I have a repeater of div's that look a little bit like this:
<div class="header_div">
<!-- Content -->
</div>
I want to have the background color of the divs change based on a dynamic property of the content of the div (lets call it the category), but I still want the "header_div" style to be assgined in cases where I dont have a css class for that category. Whats the best way of doing this?
The best way I can think of is to render the category as the "id" of the div and apply styles based on the id, but that strikes me as really messy - standards dictate that the id should uniquenly identify the element on the page and there will definitely be repeats of each category.
The simple answer would be to use multiple classes for the <div> so that
<div class="header_div header_red">
<!-- Content -->
</div>
<div class="header_div header_green">
<!-- Content -->
</div>
You're correct about the need for IDs to be unique.
There's nothing stopping you from specifying more than one value per class attribute - just separate them with a space.
<div class="header_div category">
<!-- Content -->
</div>
Just be careful to check what happens when both classes specify different values for the same style - I can't say whether the first or the second would take precedence.
You could supply multiple styles for the div class:
<div class="header_div mystyle">
<!-- Content -->
</div>
I believe styles declared later in the declaration override earlier ones. As long as you ensure your custom styles "shadow" those of the header-div, you can always include the header-div element, and it will only have an effect when any secondary style is absent (or empty).
If it's going to be used repeatedly on the page, it should be a class.
If it's unique on the page, use an id.
Without knowing more about your content, can you not use one of the header tags (<h1> etc)?
You are correct, IDs should be unique and if you want to use the same style more than once then use a class.
You can't have duplicate IDs so if you had multiple divs of the same category you would have an issue. Classes should be used when the style needs to be applied for 1 or more items on a single page.
Why not assign the class on databinding of the div based on the category? As your repeater is getting bound, find your div for the item you are binding and assign it.
You could also substitute the div for an asp:Panel and use it's onDataBinding method. It should look exactly like your div.
Related
I have to create a primary heading component, below is my markup along with CSS classes. I'm following BEM naming convention for class name.
I have h1 element consists of two spans. One span for main heading text, and second span for sub heading text. The main and sub are variations of my heading.
I have not specified the Element class (Which could be heading-primary__text ) and i have directly attached modifier classes to span elements.
<h1 class="heading-primary">
<span class="heading-primary--main">Video Background Option</span>
<span class="heading-primary--sub">One Page Parallax</span>
</h1>
Is that a right way to follow BEM methodology without specifying Elements classes & attaching Block's modifiers classes to Elements(span)? Because i don't need elements classes.
Is there any alternate?
While this is subjective, and as per the convinience of the project . i'd recommend doing something like this- as you already have a header-primary_text element class
<h1 class="heading-primary">
<span class="heading-primary_text">Video Background Option</span>
<!--create a modifier -->
<span class="heading-primary_text--sub">One Page Parallax</span>
</h1>
In this way you can make the sub a modifier class for the subtext.
More info can be seen here https://en.bem.info/methodology/quick-start/#modifier
Hope this helps :)
I think there is a much simpler way to do this just using basic HTML. You only want to have one h1 per page and since you said that your second span of your h1 is a "subheading" I feel like you would be way better off marking that one as an h2 instead of two spans of different context within one h1 heading! Always good to use the built in benefits of HTML first if you can.
No, it is not the right way. You cannot use block (or element) modifier alone on the HTML tag without specifying the block (or element) class itself.
Please refer to BEM documentation here: https://en.bem.info/methodology/quick-start/#modifier
A modifier can't be used alone From the BEM perspective, a modifier
can't be used in isolation from the modified block or element. A
modifier should change the appearance, behavior, or state of the
entity, not replace it.
Here is a code example from the docs:
<!-- Correct. The `search-form` block has the `theme` modifier with the value `islands` -->
<form class="search-form search-form_theme_islands">
<input class="search-form__input">
<button class="search-form__button">Search</button>
</form>
<!-- Incorrect. The modified class `search-form` is missing -->
<form class="search-form_theme_islands">
<input class="search-form__input">
<button class="search-form__button">Search</button>
</form>
You mentioned that you don't need an element class, this topic is also covered in BEM docs
https://en.bem.info/methodology/faq/#why-include-the-block-name-in-modifier-and-element-names
semuzaboi's suggestion sounds as a good alternative to me.
First of all, elements are specified after two __ like block__element_modifier.
Secondly, yes. Blocks may not have any elemenets inside, but rather have modifiers (most common case a block with lang modifiers for Internationalization (block_lang_ru))
PS as well as element may not have any modifiers inside. But block can not be nested inside another one. They should be placed inside one directory on the same level.
I understand from reading similar posts that the <section> tag in html is meant for semantic and organizational purposes. I was wondering, however, why using the <div> tag with a class attribute wouldn't have a similar effect.
(e.g. <div class = "SectionOne">)
Given these two methods, I could refer to each of them in CSS by using their respective names:
Section
{
color = white;
}
or
.SectionOne
{
color = white;
}
Personally, I think the second method allows for greater versatility in webpage design and I don't see many advantages to the new HTML5 feature. Would anyone care to clear this up for me?
section is usually used for having article like contents whereas div are meant to combine various block elements in order to style them differently. The main difference is just semantics.
Refer https://www.thoughtco.com/difference-between-div-and-section-3468001 for derails
Let me know if you require any further help
The <section> tag defines sections in a document, such as chapters, headers, footers, or any other sections of the document.
Whereas: The <div> tag defines a division or a section in an HTML document. The tag is used to group block-elements to format them with CSS.
Maybe you mean section and not Section. Anyway, the semantics is a thing and the selectors another. In CSS it is better to select using classes than tag selectors, because you gain a lot in terms of versatility. So you are right from this point of view. Semantics is another matter: is not given by a class. Even if you give a "section" class to a div, you are not giving semantic meaning to a div.
<div> is simply a generic block-level element which predates the later, semantically-named, document-related elements which arrived with HTML5, such as:
<header>
<nav>
<main>
<section>
<aside>
<footer>
When dividing up a document into its anatomical parts, you could still use:
<div class="header">
<div class="section">
etc.
But... you don't need to anymore.
Of course, even if you still use all of the above in your document you might still want to add other block-level elements and when you do... <div> is general purpose.
Normally CSS is my thing, but I'm somehow dumbfounded why this isn't working for me. I'm building a site through Cargo for CMS purposes and you can see it here: http://cargocollective.com/mikeballard
In my menu, I have five main categories, and clicking on them (images, for example) reveals the list of work under that category.
<div id="menu_2444167" class="link_link">
<a id="p2444167" name="mikeballard" target="" href="http://cargocollective.com/mikeballard/filter/images">Images</a>
</div>
<div id="menu_2444188" class="project_link">
<a name="mikeballard" rel="history" href="mikeballard/#2444188/Ultra-Nomadic-Def-Smith-Cycle-2011">Ultra Nomadic Def Smith Cycle, 2011</a>
</div>
<!-- more divs here -->
<div id="menu_2444201" class="project_link">
<a name="mikeballard" rel="history" href="mikeballard/#2444201/Archive">Archive</a>
</div>
Basically, I'm trying to select the last div in this set, and add a margin-bottom:15px to that div. I've tried using:
.project_link:last-child or .project_link:last-of-type but it doesn't seem to be working.
The HTML, which can't be altered too much to rely on Cargo, isn't great as if they had used list items, instead of divs with anchor tags I'm assuming this would be a lot easier.
The :last-of-type and :last-child selectors are not supported before IE9.
Class names, etc are not looked at when it comes to the :last-child and :last-of-type selectors. The .project_link:last-child selector will only trigger if the specific element is the last child in the parent element and has the class "project_link", and the .project_link:last-of-type selector will only trigger if the specific element is the last element of that type and has the class "project_link".
Both should trigger in a supporting browser, since it is implied as *.project_link:last-of-type and will check for every type of element inside that parent (which appears to only be divisions anyways). The last division shown here has the class "project_link" which would match this rule. The only reason these wouldn't trigger is if you had extra elements (or divisions) below what you're showing us, or you're using a browser which doesn't support it.
In using CSS is it best practice to use a div id only once per page. I know each id has to be unique but could be used multiple times. A discussion with my development team and it came up that one person was under the impression that you could only use the div id tag once per page.
Example of 1 id per page:
<page>
<div id="test">Some Text</div>
<div class="test12">More Text</div>
</page>
Example of multiple id's per page:
<page>
<div id="test">Some Text</div>
<div id="test12">More Text</div>
</page>
I hope that's clear enough. If not let me know and I can try to explain it better.
You can certainly use the id="" attribute as many times as you need, but the contents of the attribute should be unique. Not having a unique value is a HTML error.
If you need multiple items to have the same attribute, then you can set them as a class.
More info is at the W3C - Element identifiers: the id and class attributes (the HTML 4.01 Specification).
First, tags usually refer to elements such as div, a, img, body, ... Attributes are values given inside the tags such as id, class, href, ...
The id attribute can be specified once for each tag, with the constrain that no two tags share the same id value.
Both your examples are valid.
id should be unique
see HTML spec
It is physically possible to have duplicate id's per page, but the reason you only want to use one id per page with CSS is because of CSS selectors. Doing a CSS select by id is expected to only return a single DOM item.
ID's are Unique Assigments for ONE element on A page.
You can use the "ID=" attribute more than once. You will need to make sure that ID="hi" is only used once as it is supposed to be a unique identifier at the element level.
Link to Supporting Documentation:
http://www.w3schools.com/tags/tag_DIV.asp
You can have many elements with id(s) if that's what you're asking. Just view the source code of this page for instance and you'll see many id(s).
If it is related to the CSS only then we can also use Class instead of Id for DIV tag
This is NOT a question about how to create columns in css - so please dont give me any css for doing that. I've just excluded it here for readability.
I have created two columns in css and I want to place items in them based upon some css class. I think this is possible but I'm not sure how.
<DIV id="col1">
<!-- I want to display everything with 'women' here -->
</DIV>
<DIV id="col2">
<!-- I want to display everything with 'men' here -->
</DIV>
<!-- this content is dynamically generated in a loop (PHP/ASP.NET)-->
<DIV id="products">
<DIV class="women">
Women's product 1
</DIV>
<DIV class="men">
Men's product 1
</DIV>
<DIV class="men">
Men's product 2
</DIV>
</DIV>
Edit: Just to be sure I don't want to duplicate the product list into col1 and col2. i want to move them. I only want once visible copy of each item.
So I have two columns - or areas on the page - whatever - doesn't matter for this.
I want to use css to take everything under .products.women and put it in column 1.
I want to use css to take everything under .products.men and put it in column 2.
How can I do this. These kinds of things are about my limit to css, but I know theres some cleverness I can use.
Currently I'm rendering into the columns in two separate for loops. I want to get away from this for two reasons :
I dont want to maintain 2 identical for loops - nor move that logic elsewhere
I want to make an 'iphone' friendly version and i figure this will make that easier.
You can't do precisely what you're asking for with CSS. But you can do .women { float: left } .men { float: right}, which may be just about as good.
This is kind of a band-aid on your fundamental problem, though, which is failure to separate your presentation logic from your control logic. Instead of having two identical for loops in your presentation logic, you should have one for loop outside of it that builds two arrays, then your presentation logic should use each the way that would actually be beneficial to it.
CSS it's a language used to describe the presentation of the (existing) content. You are
asking for programaticaly DUPLICATE or COPY some of that content.
You can either use ASP/PHP whatever languaje of choice to generate multiple copies of that content, or use javascript to copy-move-change it.
Actually javascript seems to fit your scenario.
EDIT: you have a similar previous question here: using css to duplicate html elements
Interestingly (but, at this point, completely uselessly), this is not only possible in the current draft of the CSS3 Advanced Layout Module (aka Template Layout), but the spec contains an example showing how to do exactly that (last example in section 3.4). So if you can stand to wait a fifteen years or so...