So it’s better to add or remove elements to the component element to the HTML DOM rather than hiding or showing them.īut as I said earlier if the component is simple it is better to hide or show it, because component reinitialization operation could be expensive. Memory burden might be high which results in poor performance, responsiveness can degrade and the user has no knowledge, why the application is slow. If both are used to hide or show elements then what is the difference between the two To understand that, see the figure below where I have used three div elements. This means that any other elements that would normally be positioned after it will still be positioned as if the hidden element. The content-visibility property accepts one of three values: hidden: The element bypasses its contents (kind of similar to applying display: none to the contents). If set to hidden, the element will be hidden from view, but it will still occupy space on the page. The component and its children components will be tie up resources. CSS display and visibility properties The display and visibility properties are used to show or hide HTML elements in web pages. The visibility property in CSS determines whether or not an element is visible on the web page. The component behavior still exists even though it is hidden. Clear understanding you must know the difference between display and Display property and visibility property both can visible and block the content, but the difference is Visibility property hidden the content. Visibility property used to make visible or hidden content or image from the page. ![]() In practice I tend to use display more than visibility. ![]() You want to use display when you want the element to give back its space allowing the other elements on your page to collapse around it. This means that any other elements that would normally be positioned after it will be repositioned as if the hidden element were not present. Visibility means something appearing or able to see. You want to use visibility when you want the element to hold its space even when it’s not seen. If set to none, the element will be completely removed from the page and will not occupy any space. Visibility: hidden hides the tag, but it still takes up space and affects the page. ![]() Angular keep on checking for changes related to data bindings. The display property in CSS determines how an element is displayed on the web page. And even though the component is hidden, the component will be attached to its DOM element. Hiding and showing the element after rendering is fine if the paragraph or div element is very small and with simple interaction.īut with Angular, we can build rich applications some of the components may use too many resources. Why ngIf directive remove the element rather than hide it? Irrespective of display hide or show the paragraph element will be added to the DOM. In fact, the HTML element affects the DOM. But the critical thing to keep in mind is: this HTML element still has an effect on the DOM. When visibility:hidden is applied to an HTML element, it is not visible in the page, which makes sense. This paragraph is hidden but still in the DOM.Īnd the generated HTML is ngIf hidden in Angular The difference between visibility:hidden and display:none in CSS is how the hidden element affects the DOM. Now we will see an example with hidden attribute in html5 and display none CSS. visibility: hidden makes the element invisible, keeps it in the document, but you can't click on it. When the element is set to hidden, the content of that tag becomes fully transparent, but it will display the place of it. The HTML might look like this: .opacity: 0 makes the element transparent, but keeps it in the document flow, and you can click on it. Angular will convert to a comment which gives us information about evaluated ngIf condition true or false. display: none takes it out of the document flow, and removes it from accessibility tree. ngIf vs HiddenĪnd the second div is not at all added the DOM. Have a look at a simple ngIf example This will be added to DOM by ngIfĪs explained in ngIf else article angular will convert the ngIf element to element.
0 Comments
Leave a Reply. |