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12/24/2020 Comments

Angular Reactive Forms: Display error messages onSubmit

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source: unsplash.com
The form validations play a significant role in web applications that have heavy forms. With validations, we achieve two things:
  • Establish communication with the end-user
  • Data integrity on the server. 
We know that complex business cases require different handling. Some application forms need to update the form model on the submit event, and some others require to display the error messages when the submit button is clicked.
​In this article, we will see both.

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10/28/2020 Comments

State Management and the washing machine

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image from unsplash
I will start this article by saying that  State Management is not easy.

You might think "c'mon, state management is just a bucket that holds data. Not a biggie". And yes, I....agree(?) It's a bucket that we have to split in slices, to think what data to add and in which slice, how and when to get data from the slice, how to deal with the side effects, how to construct the actions and the functions that handles those actions, aka reducers. Well, it seems that it's not that easy after all.

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10/9/2020 Comments

lazy load Angular components in a HOC

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image from unsplash
A great feature that Angular has is to dynamically load component in a Higher Order Component by using the ComponentFactoryResolver. Apart from this, we can also lazy load a component using ES6 import. 


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7/6/2020 Comments

Mind your imports and save the bundle size

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Did you know that a wrong SCSS usage can increase the bundle size of your Angular application? And you know what this issue is, right? A performance issue!! The bigger the bundle size the more time the browser requires to download all the files and the more time it takes to paint the page. 

A side note here: The CSS is render blocking which means that the browser won't render anything until all the CSS is downloaded and the CSSOM is constructed. 

Having this in mind, we have to take extra care of our CSS. Don't we? :) 

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12/16/2019 Comments

Angular - Custom Form Elements

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Photo by Eugen Str on Unsplash
The majority of the products I worked on was/is B2B and they consisted of many (MANY) web forms. You know how this goes.
  • You have to create the form model in the component (especially if you use reactive forms)
  • Create the HTML elements
  • Create the HTML elements
  • ...
  • Create the HTML elements
Those HTML elements more or less have a wrapper <div> element, a <label> tag, an <input> field, elements for error messages. This goes on and on. 

Who is our best friend for situations like this? ctrl+c & ctrl+v :) Yeah I know. I've been there.

Someone might say that this "best friend" helps us in many different cases. Here a bell rings. What do you do when you have to re-use the same code again and again? The answer is Abstraction. 
​

You know how to abstract your code in JS, in TS in C# and in many other languages. What about HTML though? Continue reading to find this out :) 

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5/13/2019 Comments

Ionic - use Angular CLI environments on build

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Developing an application in Angular CLI is really fun and fast due to its nature and the features it offers to developers.  One of the great features it has, is the ability to run your code using different variables. Similar to environmental variables that are distinguish per se. But what are the environment variables and what is the relation with the ionic?

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12/26/2018 Comments

Component communication with exportAs property


Have you ever had the need two components to communicate each other? Of course you had!

I bet that when you hear components communication or components interaction, you automatically think of @input @output decorators. 

Say that we have two components, parent and child. You want the parent component to interpolate on its template a property from the child component. How can we do this?
​
  1. Make use of @output decorator.
    When the child emits an event, the parent will handle this, take the event arguments, assign the value on a another variable, and finally use that variable on the template interpolation. You don't say that is a short way :)

  2. Make use of @viewChild

  3. Make use of exportAs

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11/9/2018 Comments

Smart dumb pattern in nested reactive forms

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source: https://www.cinemablend.com
In this post we will try together to build a form consisted of different components and we will try various implementations to achieve the best architecture. The final pattern that we will implement is the smart dumb.

We will try 4 different approaches and soon I will create a 5th one which will use the exportAs. 
The post is quite long but it worth's diving in :)

Our form will have:
  1. Wrapper component (smart)
  2. Basic info component (dumb)
  3. Address component (dumb)
  4. Credit Cards component (dumb)
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11/2/2018 Comments

Separate protractor config for CI server

The protractor.conf.js file is meant to offer a configuration for our e2e tests. The default which come with each new angular-cli app is very good and works really well. We shouldn't extend it unless we expect more.

Although it works well on localhost, what about the CI server?

On this post I wont explain what kind of configuration you might need for your CI, but how to separate the configuration and how to use it

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9/30/2018 Comments

Form select elements in angular

As web developers we have been developing web forms almost on every app. How many times have you spent time searching on google (or bing - no offense ) on finding solutions to pre-select an option on a select control while using angular? Yeah I know! Many times. And when you read the solution you are like "Ohh yess!"
Let's demystify this

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    I am a senior software engineer who loves scuba diving and hiking. A dog type person who owns two cats

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    All Angular Angularjs General Graphql Ionic Javascript .net Nodejs Typescript

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