I would need to one of my component (which is relatively deep nested) to render component which would cover whole webpage. The thing is that if I would put position:absolute in mentioned child component it will be relative to some of its ancestors but not to body. What would be a way for me to achieve expected result? Thanks for all suggestions.
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I am working on a document editor application using Angular 6. It has a paper element which looks like a paper of fixed size.
The user can add multiple child elements(Angular components) to this paper element.
When the user adds children that occupy more space than the parent could afford, the div needs to be added automatically to the next div and if any of the child Divs are deleted, then the overflowing div needs to be added back to the 1st paper.
Is there a way to achieve this?
I have made a simplified stackblitz here.
I think you can use https://angular.io/api/common/SlicePipe. You can show only max count of child elements on page. But i think you must calculate count of pages and display it by ngFor. Good luck!
I recently realized how useless the position: static Is , It doesn't offer you anything unless the relative also does.
In fact my question Is "why not just adding this line to our CSS file ?"
* { position:relative; }
so we are always able to easily position any element absolutely from It's parent or moving the element It self around just by left: ... or the same for any direction.
so why elements are not positioned to relative by default?
thanks
Let's take some element in its default static state and make it position: relative;. Just by changing that value alone, nothing happens. It appears in the exact same place that it did before the change. But it does change two things:
It's original location will still be occupied by the element (like there is a ghost of the original element still there taking up space).
If the element has child elements that are absolutely positioned, they are now absolutely positioned within the context of this element.
Advantages
If all elements started out with relative positioning, all two of the items above you'd have naturally. Your top/right/bottom/left values work as you would assume they do right out of the box. Z-index "just works" as well. The positioning context is always constrained to the next parent element, which makes logical sense.
Disadvantages
Most notably, always constraining the positioning context to the parent element is limiting. Let's say you want to position an element in the upper right of the page regardless of where the element appears in the markup. That's going to be tough if the element is buried down the hierarchy. You'll need to reset that positioning context for every parent element. That means setting them back to position: static;, and losing all the benefits of relative positioning along the way.
static positioning is the default because it simply doesn't "interfere" with the positioning of any other element on the page. In that sense, it is the least disruptive state an element can have.
Also, when we are talking about the rendering of the web page which is a very costly and sophisticated operation - it's faster to just draw a page with a lot of static elements than otherwise positioned elements. Modern browsers definitely are very advanced in that regard, but it certainly played a role for browsers 20 years ago.
In terms of convenience: Imagine an element on a dynamic page which you want to position absolutely. You know, which element you want to position it to, but you don't know how many levels might be in between.
With static positioning, you just declare position:relative on your anchor element. With all elements having relative positioning you somehow would need to reposition all elements in between, giving you a hard time.
Is it possible to set z-index that only applies to a certain 'scope', such as only affecting children of a certain element.
I've got an containerDiv with z-index 0. It contains a bunch of circles which should be placed on top of eachother in various depths, but I don't want them to affect any other elements on the page.
I've got a bunch of other elements on the page (popups, dropdowns etc) which have z-index 1, and I would like them to be placed on top of the containerDiv and all of it's childelements.
Since I'm lazy I'd preferably want to avoid having to adjust these element's z-index values based on the circle with the highest z-index...
Much be awesome if there was some way that all other elements could view the containerDiv and all it's children as having the same z-index.
Is this possible to achieve with css?
The answer depends on whether or not your other elements are descendants of the containerDiv or not. To answer the question: Yes, it's almost certainly possible, given a bit of shuffling of the markup.
But what you need to understand is the concept of stacking context:
http://www.w3.org/TR/CSS2/visuren.html#layers
Stacking context is not inherited the way other properties are: "A stacking context is atomic from the point of view of its parent stacking context; boxes in other stacking contexts may not come between any of its boxes." It's not like every element on the page with z-index:2 will be behind everything on the page with z-index:4. Z-index (combined with a position declaration) is typically (though not exclusively) used to resolve the stacking order when two elements share a containing element.
I sometimes find myself creating a div which serves no other purpose than to hold another element.
For example when creating a menu, I would create a div and assign it a background colour, position etc. Then within it I would create an unordered list.
I could surely assign all the properties I assigned to the DIV to the UL and not use a div at all.
Any ideas of what is best practice and reasons for it.
Thanks
Zenna
DIVs can be useful for grouping semantically related elements. If you are simply wrapping a single element that is also a block element, then you are simply adding bytes to the file.
No, they are not. The purpose of a div element is to create block level structure in the document. If you can lose them just lose them. Never use divs to solve design purposes, css is for that. Use html elements each like list, data definitions or tables (which were overabused in the past and used as the divs are now for css purposes). The more diverse your HTML knowledge is the less you are using divs all over the place.
I use often divs to keep child-padding/margins from ruining parent-width. But you need to be careful with this type of stuff - you could end up adding a bunch of nonsense.
The real issue is that we are using HTML in ways that its creators had never imagined. The need for 'all those divs' is because some really smart people have found some very creative ways to take a very old standard and do some very modern things with it.
Best practice should be to use as few div elements as possible. If you've got a div elements with only one child, chances are it's a useless div. The div element should really only be used when you need a block element and there is no semantic pre-defined element at hand. This includes grouping elements as Renesis suggests.
In the case of a UL, yes, the DIV is unnecessary. They are both block elements, so anything you can do with a DIV wrapped around the outside you can do directly to the UL itself.
However, because of the Box Model problem with some IE browsers, some people tell you to add these DIVs as a workaround. When you combine padding and width, IE6 disagrees with other browsers about what the final size of the element will be. So one workaround is to put padding but no width on an inner element, and width but no padding on an outer element.
Div's are really a necessary evil without a more semantically rich set of tags.
Their purpose is to server as a generic container. Therefore, I suppose you could say they do their job well.
If you can do what you're trying to do without the additional div, then leave it out. If it's an important part of your design that you can't fix with some clever CSS, then it's still a whole lot better than using tables...
I use DIVS primarily for at least one of two main reasons:
I need it to provide a new physical level of CSS in some way (either child padding inside a fixed width element, a shadow or a double border around an image, etc.)
It logically groups the elements it contains (for future portability and semantics in both HTML and CSS - I.E. "div#menu .label". This way I can use the "label" class several places but have a specific style applied to labels within the "menu" div).
For example, if you were to transfer all attributes to the UL, but then decided you wanted a caption or image above or below the menu but in the same location, you would have to create the DIV again to place the new element inside, and transfer half of the attributes back to it.
I'm working on an application with a map and there is a div in the corner with some stuff in it. You can click on this map to bring up some information in a little window. The window is, in some cases, being covered by the div in the corner.
I want the opposite effect (window covers div). I figured this would simply be a z-index issue but I'm unable to get it to work. This is with IE7 and from reading up a bit it seems like z-index won't work unless it's inside of an element that is positioned.
The elements seem to be positioned properly to get the z-index to work right but I'm having little luck. I've played around with adding styling via Firebug but haven't had any luck in getting anything to change. The window really is just two divs one absolutely positioned one and a relative one inside of it.
Is the z-index the only thing that could be the problem here or is there something else I don't know about?
Are there any other methods to achieve the effect I want? I cannot simply hide the div via jquery or something because part of it should be visible from behind the window that opens on the map.
You are hitting the stacking context bug
http://therealcrisp.xs4all.nl/meuk/IE-zindexbug.html
Every positioned div in IE will create a new stacking context and prevent z-index from diferent stacking contexts to come on top of others.
The solution is to have the window you want on top up in the tree (into the body for example) and z-index value grater than z-index of all parents of the other div covering your window.
Extensive information to understand the problem here:
http://richa.avasthi.name/blogs/tepumpkin/2008/01/11/ie7-lessons-learned/
positioning and negative margins is the only way to get elements to overlap that i know of. z-index is just used to explicitly tell the browser how to layer the elements.
as to your problem, IE requires the container elements and/or elements that you are overlapping to have position:relative; or position:absolute; for z-index to work properly. When someone say positioning they're usually implying having the position property set in CSS. Also when working with z-index make sure that the overlapping elementa are at the same level with each other.
Hope this helps
Quite simply, the order of the elements in your HTML file will determine stacking order. If you want an element to be above another then make sure it comes later in the HTML.
You can only swap the stacking order on elements that are all in the same containing element. For example if you have two divs and they both contain 3 images you cannot make images from the second div go below images from the first div.
You need to plan your HTML ahead if you need complex stacking orders.
As hinted by the other answers, position:relative and position:absolute reset the "stacking-context" in IE.
If you want a lazier answer you could use javascript and hide the div when you click on the map, and show it when you close the map.
You will have to do this with any selects on the page anyway because in ie they don't work with z-index.
I ran into this same issue a couple days ago and found the negative margin as suggested by Darko Z worked great. (My rep isn't good enough yet to vote for Darko)
I wrote a quick post on it.
http://www.swards.net/2009/03/layering-html-elements-without-using.html