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Difference between revisions of "Using Class Suffixes"

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===Page Class Suffix (With a Leading Space)===
 
===Page Class Suffix (With a Leading Space)===
Again in the back end, go back to Menus &rarr; Example Pages &rarr; Section Blog. We're going to change the value of the Page Class Suffix. This time we're going to enter in a leading space and call it <space> + "myBlogClass".
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Again in the back end, go back to Menus &rarr; Example Pages &rarr; Section Blog. We're going to change the value of the Page Class Suffix. This time we're going to enter in a leading space and call it <space> + "myBlogClass", as shown below.
 +
 
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[[Image:Page_class_suffix_space.png]]
  
 
Now, go back to the front end and re-display the Example Pages &rarr; Section Blog. Notice that our styling is back! Let's look at the HTML source to see what is going on. Open the source and find the first occurrence of "myBlogClass". It should like this: <pre><div class="componentheading myBlogClass">
 
Now, go back to the front end and re-display the Example Pages &rarr; Section Blog. Notice that our styling is back! Let's look at the HTML source to see what is going on. Open the source and find the first occurrence of "myBlogClass". It should like this: <pre><div class="componentheading myBlogClass">

Revision as of 13:14, 13 January 2009

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This tutorial will show you how to use Page, Module, and Menu Class Suffixes in Joomla! 1.5 to fine-tune the appearance of your site. For the tutorial, we will assume you have the Joomla! 1.5.9 Sample site available.

Contents

Background

Joomla! creates HTML pages that use Cascading Style Sheets to control the appearance of the page. This includes things like fonts, colors, margins, and background. The CSS files are part of your template.

When Joomla! creates a page, it creates different CSS classes that are then referenced in the CSS file to specify which style will apply to which parts of the HTML page. These class names are pre-programmed into Joomla!. But Joomla! allows you to modify or add CSS classes by way of the Class Suffix parameters. This lets you fine-tune the appearance of specific pages with no programming and very little work. The best way to understand this is to see specific examples.

When Would You Use a Class Suffix?

Say, for example, that your website contains a number of Section Blog layouts, each for a different Section. If you are happy to have all of these pages styled the same way, then you wouldn't need to use a Page Class Suffix. However, say you want each of these sections styled differently than the others. For example, maybe you want a different background color or image for each different section.

If you modify the styling for the standard CSS classes in the Section Layout, it will affect all of the Section Layout Menu Items in the same way. However, using a different Page Class Suffix on each Section Layout Menu Item will allow you to create different CSS classes for each individual Menu Item so you can style these differently.

Page Class Suffix

Before you start, make sure you have the Joomla! sample website available. Also, make sure the default template is set to "rhuk_milkyway" (in the Extensions → Template Manager).

How It Works Without a Page Class Suffix

Before we add a Page Class Suffix, let's see how this pages works without one. In the front end, navigate to Example Pages → Section Blog. In your browser, select the option to view the page source code. For example, in Firefox, press Ctrl+U. In Internet Explorer, select View → Source. In Safari, select View → View Source.

Using the "Find" command, find the first occurrence of the word "componentheading". It should look like the following:

<div class="componentheading">

Browse down the file and find the following tags:

<table class="blog" cellpadding="0" cellspacing="0"> 
<table class="contentpaneopen">
<td class="contentheading" width="100%">
<table class="contentpaneopen">

Note: The following screenshots were made using the free Firefox add-in called "Firebug". Firebug allows you to quickly see the relationship between the HTML elements in your source and the text and graphics shown on the page. It is a very handy tool, and you can get it here.

The screenshot below shows you the "componentheading" class. It is the page title area above the blog article.

Componentheading class firebug.png

This screenshot shows you the entire "blog" class. This is the outer table into which all of the articles will fit.

Blog class firebug.png

The next screenshot shows you the "contentpaneopen" class for an article heading. This includes the article title and the PDF, Print, and Email icons to the right.

Contentpaneopen class title firebug.png

This screenshot shows you the "contentpaneopen" class for the body of the article. This includes the author and date information as well as the actual article text.

Contentpaneopen class article firebug.png

So this gives us a good understanding of how Joomla! allows us to style the elements on a Section Blog layout. Joomla! writes out these classes as part of the HTML. And the template contains CSS that provides the styling information for these various elements and classes.

Page Class Suffix (No Space)

Now that we see how this works without a Page Class Suffix, let's try it with one. In the back end, navigate to Menus → Example Pages and click on "Section Blog". This should display the "Menu Item: [Edit]" screen for the Section Blog Layout. Click Parameters (System) to show the System Parameters. In the "Page Class Suffix" field enter the value "_myBlogSuffix" and click the Save button.

Now, go back to the front end and again navigate to Example Pages → Section Blog. Notice right away that we lost the styling for the page and article titles. Let's look closer to see why.

Using the browser "Find" command, find the first occurrence of "_myBlogSuffix". It is in a "div" tag and looks like this:

<div class="componentheading_myBlogSuffix">

If you look through the source, you should also see the following classes: blog_myBlogSuffix, contentpaneopen_myBlogSuffix, and contentheading_myBlogSuffix.

By adding the Page Class Suffix, we changed all of these class names. That means that special styling in the CSS file that refers to the "base" class names (like componentheading, blog, and so on) will not be applied, since those classes no longer exist on the page.

Now, you can fix this problem by editing your templates CSS file to add the same styling for the new classes (for example, "componentheading_myBlogSuffix"). But there is a much easier way to do this -- simply by adding a leading space to the parameter.

Page Class Suffix (With a Leading Space)

Again in the back end, go back to Menus → Example Pages → Section Blog. We're going to change the value of the Page Class Suffix. This time we're going to enter in a leading space and call it <space> + "myBlogClass", as shown below.

Page class suffix space.png

Now, go back to the front end and re-display the Example Pages → Section Blog. Notice that our styling is back! Let's look at the HTML source to see what is going on. Open the source and find the first occurrence of "myBlogClass". It should like this:

<div class="componentheading myBlogClass">

Because we put a leading space in the Page Class Suffix, we created a second class instead of changing the name of the first class (which is allowed and supported by all modern browsers). So we didn't break any of the existing CSS styling for this page. (One warning: we need to make sure the new class name is different than any of the other class names used on the page. Otherwise, we might get styling we don't want.)

Add CSS Styling to New Class

At this point, we've created a new CSS class in the HTML to allow for some new styling. Now we need to use this new class to actually change the look of our page. The first thing we need to do is find the applicable CSS file. In this case, it is <joomla_root>/templates/rhuk_milkyway/css/template.css.

Let's say we want to add a background color, but only to this specific Section Blog. (Remember, if we wanted to just change all of the Section Blog pages in our site, we could just change the CSS styling for the base classes, such as "componentheading" or "blog".) We need to do is figure out which area ("componentheading", "blog", or "contentpaneopen") we want to style. Say we just wanted to style the "componentheading" area.

First, let's use the CSS selector "div.myBlogClass" and add the following code to the end of our CSS file:

/* Custom Styling */
div.myBlogClass {
        background-color: #FFE4E1; /* mistyrose */      
}

The result is that the page heading now has the background color, as shown below.

Div styling example.png

Now this works fine in our example, because the other classes are defined for "table" tags and not "div" tags. But it is normally better to be more specific in our style selector by styling only those elements that have both the desired base class and the new class. For example, let's replace the code above with the following code:

/* Custom Styling */
.blog.myBlogClass {
        background-color: #FAFAD2; /* lightgoldenrod */ 
}

This specifies that the new style will only be applied to elements that have both the "blog" and the "myBlogClass" styles. This gives us the background color over the entire "blog" area, as shown below.

Blog styling example.png

The great thing about creating a new class (with the leading space trick) is that we don't need to copy all of the existing styling for the base classes. We can just focus on the new styling that we want.

Now in this example, we focused on the Section Blog layout. The class names for different components might be different, but the process will be the same. The table below shows some common Joomla! layouts and a list of class names that can have Page Class Suffixes added.

Layout CSS Class Names Used
Article Layout componentheading, contentpaneopen, contentheading, contentpagetitle
Category Blog, Frontpage Blog, Section Blog componentheading, contentpagetitle, blog, contentpaneopen, contentheading, readon, blog_more
Category List, Section List componentheading, contentpane, contentdescription
Contact Category componentheading, contentpane, contentdescription, sectiontablefooter, sectiontableheader, category
Contact Layout componentheading, contentpaneopen, contentheading

So, to sum up what we have learned about using the Page Class Suffix parameter:

  1. Use a leading space to create a new CSS class. This way you don't have to worry about re-doing or breaking existing CSS styles.
  2. Look in the HTML source code to find the locations of the base and new classes.
  3. If desired, use Firebug to see which HTML elements correspond to which areas on the page.
  4. Add custom styling to the end of the "template.css" file, specifying both the name of the desired base class and the custom class in the form .baseclass.customclass as in the example above.