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

Two maps on the same page - Side-by-side

    How good I am feeling to post a code example after such a long time! It's been all "news" over the past so many posts! Well now that I am finally doing a code example, I am posting a very highly requested code sample. Placing two Google Maps on the same page (Now that's simple you would say!), but side by side. Now this is the thing that most people struggle with. Well, implementing the second part is also very simple, as you will see in today's code.     Let's see the code. Here it is!     The output of the above code will be as seen in the result section above.     As most of you will realize, there are two maps, one centered at "Pune" and other at "Noida". Why I chose these two locations? Well, just like that!...The main issue of concern is how the maps appeared side-by-side and not one below the other as would be normal behavior of two "div" elements used in the same page. Now here is the trick! Check out the...
10 comments
Read more

Four maps on the same page - Playing with events

    In today's example we will see how to add 4 maps on the same web page and then play a bit around with some events in Google Maps API. Lets have a look at the code. All that you have to do to get the code working is copy the code in a text file and save it with .html extension. Open this html file in your browser and you will see the four maps in action!     Adding the four maps on a webpage should not be a challenge anymore, and all the more after the example Two Google Maps - Side by side that I shared a few weeks back! All you need to pay attention is to the events. There are two events "drag" and "zoom_changed". As the event names suggest, when you will drag or zoom the first map (upper left map), the remaining three maps will also zoom and pan accordingly! Try it out and leave a comment of what you think of it! You can also drop your queries or doubts about the same here!     The output of the above code appears as seen in th...
4 comments
Read more

Reverse Geocoding

    The term geocoding generally refers to translating a human-readable address into a location on the map. The process of doing the converse, translating a location on the map into a human-readable address, is known as reverse geocoding. You can read more about geocoding here .     The Geocoder in Google Maps API v3, supports reverse geocoding directly. While geocoding, we supply a textual address and that gets mapped as a location on the map. However, in reverse geocoding, instead of supplying the textual address, we will supply a comma- separated latitude- longitude pair and get a textual address as the result. You can have a look at the geocoding example here , before proceeding to the reverse geocoding example.     The reverse geocoder often returns more than one result. Geocoding "addresses" are not just postal addresses, but any way to geographically name a location. For example, when geocoding a point in the city of Agra, India,...
Post a Comment
Read more

Overlays - A complex example

    In the last post we have seen what an overlay is and we have also seen a small simple overlay example as well. Today's example is a bit complex as compared to the last one, but is not at all difficult. We will directly jump to the code instead of having any more descriptions and stuff. So, here's the code.     The output of the above code looks as seen in the result section above. You need to click on the map to place a marker on the map. You can place multiple markers on the map by clicking on the map multiple times. By clicking on the "Clear overlays" button all the markers on the map will disappear. By clicking on the "Show all overlays" button, all the cleared, but not deleted markers will reappear. Clicking on the "Delete overlays" buttons will remove all the markers permanently.     If you have any doubts or queries regarding the code please leave a comment or drop me a mail .
1 comment
Read more