stop your SparkSession.

Spark SGlL is Apache Spark's module for working with structured data.

Initializing SparkSession 
 

A SparkSession can be used create DataFrame, register DataFrame as tables, execute SGL over tables, cache tables, and read parquet files.

>>> from pyspark.sql import SparkSession
>>> spark a SparkSession \
     .builder\
     .appName("Python Spark SQL basic example") \
     .config("spark.some.config.option", "some-value") \
     .getOrCreate()

Creating DataFrames
 

Fromm RDDs

>>> from pyspark.sql.types import*

Infer Schema

>>> sc = spark.sparkContext
>>> lines = sc.textFile(''people.txt'')
>>> parts = lines.map(lambda l: l.split(","))
>>> people = parts.map(lambda p: Row(nameap[0],ageaint(p[l])))
>>> peopledf = spark.createDataFrame(people)

Specify Schema

>>> people = parts.map(lambda p: Row(name=p[0],
               age=int(p[1].strip())))
>>>  schemaString = "name age"
>>> fields = [StructField(field_name, StringType(), True) for field_name in schemaString.split()]
>>> schema = StructType(fields)
>>> spark.createDataFrame(people, schema).show()

 

From Spark Data Sources
JSON

>>>  df = spark.read.json("customer.json")
>>> df.show()

>>>  df2 = spark.read.load("people.json", format="json")

Parquet files

>>> df3 = spark.read.load("users.parquet")

TXT files

>>> df4 = spark.read.text("people.txt")

Filter 

#Filter entries of age, only keep those records of which the values are >24
>>> df.filter(df["age"]>24).show()

Duplicate Values 

>>> df = df.dropDuplicates()

Queries 
 

>>> from pyspark.sql import functions as F

Select

>>> df.select("firstName").show() #Show all entries in firstName column
>>> df.select("firstName","lastName") \
      .show()
>>> df.select("firstName", #Show all entries in firstName, age and type
              "age",
              explode("phoneNumber") \
              .alias("contactInfo")) \
      .select("contactInfo.type",
              "firstName",
              "age") \
      .show()
>>> df.select(df["firstName"],df["age"]+ 1) #Show all entries in firstName and age, .show() add 1 to the entries of age
>>> df.select(df['age'] > 24).show() #Show all entries where age >24

When

>>> df.select("firstName", #Show firstName and 0 or 1 depending on age >30
               F.when(df.age > 30, 1) \
              .otherwise(0)) \
      .show()
>>> df[df.firstName.isin("Jane","Boris")] #Show firstName if in the given options
.collect()

Like 

>>> df.select("firstName", #Show firstName, and lastName is TRUE if lastName is like Smith
              df.lastName.like("Smith")) \
     .show()

Startswith - Endswith 

>>> df.select("firstName", #Show firstName, and TRUE if lastName starts with Sm
              df.lastName \
                .startswith("Sm")) \
      .show()
>>> df.select(df.lastName.endswith("th"))\ #Show last names ending in th
      .show()

Substring 

>>> df.select(df.firstName.substr(1, 3) \ #Return substrings of firstName
                          .alias("name")) \
        .collect()

Between 

>>> df.select(df.age.between(22, 24)) \ #Show age: values are TRUE if between 22 and 24
          .show()

Add, Update & Remove Columns 

Adding Columns

 >>> df = df.withColumn('city',df.address.city) \
            .withColumn('postalCode',df.address.postalCode) \
            .withColumn('state',df.address.state) \
            .withColumn('streetAddress',df.address.streetAddress) \
            .withColumn('telePhoneNumber', explode(df.phoneNumber.number)) \
            .withColumn('telePhoneType', explode(df.phoneNumber.type)) 

Updating Columns

>>> df = df.withColumnRenamed('telePhoneNumber', 'phoneNumber')

Removing Columns

  >>> df = df.drop("address", "phoneNumber")
 >>> df = df.drop(df.address).drop(df.phoneNumber)
 

Missing & Replacing Values 
 

>>> df.na.fill(50).show() #Replace null values
 >>> df.na.drop().show() #Return new df omitting rows with null values
 >>> df.na \ #Return new df replacing one value with another
       .replace(10, 20) \
       .show()

GroupBy 

>>> df.groupBy("age")\ #Group by age, count the members in the groups
      .count() \
      .show()

Sort 
 

>>> peopledf.sort(peopledf.age.desc()).collect()
>>> df.sort("age", ascending=False).collect()
>>> df.orderBy(["age","city"],ascending=[0,1])\
     .collect()

Repartitioning 

>>> df.repartition(10)\ #df with 10 partitions
      .rdd \
      .getNumPartitions()
>>> df.coalesce(1).rdd.getNumPartitions() #df with 1 partition

Running Queries Programmatically 
 

Registering DataFrames as Views

>>> peopledf.createGlobalTempView("people")
>>> df.createTempView("customer")
>>> df.createOrReplaceTempView("customer")

Query Views

>>> df5 = spark.sql("SELECT * FROM customer").show()
>>> peopledf2 = spark.sql("SELECT * FROM global_temp.people")\
               .show()

Inspect Data 
 

>>> df.dtypes #Return df column names and data types
>>> df.show() #Display the content of df
>>> df.head() #Return first n rows
>>> df.first() #Return first row
>>> df.take(2) #Return the first n rows >>> df.schema Return the schema of df
>>> df.describe().show() #Compute summary statistics >>> df.columns Return the columns of df
>>> df.count() #Count the number of rows in df
>>> df.distinct().count() #Count the number of distinct rows in df
>>> df.printSchema() #Print the schema of df
>>> df.explain() #Print the (logical and physical) plans

Output

Data Structures 
 

 >>> rdd1 = df.rdd #Convert df into an RDD
 >>> df.toJSON().first() #Convert df into a RDD of string
 >>> df.toPandas() #Return the contents of df as Pandas DataFrame

Write & Save to Files 

>>> df.select("firstName", "city")\
       .write \
       .save("nameAndCity.parquet")
 >>> df.select("firstName", "age") \
       .write \
       .save("namesAndAges.json",format="json")

Stopping SparkSession 

>>> spark.stop()

Have this Cheat Sheet at your fingertips

Original article source at https://www.datacamp.com

#pyspark #cheatsheet #spark #dataframes #python #bigdata

Google's Flutter 1.20 stable announced with new features - Navoki

Flutter Google cross-platform UI framework has released a new version 1.20 stable.

Flutter is Google’s UI framework to make apps for Android, iOS, Web, Windows, Mac, Linux, and Fuchsia OS. Since the last 2 years, the flutter Framework has already achieved popularity among mobile developers to develop Android and iOS apps. In the last few releases, Flutter also added the support of making web applications and desktop applications.

Last month they introduced the support of the Linux desktop app that can be distributed through Canonical Snap Store(Snapcraft), this enables the developers to publish there Linux desktop app for their users and publish on Snap Store.  If you want to learn how to Publish Flutter Desktop app in Snap Store that here is the tutorial.

Flutter 1.20 Framework is built on Google’s made Dart programming language that is a cross-platform language providing native performance, new UI widgets, and other more features for the developer usage.

Here are the few key points of this release:

Performance improvements for Flutter and Dart

In this release, they have got multiple performance improvements in the Dart language itself. A new improvement is to reduce the app size in the release versions of the app. Another performance improvement is to reduce junk in the display of app animation by using the warm-up phase.

sksl_warm-up

If your app is junk information during the first run then the Skia Shading Language shader provides for pre-compilation as part of your app’s build. This can speed it up by more than 2x.

Added a better support of mouse cursors for web and desktop flutter app,. Now many widgets will show cursor on top of them or you can specify the type of supported cursor you want.

Autofill for mobile text fields

Autofill was already supported in native applications now its been added to the Flutter SDK. Now prefilled information stored by your OS can be used for autofill in the application. This feature will be available soon on the flutter web.

flutter_autofill

A new widget for interaction

InteractiveViewer is a new widget design for common interactions in your app like pan, zoom drag and drop for resizing the widget. Informations on this you can check more on this API documentation where you can try this widget on the DartPad. In this release, drag-drop has more features added like you can know precisely where the drop happened and get the position.

Updated Material Slider, RangeSlider, TimePicker, and DatePicker

In this new release, there are many pre-existing widgets that were updated to match the latest material guidelines, these updates include better interaction with Slider and RangeSliderDatePicker with support for date range and time picker with the new style.

flutter_DatePicker

New pubspec.yaml format

Other than these widget updates there is some update within the project also like in pubspec.yaml file format. If you are a flutter plugin publisher then your old pubspec.yaml  is no longer supported to publish a plugin as the older format does not specify for which platform plugin you are making. All existing plugin will continue to work with flutter apps but you should make a plugin update as soon as possible.

Preview of embedded Dart DevTools in Visual Studio Code

Visual Studio code flutter extension got an update in this release. You get a preview of new features where you can analyze that Dev tools in your coding workspace. Enable this feature in your vs code by _dart.previewEmbeddedDevTools_setting. Dart DevTools menu you can choose your favorite page embed on your code workspace.

Network tracking

The updated the Dev tools comes with the network page that enables network profiling. You can track the timings and other information like status and content type of your** network calls** within your app. You can also monitor gRPC traffic.

Generate type-safe platform channels for platform interop

Pigeon is a command-line tool that will generate types of safe platform channels without adding additional dependencies. With this instead of manually matching method strings on platform channel and serializing arguments, you can invoke native class and pass nonprimitive data objects by directly calling the Dartmethod.

There is still a long list of updates in the new version of Flutter 1.2 that we cannot cover in this blog. You can get more details you can visit the official site to know more. Also, you can subscribe to the Navoki newsletter to get updates on these features and upcoming new updates and lessons. In upcoming new versions, we might see more new features and improvements.

You can get more free Flutter tutorials you can follow these courses:

#dart #developers #flutter #app developed #dart devtools in visual studio code #firebase local emulator suite in flutter #flutter autofill #flutter date picker #flutter desktop linux app build and publish on snapcraft store #flutter pigeon #flutter range slider #flutter slider #flutter time picker #flutter tutorial #flutter widget #google flutter #linux #navoki #pubspec format #setup flutter desktop on windows

Terry  Tremblay

Terry Tremblay

1598396940

What is Flutter and why you should learn it?

Flutter is an open-source UI toolkit for mobile developers, so they can use it to build native-looking** Android and iOS** applications from the same code base for both platforms. Flutter is also working to make Flutter apps for Web, PWA (progressive Web-App) and Desktop platform (Windows,macOS,Linux).

flutter-mobile-desktop-web-embedded_min

Flutter was officially released in December 2018. Since then, it has gone a much stronger flutter community.

There has been much increase in flutter developers, flutter packages, youtube tutorials, blogs, flutter examples apps, official and private events, and more. Flutter is now on top software repos based and trending on GitHub.

Flutter meaning?

What is Flutter? this question comes to many new developer’s mind.

humming_bird_dart_flutter

Flutter means flying wings quickly, and lightly but obviously, this doesn’t apply in our SDK.

So Flutter was one of the companies that were acquired by **Google **for around $40 million. That company was based on providing gesture detection and recognition from a standard webcam. But later when the Flutter was going to release in alpha version for developer it’s name was Sky, but since Google already owned Flutter name, so they rename it to Flutter.

Where Flutter is used?

Flutter is used in many startup companies nowadays, and even some MNCs are also adopting Flutter as a mobile development framework. Many top famous companies are using their apps in Flutter. Some of them here are

Dream11

Dream11

NuBank

NuBank

Reflectly app

Reflectly app

Abbey Road Studios

Abbey Road Studios

and many more other apps. Mobile development companies also adopted Flutter as a service for their clients. Even I was one of them who developed flutter apps as a freelancer and later as an IT company for mobile apps.

Flutter as a service

#dart #flutter #uncategorized #flutter framework #flutter jobs #flutter language #flutter meaning #flutter meaning in hindi #google flutter #how does flutter work #what is flutter

How to Create a Responsive Dropdown Menu Bar with Search Field using HTML & CSS

In this guide you’ll learn how to create a Responsive Dropdown Menu Bar with Search Field using only HTML & CSS.

To create a responsive dropdown menu bar with search field using only HTML & CSS . First, you need to create two Files one HTML File and another one is CSS File.

1: First, create an HTML file with the name of index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Dropdown Menu with Search Box | Codequs</title>
  <link rel="stylesheet" href="style.css">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.3/css/all.min.css"/>
</head>
<body>
  <div class="wrapper">
    <nav>
      <input type="checkbox" id="show-search">
      <input type="checkbox" id="show-menu">
      <label for="show-menu" class="menu-icon"><i class="fas fa-bars"></i></label>
      <div class="content">
      <div class="logo"><a href="#">CodingNepal</a></div>
        <ul class="links">
          <li><a href="#">Home</a></li>
          <li><a href="#">About</a></li>
          <li>
            <a href="#" class="desktop-link">Features</a>
            <input type="checkbox" id="show-features">
            <label for="show-features">Features</label>
            <ul>
              <li><a href="#">Drop Menu 1</a></li>
              <li><a href="#">Drop Menu 2</a></li>
              <li><a href="#">Drop Menu 3</a></li>
              <li><a href="#">Drop Menu 4</a></li>
            </ul>
          </li>
          <li>
            <a href="#" class="desktop-link">Services</a>
            <input type="checkbox" id="show-services">
            <label for="show-services">Services</label>
            <ul>
              <li><a href="#">Drop Menu 1</a></li>
              <li><a href="#">Drop Menu 2</a></li>
              <li><a href="#">Drop Menu 3</a></li>
              <li>
                <a href="#" class="desktop-link">More Items</a>
                <input type="checkbox" id="show-items">
                <label for="show-items">More Items</label>
                <ul>
                  <li><a href="#">Sub Menu 1</a></li>
                  <li><a href="#">Sub Menu 2</a></li>
                  <li><a href="#">Sub Menu 3</a></li>
                </ul>
              </li>
            </ul>
          </li>
          <li><a href="#">Feedback</a></li>
        </ul>
      </div>
      <label for="show-search" class="search-icon"><i class="fas fa-search"></i></label>
      <form action="#" class="search-box">
        <input type="text" placeholder="Type Something to Search..." required>
        <button type="submit" class="go-icon"><i class="fas fa-long-arrow-alt-right"></i></button>
      </form>
    </nav>
  </div>
  <div class="dummy-text">
    <h2>Responsive Dropdown Menu Bar with Searchbox</h2>
    <h2>using only HTML & CSS - Flexbox</h2>
  </div>
</body>
</html>

2: Second, create a CSS file with the name of style.css

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@200;300;400;500;600;700&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  text-decoration: none;
  font-family: 'Poppins', sans-serif;
}
.wrapper{
  background: #171c24;
  position: fixed;
  width: 100%;
}
.wrapper nav{
  position: relative;
  display: flex;
  max-width: calc(100% - 200px);
  margin: 0 auto;
  height: 70px;
  align-items: center;
  justify-content: space-between;
}
nav .content{
  display: flex;
  align-items: center;
}
nav .content .links{
  margin-left: 80px;
  display: flex;
}
.content .logo a{
  color: #fff;
  font-size: 30px;
  font-weight: 600;
}
.content .links li{
  list-style: none;
  line-height: 70px;
}
.content .links li a,
.content .links li label{
  color: #fff;
  font-size: 18px;
  font-weight: 500;
  padding: 9px 17px;
  border-radius: 5px;
  transition: all 0.3s ease;
}
.content .links li label{
  display: none;
}
.content .links li a:hover,
.content .links li label:hover{
  background: #323c4e;
}
.wrapper .search-icon,
.wrapper .menu-icon{
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  line-height: 70px;
  width: 70px;
  text-align: center;
}
.wrapper .menu-icon{
  display: none;
}
.wrapper #show-search:checked ~ .search-icon i::before{
  content: "\f00d";
}
.wrapper .search-box{
  position: absolute;
  height: 100%;
  max-width: calc(100% - 50px);
  width: 100%;
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s ease;
}
.wrapper #show-search:checked ~ .search-box{
  opacity: 1;
  pointer-events: auto;
}
.search-box input{
  width: 100%;
  height: 100%;
  border: none;
  outline: none;
  font-size: 17px;
  color: #fff;
  background: #171c24;
  padding: 0 100px 0 15px;
}
.search-box input::placeholder{
  color: #f2f2f2;
}
.search-box .go-icon{
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  line-height: 60px;
  width: 70px;
  background: #171c24;
  border: none;
  outline: none;
  color: #fff;
  font-size: 20px;
  cursor: pointer;
}
.wrapper input[type="checkbox"]{
  display: none;
}
/* Dropdown Menu code start */
.content .links ul{
  position: absolute;
  background: #171c24;
  top: 80px;
  z-index: -1;
  opacity: 0;
  visibility: hidden;
}
.content .links li:hover > ul{
  top: 70px;
  opacity: 1;
  visibility: visible;
  transition: all 0.3s ease;
}
.content .links ul li a{
  display: block;
  width: 100%;
  line-height: 30px;
  border-radius: 0px!important;
}
.content .links ul ul{
  position: absolute;
  top: 0;
  right: calc(-100% + 8px);
}
.content .links ul li{
  position: relative;
}
.content .links ul li:hover ul{
  top: 0;
}
/* Responsive code start */
@media screen and (max-width: 1250px){
  .wrapper nav{
    max-width: 100%;
    padding: 0 20px;
  }
  nav .content .links{
    margin-left: 30px;
  }
  .content .links li a{
    padding: 8px 13px;
  }
  .wrapper .search-box{
    max-width: calc(100% - 100px);
  }
  .wrapper .search-box input{
    padding: 0 100px 0 15px;
  }
}
@media screen and (max-width: 900px){
  .wrapper .menu-icon{
    display: block;
  }
  .wrapper #show-menu:checked ~ .menu-icon i::before{
    content: "\f00d";
  }
  nav .content .links{
    display: block;
    position: fixed;
    background: #14181f;
    height: 100%;
    width: 100%;
    top: 70px;
    left: -100%;
    margin-left: 0;
    max-width: 350px;
    overflow-y: auto;
    padding-bottom: 100px;
    transition: all 0.3s ease;
  }
  nav #show-menu:checked ~ .content .links{
    left: 0%;
  }
  .content .links li{
    margin: 15px 20px;
  }
  .content .links li a,
  .content .links li label{
    line-height: 40px;
    font-size: 20px;
    display: block;
    padding: 8px 18px;
    cursor: pointer;
  }
  .content .links li a.desktop-link{
    display: none;
  }
  /* dropdown responsive code start */
  .content .links ul,
  .content .links ul ul{
    position: static;
    opacity: 1;
    visibility: visible;
    background: none;
    max-height: 0px;
    overflow: hidden;
  }
  .content .links #show-features:checked ~ ul,
  .content .links #show-services:checked ~ ul,
  .content .links #show-items:checked ~ ul{
    max-height: 100vh;
  }
  .content .links ul li{
    margin: 7px 20px;
  }
  .content .links ul li a{
    font-size: 18px;
    line-height: 30px;
    border-radius: 5px!important;
  }
}
@media screen and (max-width: 400px){
  .wrapper nav{
    padding: 0 10px;
  }
  .content .logo a{
    font-size: 27px;
  }
  .wrapper .search-box{
    max-width: calc(100% - 70px);
  }
  .wrapper .search-box .go-icon{
    width: 30px;
    right: 0;
  }
  .wrapper .search-box input{
    padding-right: 30px;
  }
}
.dummy-text{
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100%;
  z-index: -1;
  padding: 0 20px;
  text-align: center;
  transform: translate(-50%, -50%);
}
.dummy-text h2{
  font-size: 45px;
  margin: 5px 0;
}

Now you’ve successfully created a Responsive Dropdown Menu Bar with Search Field using only HTML & CSS.

Corey Brooks

Corey Brooks

1657254050

Top 9+ Common CSS Mistakes To Avoid

In this tutorial, we'll summarise what the top 9+ CSS mistakes are and how to avoid them.

Top 9+ Common CSS Mistakes To Avoid

It’s easy to get tripped up with CSS. Here are some common CSS mistakes we all make.

1. Not Using a Proper CSS Reset

Web browsers are our fickle friends. Their inconsistencies can make any developer want to tear their hair out. But at the end of the day, they’re what will present your website, so you better do what you have to do to please them.

One of the sillier things browsers do is provide default styling for HTML elements. I suppose you can’t really blame them: what if a “webmaster” chose not to style their page? There has to be a fallback mechanism for people who choose not to use CSS.

In any case, there’s rarely a case of two browsers providing identical default styling, so the only real way to make sure your styles are effective is to use a CSS reset. What a CSS reset entails is resetting (or, rather, setting) all the styles of all the HTML elements to a predictable baseline value. The beauty of this is that once you include a CSS reset effectively, you can style all the elements on your page as if they were all the same to start with.

It’s a blank slate, really. There are many CSS reset codebases on the web that you can incorporate into your work. I personally use a modified version of the popular Eric Meyer reset and Six Revisions uses a modified version of YUI Reset CSS.

You can also build your own reset if you think it would work better. What many of us do is utilizing a simple universal selector margin/padding reset.

* { margin:0; padding:0; } 

Though this works, it’s not a full reset.

You also need to reset, for example, borders, underlines, and colors of elements like list items, links, and tables so that you don’t run into unexpected inconsistencies between web browsers. Learn more about resetting your styles via this guide: Resetting Your Styles with CSS Reset.

2. Over-Qualifying Selectors

Being overly specific when selecting elements to style is not good practice. The following selector is a perfect example of what I’m talking about:

ul#navigation li a { ... } 

Typically the structure of a primary navigation list is a <ul> (usually with an ID like #nav or #navigation) then a few list items (<li>) inside of it, each with its own <a> tag inside it that links to other pages.

This HTML structure is perfectly correct, but the CSS selector is really what I’m worried about. First things first: There’s no reason for the ul before #navigation as an ID is already the most specific selector. Also, you don’t have to put li in the selector syntax because all the a elements inside the navigation are inside list items, so there’s no reason for that bit of specificity.

Thus, you can condense that selector as:

#navigation a { ... } 

This is an overly simplistic example because you might have nested list items that you want to style differently (i.e. #navigation li a is different from #navigation li ul li a); but if you don’t, then there’s no need for the excessive specificity.

I also want to talk about the need for an ID in this situation. Let’s assume for a minute that this navigation list is inside a header div (#header). Let us also assume that you will have no other unordered list in the header besides the navigation list.

If that is the case, we can even remove the ID from the unordered list in our HTML markup, and then we can select it in CSS as such:

#header ul a { ... } 

Here’s what I want you to take away from this example: Always write your CSS selectors with the very minimum level of specificity necessary for it to work. Including all that extra fluff may make it look more safe and precise, but when it comes to CSS selectors, there are only two levels of specificity: specific, and not specific enough.

3. Not Using Shorthand Properties

Take a look at the following property list:

#selector { margin-top: 50px; margin-right: 0; margin-bottom: 50px; margin-left 0; }

What is wrong with this picture? I hope that alarm bells are ringing in your head as you notice how much we’re repeating ourselves. Fortunately, there is a solution, and it’s using CSS shorthand properties.

The following has the same effect as the above style declaration, but we’ve reduced our code by three lines.

#selector { margin: 50px 0; }

Check out this list of properties that deals with font styles:

font-family: Helvetica; font-size: 14px; font-weight: bold; line-height: 1.5;

We can condense all that into one line:

font: bold 14px/1.5 Helvetica; 

We can also do this for background properties. The following:

background-image: url(background.png); background-repeat: repeat-y; background-position: center top;

Can be written in shorthand CSS as such:

background: url(background.png) repeat-y center top; 

4. Using 0px instead of 0

Say you want to add a 20px margin to the bottom of an element. You might use something like this:

#selector { margin: 20px 0px 20px 0px; } 

Don’t. This is excessive.

There’s no need to include the px after 0. While this may seem like I’m nitpicking and that it may not seem like much, when you’re working with a huge file, removing all those superfluous px can reduce the size of your file (which is never a bad thing).

5. Using Color Names Instead of Hexadecimal

Declaring red for color values is the lazy man’s #FF0000. By saying:

color: red;

You’re essentially saying that the browser should display what it thinks red is. If you’ve learned anything from making stuff function correctly in all browsers — and the hours of frustration you’ve accumulated because of a stupid list-bullet misalignment that can only be seen in IE7 — it’s that you should never let the browser decide how to display your web pages.

Instead, you should go to the effort to find the actual hex value for the color you’re trying to use. That way, you can make sure it’s the same color displayed across all browsers. You can use a color cheatsheet that provides a preview and the hex value of a color.

This may seem trivial, but when it comes to CSS, it’s the tiny things that often lead to the big gotchas.

6. Redundant Selectors

My process for writing styles is to start with all the typography, and then work on the structure, and finally on styling all the colors and backgrounds. That’s what works for me. Since I don’t focus on just one element at a time, I commonly find myself accidentally typing out a redundant style declaration.

I always do a final check after I’m done so that I can make sure that I haven’t repeated any selectors; and if I have, I’ll merge them. This sort of mistake is fine to make while you’re developing, but just try to make sure they don’t make it into production.

7. Redundant Properties

Similar to the one above, I often find myself having to apply the same properties to multiple selectors. This could be styling an <h5> in the header to look exactly like the <h6> in the footer, making the <pre>‘s and <blockquote>‘s the same size, or any number of things in between. In the final review of my CSS, I will look to make sure that I haven’t repeated too many properties.

For example, if I see two selectors doing the same thing, such as this:

#selector-1 { font-style: italic; color: #e7e7e7; margin: 5px; padding: 20px } .selector-2 { font-style: italic; color: #e7e7e7; margin: 5px; padding: 20px }

I will combine them, with the selectors separated by a comma (,):

#selector-1, .selector-2 { font-style: italic; color: #e7e7e7; margin: 5px; padding: 20px }

I hope you’re seeing the trend here: Try to be as terse and as efficient as possible. It pays dividends in maintenance time and page-load speed.

8. Not Providing Fallback Fonts

In a perfect world, every computer would always have every font you would ever want to use installed. Unfortunately, we don’t live in a perfect world. @font-face aside, web designers are pretty much limited to the few so called web-safe fonts (e.g.

Arial, Georgia, serif, etc.). There is a plus side, though. You can still use fonts like Helvetica that aren’t necessarily installed on every computer.

The secret lies in font stacks. Font stacks are a way for developers to provide fallback fonts for the browser to display if the user doesn’t have the preferred font installed. For example:

#selector { font-family: Helvetica; }

Can be expanded with fallback fonts as such:

#selector { font-family: Helvetica, Arial, sans-serif; }

Now, if the user doesn’t have Helvetica, they can see your site in Arial, and if that doesn’t work, it’ll just default to any sans-serif font installed.

By defining fallback fonts, you gain more control as to how your web pages are rendered.

9. Unnecessary Whitespace

When it comes to trying to reduce your CSS file sizes for performance, every space counts. When you’re developing, it’s OK to format your code in the way that you’re comfortable with. However, there is absolutely no reason not to take out excess characters (a process known as minification) when you actually push your project onto the web where the size of your files really counts.

Too many developers simply don’t minify their files before launching their websites, and I think that’s a huge mistake. Although it may not feel like it makes much of a difference, when you have huge CSS files

10. Not Organizing Your CSS in a Logical Way

When you’re writing CSS, do yourself a favor and organize your code. Through comments, you can insure that the next time you come to make a change to a file you’ll still be able to navigate it. 

I personally like to organize my styles by how the HTML that I’m styling is structured. This means that I have comments that distinguish the header, body, sidebar, and footer. A common CSS-authoring mistake I see is people just writing up their styles as soon as they think of them.

The next time you try to change something and can’t find the style declaration, you’ll be silently cursing yourself for not organizing your CSS well enough.

11. Using Only One Stylesheet for Everything

This one’s subjective, so bear with me while I give you my perspective. I am of the belief, as are others, that it is better to split stylesheets into a few different ones for big sites for easier maintenance and for better modularity. Maybe I’ll have one for a CSS reset, one for IE-specific fixes, and so on.

By organizing CSS into disparate stylesheets, I’ll know immediately where to find a style I want to change. You can do this by importing all the stylesheets into a stylesheet like so:

@import url("reset.css"); @import url("ie.css"); @import url("typography.css"); @import url("layout.css"); 

Let me stress, however, that this is what works for me and many other developers. You may prefer to squeeze them all in one file, and that’s okay; there’s nothing wrong with that.

But if you’re having a hard time maintaining a single file, try splitting your CSS up.

12. Not Providing a Print Stylesheet

In order to style your site on pages that will be printed, all you have to do is utilize and include a print stylesheet. It’s as easy as:

<link rel="stylesheet" href="print.css" media="print" /> 

Using a stylesheet for print allows you to hide elements you don’t want printed (such as your navigation menu), reset the background color to white, provide alternative typography for paragraphs so that it’s better suited on a piece of paper, and so forth. The important thing is that you think about how your page will look when printed.

Too many people just don’t think about it, so their sites will simply print the same way you see them on the screen.


I Made These 2 BEGINNER CSS Mistakes

No matter how long you've been writing code, it's always a good time to revisit the basics. While working on a project the other day, I made 2 beginner mistakes with the CSS I was writing. I misunderstood both CSS specificity and how transform:scale affects the DOM!

Stack Overflow about transform:scale - https://stackoverflow.com/questions/32835144/css-transform-scale-does-not-change-dom-size 
CSS Specificity - https://www.w3schools.com/css/css_specificity.asp 

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