How to manipulate (create, read, update, and delete) cookies with JS

How to manipulate (create, read, update, and delete) cookies with JS

How to manipulate cookies with JavaScript? In this article, I will introduce the methods of manipulating (creating, reading, updating and deleting) cookies with JavaScript.

How to manipulate cookies with JavaScript? In this article, I will introduce the methods of manipulating (creating, reading, updating and deleting) cookies with JavaScript. There is a certain reference value, friends in need can refer to it, I hope to help everyone.

Introduction

Web servers and HTTP servers are stateless, so when a web server sends a web page to a browser, the connection is cut off and the server forgets about everything related to the user.

How can the browser and web server remember information about the user? Cookies were invented to solve this problem.

When a user comes to a web page, their name, unique id, or any other information can be stored in a cookie in their browser.

And the next time the user comes back to the webpage, the cookie will remember their name or unique id.

Cookies are simply small text files of data that are stored in your computer's browser. They contain this data:

  • Name-value pair with actual data
  • Expiry date for when the cookie becomes invalid
  • Domain and path of the server it should be sent to

And cookies also have some limitations that are worth mentioning:

  • Maximum size of 4096 Bytes per individual cookie
  • Maximum of 20 cookies per domain (this is slightly different for each browser)
  • Cookies are private to its own domain (a site cannot read other domain's cookies, only it's own)
  • Size limits apply to the entire cookie, not just its value

In the browser, cookies are exposed via the document object as document.cookies.

In the sections below, we'll go over how to set, get, update, and delete cookie data in your browser using JavaScript.

Let's get started!

table of Contents

  • Create Cookies
  • Read Cookies
  • Update Cookies
  • Delete Cookies

Create Cookies

Setting cookies in your browser with JavaScript is easy! I will show you below.

Setting cookies

Here is the execution code to create a new cookie with JavaScript in the browser:

document.cookie = "userId = nick123"

After running this code, open your browser and you should be able to find the cookie in Application (Safari or Chrome) or Storage (Firefox) in the developer tools.

Set cookie expiration time

You can also add an expiration time (UTC) to the cookie to tell the browser when it should be deleted:

document.cookie = "userId = nick123; expires = Wed, 15 Jan 2020 12:00:00 UTC"

Set a cookie path

You can also tell the browser where the cookie belongs (the default is the path of the current page):

document.cookie = "userId = nick123; expires = Wed, 15 Jan 2020 12:00:00 UTC; 
 path = / user"
 

Setting the cookie domain

The last piece of data we will cover is the domain to which the cookie belongs (defaults to the current domain):

document.cookie = "userId = nick123; expires = Wed, 15 Jan 2020 12:00:00 UTC; 
 path = / user; domain = mysite.com"

Read Cookies

By document.cookiesubject, read cookie with JavaScript is also very simple:

Read all cookies on a single page

Get all cookies for a single page as strings, each cookie separated by a semicolon:

const cookies = document.cookie

Read cookies with a specific name

To access a cookie with a specific name, we need to get all the cookies on the page, parse the string, and find a match for the cookie name we want to find.

This is a function that does this with a regular expression:

function getCookieValue (name) { 
  let result = document.cookie.match ("(^ | [^;] +) \\ s *" + name + "\\ s * = \\ s * ([^;] +) ") 
  return result? result.pop ():" " 
}

You use the function like this:

getCookieValue ("userId") // returns nick123

This returns the function provided to the namestring value corresponding to the parameters.

If you haven't mastered regular expressions yet, there is another function that does the same thing:

function getCookieValue (name) { 
  const nameString = name + "=" 
  
  const value = document.cookie.split (";"). filter (item => { 
    return item.includes (nameString) 
  }) 
  
  if (value.length) { 
    return value [0] .substring (nameString.length, value [0] .length) 
  } else { 
    return "" 
  } 
}

Use the function in the same way:

getCookieValue ("userId") // returns nick123

Update Cookies

You can change the value of a cookie by creating it by overwriting it with a new value.

You can use this code to override the cookie "userId" created earlier in this article :

document.cookie = "userId = new_value"

When you run again getCookieValuewhen the function will return the new value:

getCookieValue ("userId") // returns new_value

Delete Cookies

You can delete cookies by setting a cookie with an empty value and setting its expiration date to any time in the past.

If we want to delete the cookie "userId" from the previous example , follow these steps:

document.cookie = "userId =; expires = Thu, 01 Jan 1970 00:00:00 UTC;"

Is it simple?

What are the differences between the various JavaScript frameworks? E.g. Vue.js, Angular.js, React.js

What are the differences? Do they each have specific use contexts?

What are the differences? Do they each have specific use contexts?

Ember.js vs Vue.js - Which is JavaScript Framework Works Better for You

Ember.js vs Vue.js - Which is JavaScript Framework Works Better for You

In this article we will discuss full details and comparison of both Ember.js and Vue.js

JavaScript was initially created to work for web applications. But today they have become the favorite of mobile app developers. Most of the developers prefer to work with frameworks based on JavaScript. It simplifies coding. You can use JavaScript with almost any framework.

The use of a particular framework will decide how easy and fast it is to create the app. So, you must choose the best one suited for the app that you are planning to build. You must make a wise choice so that you benefit in the end. Among the crowded market, two of the frameworks stand out. We will make a comparison between Ember.js and Vue.js.

Why Do You Select A Particular Framework?

Before we start comparing the two frameworks, we should understand the factors that lead to the choice of a framework. Each developer chooses a framework before he or she goes to work on an app. Let us see the reasons for the selection.

● The codes must be easy to understand and transparent.

● The framework should give the maximum power with the least amount of coding.

● The framework should provide a well laid out structure to work on.

● Does the framework support an in-built router or an external plug-in router?

● The framework should be able to transfer more data on a full page-load so that it becomes a single-page app. A single-page app is more beneficial for the application.

● In single page architectures if there is a need for users to share links to sub-screens within the interface, then the framework should have the capacity to route based on the URL.

● A tighter template option can help in enabling two-way binding.

● The framework should not conflict any third-party library.

● Testing the codes inside the framework should be easy.

● The framework should provide the HTTP client service for AJAX calls

● The documentation is essential. It should be complete and up-to-date.

● The framework should be compatible with the latest version of the browser.

● The framework has to fulfill the above conditions for easy construction of the app. You must ensure that the framework you choose meets the conditions.

Vue.js Explained

Developers are always looking at new frameworks to build their apps. The main requirements are speed and low cost. The framework should be easy to use by even new developers. You should be able to use it at low cost. Other considerations are about simple coding, proper documentation, etc.

Vue.js combines a lot of good when it comes to software language for web app development. The architecture of Vue.js is easy to put in use. The apps developed using Vue.js are easy to integrate with new apps.

Vue.js is a very lightweight framework. It makes it fast to download. It is also much faster than other frameworks. The single-file component nature of the framework is also beneficial. The size has made it very popular.

You can further decrease weight. With Vue.js you can separate the template-to-virtual DOM and compiler. You can only deploy the minified and zipped interpreter which is only 12 KB. You can compile the templates in your machine.

Another significant advantage of Vue.js is that it can integrate easily with existing applications created with JavaScript. It will make it easy for using this framework to make changes to applications already present.

Vue.js also integrates easily with other front-end libraries. You can plug in another library and make up for any deficiency in this framework. This feature makes this tool a versatile one.

Vue.js uses the method of rendering on the streaming-side server. You can render your component and get a readable stream. You can then send this to the HTTP server. It makes the server highly responsive. Your users will get the rendered content very quickly.

Vue.js is very SEO friendly. As the framework supports server-side rendering, the views are rendered directly on the server. The search engines list these.

But the most important thing for you is the ease with which you can learn Vue.js. The structure is elementary. Even new developers will find it easy to use it to build their apps. This framework helps in developing both small and large templates. It helps to save a lot of time.

You can go back and check your errors very easily. You can travel back and inspect all the states apart from testing your components. It is another important feature as far as any developer is concerned.

Vue.js also has very detailed documentation. It helps in writing your applications very quickly. You can build a web page or app with the basic knowledge of HTML or JavaScript.

● Vue.js has pure architecture. It helps in integration with other apps

● Vue.js is lightweight and fast. It can be made lighter by deploying only the interpreter

● You can separate the compiler and the template-to-virtual DOM.

● Due to smooth integration, you can use this to make changes to existing apps

● To make up for any shortfall, you can plug-in any library and makeup.

● As Vue.js uses streaming-side server rendering, your users can get quick responses.

● The server-side rendering also helps in being ranked higher by search engines.

● It has a simple structure. Easy to use for any new developer

● You can go back and check and correct your errors.

● You can check all the existing states.

● Detail documentation also helps build the web page or application very quickly.

Ember.js Decoded

Ember.js is an MVVM model framework. It is open-source software. This platform is mostly used for creating complex multi-page applications. It maintains up-to-date features without discarding any of the old features.

With this framework, you have to follow the architecture of the framework strictly. The JS framework is very tightly organized. It reduces the flexibility that other frameworks might offer.

There is a very refined and developed control system for its platforms and tools. You can integrate it with the new version with the tools provided. There is strict guidance about avoiding outdated APIs.

You can understand Ember’s APIs easily. They are also easy to work. You can make use of highly complex functionalities simply and straightforwardly.

The performance is better as similar jobs are processed together. It creates batches of similar bindings and DOM updates to improve the performance. It means that the browser needs to process them in one go. It will avoid recomputing for each task, wasting a lot of time.

You can write the codes in a simple manner and modules. You can use any of Ember’s APIs. It is possible due to the presence of Promises everywhere.

Ember comes with a well-written guide. The API is recorded in a useful manner. It is a front-end framework that is loaded. Ember has a router, pipeline, services, etc. of its own.

The basis for views, controllers, models, and framework is the Ember Object Model. All components come from the same objects. The framework is firm and steady. The reason is that all elements have similar jobs and characteristics.

Ember has made the general application, organization, and structure clear so that you don’t make any mistakes. You will have no chance to complicate the application unnecessarily. If you have to go out of the defined limits, you will have to force your way out.

The language used for templating in Embers is Handlebars. This language helps Embers to keep its logic out of view. The clean syntax of Handlebars makes it easy for you to read and understand the templates. Handlebar templates are faster to load.

Another advantage you gain from Handlebar is that you don’t have to update your template every time you add or remove data from the page. It will be done automatically by the language itself.

A community that is continually improving the framework supports Ember. They are updating the framework with the latest technology. They also make sure that backward compatibility is possible.

● Ember.js is an open-source MVVM model framework suitable for complex multiple-page applications.

● It offers both the latest and old features.

● It has a very tightly structured framework which doesn’t offer much flexibility

● A very refined control system helps you to integrate with new versions without any problem.

● There is strict guidance about avoiding outdated API versions.

● Ember’s APIs help you to use complex functionalities in a simple manner

● There is no recomputing for each task as the framework allows the browser to do similar functions together.

● Promises allow you to write modular and straightforward code using any API of Ember.js.

● Ember.js is a fully loaded, front-end framework.

● The framework is stable because all components have the same functionalities and properties.

● It has well-defined limitations which will prevent your complicating your application

● Handlebars, the language used by Ember.js allows you to read and understand templates easily. It also helps to load the templates faster.

● Handlebars will ensure to update the template every time you add or remove data.

● Ember.js has an active community that updates the framework regularly and facilitates backward compatibility.

A Comparison Between Ember.js And Vue.js

This article intends to compare the features of both frameworks. Let us see how the characteristics of these frameworks compare. It will help you to make use of the right framework for your web application.

When you need a modern engine for an old application, it is Vue.js which will help you. It combines the best properties of other frameworks. Vue.js is a developing framework. A ready-to-use library of interface elements does not exist. However, many third-party libraries can help you.

Ember.js offers you a well-organized and trustworthy framework. When the development team is big, this is the framework that suits best. It allows everyone to understand the written code and contribute to a common project. The technology will be up-to-date, and the platform will be stable.

Vue.js can help you use the syntax of different kinds. It helps in writing the codes with ease. It is also an SEO friendly framework. Ember is a fully loaded front-end framework and can help you develop the applications very fast. But it is not suitable for developing small projects.

It is not easy to say this is better than that. It will depend on what kind of project you have undertaken. Both have their pluses and minuses. The below table will help in a better comparison.

Final Thoughts

It is not easy to conclude as to which is better. It all depends on the application that you want to develop. Both frameworks are developing. Both are getting updates. Both the communities are working on the frameworks.

While Vue.js is more comfortable for writing codes, Ember is a full-stack framework allowing the development of apps very fast. It is suitable for big projects. It is too complicated to be used for smaller projects.

We hope you had a great time reading this article. If you’ve any questions or suggestions related to this blog, then feel free to ask them in the comment section. Thank You.!