-
Notifications
You must be signed in to change notification settings - Fork 772
Performance Considerations
@angular/flex-layout performs extremely well for most usage scenarios EXCEPT large tables.
Developers generating dynamic tables (using *ngFor
) should be aware of performance impacts using Flex-Layout
directives.
For small number of rows (e.g. < 100), @angular/flex-layout is a excellent choice for layouts. Consider the table
definition below were each row has column elements; each using a fxFlex
. Since the directives apply styles inline for
each element in each row, large tables may manifest performance impacts with dynamic inline stylings.
<div *ngFor="let obj of data" fxLayout fxLayout.xs="column">
<div fxFlex="40">{{obj.origin}}</div>
<div fxFlex="40">{{obj.destination}}</div>
<div fxFlex="20">{{obj.price}}</div>
</div>
Note that both the initial and media-query-triggered layout phase manifest redraw-performance issues.
Dynamic-inline-styling performance impacts are especially noticeable for column layouts.
Developers should note that FlexBox CSS with flex-direction = "column"
requires significantly more webkit engine
processing to properly adjust column heights and layout the composition. Reduce the demo viewport size to < 600px
(to force a column direction layout).
For responsive table layouts with large number of rows, developers should use the responsive class
API to specify
a flexbox CSS style class instead of inline flexbox styles.
Below we are using the responsive class
and class.xs
API to specify class names. Notice that mobile devices will
use a flow-direction == "column":
<div *ngFor="let obj of data" class="flow row" class.xs="flow column">
<div class="item_40"> {{obj.origin}} </div>
<div class="item_40"> {{obj.destination}} </div>
<div class="item_20"> {{obj.price}} </div>
</div>
.flow {
display: flex;
box-sizing: border-box;
-webkit-box-direction: normal;
.row {
flex-direction: row;
-webkit-box-orient: horizontal;
}
.column {
flex-direction: column;
-webkit-box-orient: vertical;
height:100px; /* important for sizing of row heights */
margin-bottom: 20px;
}
}
.item_40, .item_20 {
flex: 1 1 100%;
box-sizing: border-box;
-webkit-box-flex: 1;
}
.row .item_40 { max-width: 40%; }
.row .item_20 { max-width: 20%; }
.column .item_40 { max-height: 40%; }
.column .item_20 { max-height: 20%; }
This class
-based approach performs very well by leveraging stylesheets instead of inline-styles. Here is an
online StackBlitz - Flex-Layout Performance that
demonstrates the issue (see Use fxLayout
button) and solution (see Use CSS
button).
-
Quick Links
-
Documentation
-
Demos
-
StackBlitz Templates
-
Learning FlexBox
-
History
-
Developer Guides
-
Contributing