Aurora Directives

Aurora directive had the built-in directives for aurora project.

Install

npm i --save @ibyar/directives

yarn add @ibyar/directives

Supported Directive

Structure Directives

• *if
• *for is same as ( *forOf )
• *forIn
• *forAwait
• *switch and (*case, *default)

Attributes Directives

• *class
• *style

How to use Structure Directives:

<div *if="x > 50"> x: is {{x}} </div>

<div *if="x > 50; else otherTemplate"> x: is {{x}} </div>
<template #otherTemplate> X is more than 50</template>

<div *if="x > 50; then thenTemplate; else elseTemplate"> will be ignored </div>
<template #thenTemplate> x: is {{x}}</template>
<template #elseTemplate> X is less than 50</template>


<div class="col-3" *forOf="let user of people">
    <p>Name: <span>{{user.name}}</span></p>
    <p>Age: <span>{{user.age}}</span></p>
</div>
<div class="col-3" *for="let user of people">
    <p>Name: <span>{{user.name}}</span></p>
    <p>Age: <span>{{user.age}}</span></p>
</div>

<div class="col-3" *forOf let-user  [of]="people">
    <p>Name: <span>{{user.name}}</span></p>
    <p>Age: <span>{{user.age}}</span></p>
</div>

<div class="col-3" *forIn="let key in person1">
    <p>Key: <span>{{key}}</span></p>
    <p>Value: <span>{{person1[key]}}</span></p>
</div>

<div class="col-3" *forIn let-key [in]="person1">
    <p>Key: <span>{{key}}</span></p>
    <p>Value: <span>{{person1[key]}}</span></p>
</div>

<div class="col-3" *forAwait="let num of asyncIterable">
    <p>num = <span>{{num}}</span></p>
</div>

<div class="col-3" *forAwait let-num [of]="asyncIterable">
    <p>num = <span>{{num}}</span></p>
</div>

<div class="col-3" *switch="1">
    <div *case="1">One</div>
    <div *case="2">Two</div>
    <div *case="3">Three</div>
    <div *default>default: Zero</div>
</div>

How to use Attributes Directives:

<div class="row">
    <div [class]="$propertyFromModel"></div>
    <div class="col-{{width}}"></div>
    <div [class]="'col-6'"></div>
    <div [class]="['col-4', $textColor_fromModel, 'text-center']"></div>
</div>
...
<tr [class]="{'table-info': isEven, 'table-danger': isOdd}">
    ...
</tr>


<div [style]="'color: var(' + currentColor + ');'">...</div>
<div [style]="`color: var(${currentColor});`">...</div>
<div [style]="{color: 'var(' + currentColor + ')'}">...</div>
<div [style.color]="'var(' + currentColor + ')'"><div>

-- Directives now support input binding (one way/two way/ output=event)

Structural directive syntax reference

When you write your own structural directives, use the following syntax:

*:prefix="( :let | :expression ) (';' | ',')? ( :let | :as | :keyExp )*"

The following tables describe each portion of the structural directive grammar:

prefix	HTML attribute key
key	HTML attribute key
local	local variable name used in the template
export	value exported by the directive under a given name
expression	standard Aurora expression

keyExp = :key ":"? :expression ("as" :local)? ";"?
let = "let" :local "=" :export ";"?
as = :export "as" :local ";"?

How Aurora translates shorthand

Lke Angular translates structural directive shorthand into the normal binding syntax as follows:

Shorthand	Translation
key and naked expression	[key]="expression" Notice that the prefix is not added to the key
let	[export]="local"

Shorthand examples

The following table provides shorthand examples:

Shorthand	How Aurora interprets the syntax
*for="let item of [1,2,3]"	<template *for [item]="$implicit [of]="[1,2,3]">
*forOf="let item of [1,2,3] as items; trackBy: myTrack; index as i"	<ng-template *forOf [item]="$implicit" [of]="[1,2,3]" [items]="of" [ngForTrackBy]="myTrack" [i]="index">
*if="exp"	<ng-template [if]="exp">
*if="exp as value"	<ng-template [if]="exp" [value]="if">

-- in *for trackBy not supported yet.

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