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

Playing with the markers and info window bubbles...

    In the last few posts, we have seen some marker examples and some information window examples. Now, lets do something interesting combining these two things. Just writing that "This is an info window" in the information bubble is not very interesting! And I know this...Have gone through the same phase!     So, today we will do something interesting! We will display the latitude- longitude co-ordinates of the point that the user clicks on the map! Doing this is not at all complex! Copy paste the following code and you will see for yourself a map coming to life!     The output of the above code looks as seen in the result section above! If you have any queries regarding the above code please comment on the blog post or feel free to contact me at my mail ID .
3 comments
Read more

Material UI, Google Polymer & Web Components

    Google introduced Material UI during the Google I/O a few days back. Since then the web is all abuzz with articles about material UI and what Polymer is and how these 2 fit together. In this article today, I will try and helps us all to get a better understanding of these new concepts.     So, let's start with Material UI first. Google has for long been trying to bridge the gap between the Web and the Android worlds with a unified user interface and Google's Material UI is a big step towards this. The new design philosophy is about dynamically adjusting the elements according to screen size, add more white space between elements, provide a lot of user feedback using animations, make use of bold UI colors and be flat and 3D about the design at the same time. Now that sounds really cool, isn't it? Well, actually it is and you will actually appreciate and enjoy it all the more when you watch the following video from this year's Google I/O.   ...
Post a Comment
Read more

Form info window

         Today we will look at a Google Maps API v3 example to add a form in the information bubble! This is usually required when we wish to accept some data/information from the user! This data can be saved to a server in the form of an XML file or a database! The information can then be retrieved back at a later stage, when necessary!          In this example we will only look at form in the information bubble! The connectivity part with the server will be discussed in another post! So, today's code snippet is as seen below! <html> <head> <title> Google Maps API v3 - Adding marker and info window on Click and creating a form in the infowindow with the lat-lng information in it. </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map;    //When using ev...
5 comments
Read more

Curious scenes in Google Map Satellite view...

            Most of you'll must have already seen many images like air crafts, brand logos, animals captured in the Google Satellite images or Google Earth for that matter. I am going to point out some that I found amazing... Italy's Big Pink Bunny - Google Map Link Australia's Blue Tree - Google Map Link  Nevada's Desert Crop Circle - Google Map Link  England's Dino Maze - Google Map Link Oregon's Firefox Crop Circle - Google Map Link              The above images are just a few of the many amazing Google Satellite images available on the web...Hope you enjoy them! Feel free to post links and images similar to these, here... Update - March 15, 2012:         I just came across the following freaky street view in Google Maps. I am sharing the image and the actual Google link here. You will need to enable t...
2 comments
Read more

Geodesic Polyline

    Today we will have a look at a very interesting polyline example - "The geodesic polyline". Now the first question that will pop is "What is geodesic?". Mathematically, geodesic means the shortest line between two points on a mathematically defined surface, as a straight line on a plain or an arc of a great circle or sphere.     The next question after reading the above definition is clearly, "Why do we need geodesic polylines?" and that would be followed up with "What is this Great Circle?". We will discuss this first, before we move on to the actual example today. The example is very very similar to the normal polyline example, with just a small change.     Having said so, I will now try to explain why we need a geodesic polyline? The shortest distance between two locations on the earth is rarely a straight line as the earth is roughly spherical in nature. So any two points on the earth, even if they are very close lie on a curve a...
5 comments
Read more