Skip to main content

CSS inheritance sequence

    Starting today, I will also write about a few things CSS apart from Google Maps Javascript API and Jquery Mobile. I will cover some really interesting things in CSS and keep updating this blog as and when I learn something new and think its worth sharing with you all.

    Today we will look at a very common mostly known thing in CSS - the inheritance sequence of CSS. Most of you reading this post must be aware that there are 3 ways in which you can include CSS into your web application.

  • External Stylesheet
  • Internal Stylesheet
  • Inline Styles

External Style Sheet
    An external style sheet is ideal when you are writing a style that would be applied across multiple pages. The external style sheet gives the developer lot of control over the look and feel of the entire website or web application. The external style sheet is included using the the "link" tag which is included in the head section.

<link rel="stylesheet" href="styles/default.css" />

Internal Style Sheet
    An internal style sheet is used usually when a single document has unique style. The internal styles are written as part of the "style" tag which is again included in the "head" section.

<style>
    p{
        font-size: 20px;
        color: #a123bb;
    }
</style>

Inline Style
    An inline style loses many of the advantages of style sheets by mixing the content with the presentation. Inline styles should generally be avoided and be used when absolutely necessary and unavoidable!

<p style="font-size: 20px; color: #a123bb;"></p>

    As we know and/or have learned from experience, that these styles cascade into one, let's say a "virtual" style sheet which gets applied on the entire web site/application. This cascade follows the following sequence to override each other and create one final style sheet. Number #4 in the following list has the highest priority in the cascade.
  1. Browser default styles
  2. External style sheet
  3. Internal style sheet
  4. Inline styles
    So an inline styles has the highest priority, meaning that it will override a style defined inside the "head" tag, or in an external style sheet or the default browser styles. However, there are a few cases where this sequence of cascade can change!

Case #1: Usage of the !important keyword
    In case there is the "!important" keyword associated with an of the styles, then that style would get applied irrespective of whether it is part of the internal or the external style sheet.

Case #2: Javascript
    When styles are applied through javascript, these styles will override all styles included as part of the internal or external style sheet or even the inline styles.

Case #3: Sequence of inclusion of stylesheets
    If the link to the external style sheet is placed after the internal style sheet in the "head" tag, the external style sheet will override the internal stye sheet!

    Hope you have enjoyed this post and learned a few new things. Do let me know in case you want me to include a topic as part of the blog and I would be happy to write about it! Till then keep reading and keep sharing.

Labels:

Comments

Post a Comment

Please leave your comments here...

Recommended for You

Retriving co-ordinates...

         We have seen 2 Google Maps API v3 examples wherein we have retrieved the latitude-longitude co-ordinates of the point of click on the map. In the first example we have displayed the co-ordinates in the information window and in the second , we have displayed the co-ordinates in a form in the information window.         Today we will create a code to retrieve the latitude longitude co-ordinates in a text box while simultaneously a marker appears on the map as well. So, here goes the code. <html> <head> <title> Google Maps API v3 - Adding marker on Click and retrieving the co-ordinates in a text box </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map;    //When using event as a parameter to a function declare map, strictly as a global variable fun...
5 comments
Read more

Google Street View Image API

    Street View is one of most used feature of the Google Maps and why not? You can actually see any part of the world as if you are visiting the place at that very moment. And now with the Google Street View Image API, you don't even need to carry a camera with you to the places you visit. You can take-in all the scenic beauty without even bothering about clicking a single picture. You can come back from your vacation and get a few images using the Google Street View Image API and show those images to your friends and relatives. Create an album of high definition images and go ahead and share it on Facebook for your friends to have a look.     Using the Google Street View Image API is very simple and anybody can make use of it without any programming knowledge required. I will walk you through the entire process of effectively using the Google Street View Image API. So if you are set, let's go on an amazing ride across the globe with the Google Street Views. ...
1 comment
Read more

Jquery Mobile - Listview with data-inset property

    In the previous post we looked at a basic example of the jQuery Mobile listview. The listview in jQuery Mobile stretches 100% of the width with sharp edges and straight corners. If you wish to have rounded corners for your lists you need to make use of the data-inset="true" property.     Lets take a look at the example below. The lists as seen in the result below have rounded corners as opposed to the straight edges in the example in the previous post, where we had not made use of the data-inset property. When we say that we did not use the data-inset property, we mean that the value of data-inset property is "false". UPDATE: The following example makes use of the next stable version of Jquery Mobile 1.3.1     Hope you have followed the post. Do let me know your feedback on the same and drop your commenets below.
Post a Comment
Read more

Jquery Mobile - Basic Listview

    Continuing with the Jquery Mobile Examples, today we will take a look at the listviews in Jquery Mobile. Listviews are popularly used in websites and web-applications that are built on the Jquery Mobile platform and hence we will look at the various list patterns available with Jquery Mobile. Lists are used for a various purposes like data display, navigation, result lists and data entry. We will start with the most basic listview example and look through several examples over a number of posts.     A listview is simply an unordered list containing linked list items with a data-role="listview" attribute. jQuery Mobile will apply all the necessary styles to transform the list into a mobile-friendly listview with right arrow indicator that fills the full width of the browser window. When you tap on the list item, the framework will trigger a click on the first link inside the list item, issue an Ajax request for the URL in the link, create the new pag...
Post a Comment
Read more

Jquery Mobile Form - Search input

    Input field of type search is newly introduced in HTML5 and is very well styled. The style is further enhanced when using the Jquery Mobile framework and we will see how this can be done in today's post. Jquery Mobile styles the search input type with capsule-corners and adds a 'x' icon to the right end, which clears the text in the search box.      The seacrch input elements are available in 2 flavors/sizes - regular and mini.   Adding a data attribute data-mini="true" to the input tag renders a smaller sized input element. Let's take a look at the code sample below to understand the working in a better way.      In the code above, you will see 4 different implementations of the input search element. The first one is a regular input of type search with the label and the searchbox one below the other. The second implementation is exactly similar to the first implementation with the only difference of the added data attrib...
Post a Comment
Read more