Ionic 3 to Ionic 4 SCSS migration - ionic-framework

Question

Lately I am trying to migrate my Ionic 3 project to Ionic 4. Most of the migration is going successful but I keep having problems with my styling.
After some reading I changed a few things to my styling, listed below:
Moved global styling from app.scss to global.scss
Changed theme styling $colors for example to :root { ion-color- ... }
Changed naming of (some) components (ion-navbar to ion-toolbar, button to ion-button, etc.)
Removed page selectors in page-specific styling (so removed page-login { ... } in login.scss)
Though the styling is still not quite right. I am probably still missing some things.
As example I am using my page-specific style for my login page.
In Ionic 3 the style file looked as follows for this page:
page-login {
.content {
background: url('../assets/img/background.png') no-repeat;
background-size: cover;
#logo {
padding-top: 5rem;
}
form {
position: absolute;
bottom: 0;
width: 100%;
.logo-row {
margin-bottom: 40%;
}
.form-inputs {
.label-ios {
width: 60px;
max-width: 60px;
}
ion-icon, .select-ios, ::-webkit-input-placeholder {
color: color($colors, lightGray);
max-width: 100%;
}
.item-ios {
background: transparent;
padding-left: 0;
&:first-child {
border-top: none;
}
.input-wrapper {
padding-left: 50px;
input.text-input.text-input-ios {
color: color($colors, lightGray);
}
}
}
[icon-only] ion-icon {
line-height: 1;
}
}
}
}
}
In my Ionic 4 app I changed it to the following:
ion-content {
--background: url('../../../assets/img/background.png') no-repeat;
--background-size: cover;
#logo {
padding-top: 5rem;
}
ion-form {
--position: absolute;
--bottom: 0;
--width: 100%;
.logo-row {
margin-bottom: 40%;
}
ion-inputs {
.ios ion-label {
--width: 60px;
--max-width: 60px;
}
ion-icon, .select-ios, ::-webkit-input-placeholder {
--color: var(--ion-color-lightGray); //color($colors, lightGray);
--max-width: 100%;
}
.ios ion-item {
--background: transparent;
--padding-left: 0;
&:first-child {
--border-top: none;
}
.input-wrapper {
--padding-left: 50px;
input.text-input.text-input-ios {
--color: var(--ion-color-lightGray); //color($colors, lightGray);
}
}
}
[icon-only] ion-icon {
--line-height: 1;
}
}
}
}
There are a few things which are not styled correctly:
I thought I had to replace the most Ion specific components with ion- in front of it, for content this seems to work but the form targeting this does not seem to work (ion-form), while form (liek it used to be) also doesn't work. Any clues with what I should replace this? Or should I omit the form targeting and just keep it in ion-content?
There is also some html inline styling going on, I don't know if all these styles are still correctly used in Ionic 4? For example, I have read somewhere that I should replace padding text-center with class="ion-padding ion-text-center" but what about the inline col-x and offset-x styles?
My Ionic html login page looks as following:
<ion-header [ngClass]="'no-shadow'">
<ion-toolbar transparent>
<ion-buttons start>
<button ion-button icon-only menuToggle>
<ion-icon name="menu"></ion-icon>
</button>
</ion-buttons>
</ion-toolbar>
</ion-header>
<ion-content>
<ion-row class="logo-row" *ngIf="isKeyboardHidden">
<ion-col col-8 offset-2 class="ion-padding ion-text-center">
<img id="logo" src="assets/img/logo-dia-positive.png">
</ion-col>
</ion-row>
<form #f="ngForm" (ngSubmit)="onSubmit()">
<ion-row>
<ion-col>
<p style="height: 16px"></p>
</ion-col>
</ion-row>
<ion-list no-lines class="form-inputs">
<ion-item>
<ion-label icon-only>
<ion-icon name="person"></ion-icon>
</ion-label>
<ion-input
type="text"
name="username"
[(ngModel)]="account.username"
[placeholder]="'USERNAME' | translate"
required></ion-input>
</ion-item>
<ion-item>
<ion-label icon-only>
<ion-icon name="unlock"></ion-icon>
</ion-label>
<ion-input
type="password"
name="password"
[(ngModel)]="account.password"
[placeholder]="'PASSWORD' | translate"
required></ion-input>
</ion-item>
</ion-list>
<ion-row>
<ion-col col-10 offset-1>
<ion-button
block
[disabled]="!f.valid || isLoading">
{{'LOGIN' | translate}}
</ion-button>
</ion-col>
</ion-row>
</form>
</ion-content>
<ion-footer *ngIf="isKeyboardHidden">
<ion-row>
<ion-col class="ion-text-center">
<p class="light-gray">
{{'DEVELOPED_BY' | translate}}
<span class="bold">
<a class="default-text"
href="https://www.my-company.com/"
target="_blank">
My Company
</a>
</span>
</p>
</ion-col>
</ion-row>
</ion-footer>
Any ideas or pointers what I am (still) missing?

Answer 1

Here you can find official migration guide. They have listed all controls which they updated and Breaking changes:
https://github.com/ionic-team/ionic/blob/master/angular/BREAKING.md#breaking-changes