Wordpress

Monday, 14 December 2015

Sunday, 13 December 2015

WordPress Errors and How to Fix Them

Thursday, 5 February 2015

Wordpress Lesson

source : http://codex.wordpress.org/WordPress_Lessons

WordPress for Beginners

Designing Your WordPress Site

Lessons for Theme Development

There is a comprehensive list of articles on Template Files and Template Tags in the Templates article.

Website Development

Categories:

Frequently asked wordpress Question

1) What is WordPress?
Word press is a best Open Source CMS which allows it to be used free of cost. You can use it on any kind of personal or commercial website without have to pay a single penny for it. It is built on PHP/MySQL (which is again Open Source) and licensed under GPL.
2) How safe is website on WordPress?
The word press is safe to operate but still it is suggested to keep updating with the latest version of WordPress to avoid hacking.
3) Are there any limitations to a WordPress web site?
You can use WordPress for e-commerce sites, membership sites, photo galleries and any other type of site you can think of. The web site is created using the same html code as any other site so there are no limitations there either.
4) Do you need to have a blog in order to use WordPress for site?
WordPress was originally used as blogging software though it has since become popular for website also. It is not necessary to have a blog to use wordpress. Still having blog is commendable as it will help in search engine optimization.
5) From SEO point of view is wordpress helpful? Will it show the website on Google?
It is one of the benefit of using wordpress, it has inbuilt SEO search engine. Also, you can have an additional plug-in in wordpress to help with SEO and rank on a popular search engine like Google.

6) What is the current version of wordpress?
You need to quote the current version of WordPress available in market along with the release date.
7) What are the types of hooks in WordPress and mention their functions?
There are two types of hooks 1) Action hooks 2) Filter hooks
Hooks allow user to create WordPress theme or plugin with shortcode without changing the original files. Action hooks allow you to insert an additional code from an outside resource, whereas, Filter hooks will only allow you to add a content or text at the end of the post.
8) What do you mean by custom field in wordpress?
Custom field is a meta-data that allows you to store arbitrary information to the wordpress post. Through custom field extra information can be added to the post.
9) What are the positive aspects of wordpress?
Few positive aspects of wordpress are

Easy installation and upgrade
In-built SEO engine
Easy theme system
Flexibility
Multilingual- available in more than 70 languages
Own data- no unwanted advert on your website
Flexibility and Easy publishing option

10) What are the rules that you have to follow for wordpress plugin development?

Create a unique name
Create the plugin’s folder
Create a sub-folder for PHP files, translations and assets
Create the main plug-in file and fill in header information
Create activation and de-activation functions
Create an uninstall script
Create a readme.txt file
To detect paths to plugin file use proper constants and functions

11) What is the prefix of wordpress tables by default?
By default, wp_ is the prefix for wordpress.
12) Why does WordPress use MySQL?
MySQL is widely available database server and is extremely fast. It is an open source and it is available at no cost also it is supported by many low-cost Linux hosts so its easy for anyone to host their website.
13) Is it possible to rename the WordPress folder?
Yes, it is possible to rename the WordPress folder. If WordPress is already installed you have to login to the weblog as the administrator and then change the settings
WordPress address (URI) :
Blog address( URI) :
After making the changes, you can rename the folder or directory with the WordPress file in it.
14) How many tables are there in WordPress by default?
There are about 11 tables in WordPress by default. Note: With succeeding releases of WordPress this number will change. You need to check phpMyAdmin to determine the number of tables in a vanilla version of latest WordPress installation.
15) What is WordPress loop?
To display post WordPress use PHP code, this code is known as loop.
16) How you can disable the WordPress comment?
If you go on dashboard under options-discussion there is a comment “ Allow people to post comment” try unchecking the comment.
17) What are the steps you can take if your WordPress file is hacked?

Install security plug-ins like WP security
Re-install the latest version of WordPress
Change password and user-ids for all your users
Check your themes and plug-ins are up to date

18) What are the template tags in WordPress?
In WordPress template tags is a code that instructs WordPress to “do” or “get” something.
19) Does WordPress have cookies?
Yes, WordPress have cookies and WordPress uses cookies for verification of users while logged in.
20) In what case you don’t see plugin menu?
You can’t see your plugin menu when the blog is hosted on free wordpress.com as you cannot add plugin there. Also, if you do not have an account of an administrator level on your WordPress is not possible to see plugin.
21) At what instance you get locked out of your WordPress admin and see your website as a blank screen?
This would likely happen when you have pasted a code from a website with wrong formats, also when you have pasted a code in a wrong location. It may also happen when your IP is banned
22) Why you use a static front page in wordpress?
Some WordPress users wants their WordPress installation to be more than a blog site. To give their page a look more like a real website page some users use static front page.
23) What are the plugins you can use to create contact form in WordPress?
To create a contact form in WordPress you can use plugin like Gravity forms or also you can use a free plugin contact form 7.
24) Why widget does not show up in the sidebar?
While using widget you have to ensure whether your theme supports the widget and if it does then it must show the sidebar. If in any case if it happens that you don’t see the sidebar then it might be missing the “function.php” file or file similar to that. This can also happen if you have forgot to save the changes in the widget or refreshing the older display of the page.
25) Is there any limitation for using WordPress?
No, there is no limitation for using WordPress. WordPress can be used for innumerable purpose membership site, e-commerce site, photo-gallery and many more.
26) How is creating a site on wordpress.org different from wordpress.com?
Most of the things are similar in both except the choices of themes and the usage of plugins.
27) Why wordpress.com is considered more secure than wordpress.org?
WordPress.com is considered more secure than wordpress.org because they limit the themes and also does not allow installing plugin’s. However the security is more dependable on how the hosting company is hosting your website(wordpress.org) & also what are the steps they are taking to prevent the security problems.
28) Does de-activated plugins slow down a WordPress site?
No, de-activated plugins cannot slow down the WordPress site. Wordpress only loads the active plugins and ignores everything else.
29) In what case we cannot recommend WordPress to our client?
We cannot recommend WordPress on following situation:

If client is working on non-CMS base project
If site wants complex or innovative e-commerce
In case of enterprise intranet solution
Sites requiring custom scripting solutions.

30) What are the essential features you look for a theme?
Theme selection differs according to the requirement, but an ideal theme would be something that would not restrict to use the number of pages, plugins or static homepage.
31) How Custom theme is different than Normal theme?
Custom theme allows for SEO search, but with a SEO plugin available it would not make much difference to normal theme. One benefit using the Custom theme is that it allows to make the changes without going much into the coding part.
32) How you can create a static page with WordPress?
To create a static page in wordpress, in the page section you have to upload a php files to the server in the theme folder, and then select that as your template. This allows you to add any page and look that you wanted for your blog and it will remain static.
33) Is there any other CMS better WordPress?
WordPress is no doubt a good CMS, but Drupal and Joomla are among the best CMS you can work with.
34) Which is the best multi-lingual plugin for wordpress?
Keeping all the limitations in mind, WPML would be the best multi-lingual plugin for wordpress .
35) Can you update your own content on the site?
It depends on the type of the site or project, but yes one can update their own content on the site.
36) What are meta-tags?
Meta-tags are keywords and description used to display website or page information.
37) What should one use for plugin development — custom post types or custom database tables?
There is no specific preference for plugin development; it depends on what type of plugin’s one has to develop. Though few recommend custom post type, as it has few benefits comparison to custom database table.
38) Can you host WordPress using Amazon web services such as EC2, RDS, EBS etc?
Yes, you can host using Amazon web services.
39) Is there any way to write series in WordPress?
You can use organize series plugin to write series in wordpress.
40) What are the reasons why one should not hack WordPress core file?
The best reason not to hack the core files is that whatever you might be doing has to be reworked as a patch.

Sunday, 1 February 2015

Types of Post in Wordpress

Source : http://codex.wordpress.org/Post_Types

WordPress can hold and display many different types of content. A single item of such a content is generally called a post, although post is also a specific post type. Internally, all the post types are stored in the same place, in the wp_posts database table, but are differentiated by a column called post_type.
WordPress 3.0 gives you the capability to add your own custom post types and to use them in different ways.

Default Post Types

There are five post types that are readily available to users or internally used by the WordPress installation by default :

Post (Post Type: 'post')
Page (Post Type: 'page')
Attachment (Post Type: 'attachment')
Revision (Post Type: 'revision')
Navigation menu (Post Type: 'nav_menu_item')

Post

Post in WordPress is a post type that is typical for and most used by blogs. Posts are normally displayed in a blog in reverse sequential order by time (newest posts first). Posts are also used for creating the feeds.

Page

Page in WordPress is like post, but it lives outside the normal time-based listings of posts. Pages can use different page templates to display them. Pages can also be organized in a hierarchical structure, with pages being parents to other pages, but they normally cannot be assigned categories and tags. If permalinks are enabled, the permalink of a page is always composed solely of the main site URL and the user-friendly and URL-valid names (also referred to as slug) of the page and its parents if they exist. See the Pages article for more information about the differences.

Attachment

Attachment is a special post that holds information about a file uploaded through the WordPress media upload system, such as its description and name. For images, this is also linked to metadata information, stored in the wp_postmeta table, about the size of the images, the thumbnails generated from the images, the location of the image files, the HTML alt text, and even information obtained from EXIF data embedded in the images.

Revision

Revision is used to hold a draft post as well as any past revisions of a published post. Revisions are basically identical to the published post which they belong to, but have that post set as their parent using the post_parent column of the wp_posts table.

Custom Post Types

Custom post types are new post types you can create. A custom post type can be added to WordPress via the register_post_type() function. This function allows you to define a new post type by its labels, supported features, availability and other specifics.
Note that you must call register_post_type() before the admin_menu and after the after_setup_theme action hooks. A good hook to use is the init hook.
Here's a basic example of adding a custom post type:

add_action( 'init', 'create_post_type' );
function create_post_type() {
  register_post_type( 'acme_product',
    array(
      'labels' => array(
        'name' => __( 'Products' ),
        'singular_name' => __( 'Product' )
      ),
      'public' => true,
      'has_archive' => true,
    )
  );
}

This creates a post type named Product identified as acme_product. The register_post_type() function receives two major arguments. The first one is labels which define the name of the post type in both plural and singular forms. The second one is public which is a predefined flag to show the post type on the administration screens and to make it show up in the site content itself, if it's queried for.
There are many more arguments you can pass to the register_post_type() function, to do things like set up hierarchy (to behave like pages), show the new post type in searches, change the URLs of the new posts, and hide or show meta boxes in the post edit screen. These parameters are optional, and you can use them to configure your post type on a detailed level.

A word about custom post types as a plugin

In order to avoid breaking a site on theme switching, try to define custom post types as a plugin, or, better as a Must Use Plugins. This way you won't force users into using a certain theme.

Naming Best Practices

While it is convenient to use a simple custom post type identifier like product which is consistent with the identifiers of the default post types (post, page, revision, attachment and nav_menu_item), it is better if you prefix your identifier with a short namespace that identifies your plugin, theme or website that implements the custom post type.
For example:

acme_product or aw_product for products post type used by a hypothetical ACMEWidgets.com website.
eightfold_product or eft_product for products post type provided by a hypothetical EightFold theme.
ai1m_product for products post type provided by a hypothetical All-in-One Merchant plugin.

Without namespacing your custom post type identifier, other post types in your website will more likely conflict with custom post types defined in a theme you fall in love with later or a plugin you realize that you absolutely need to use. Or if you are developing custom post types or themes there is a much greater chance your plugin or theme will conflict with custom post types defined in other plugins or themes and/or custom post types defined in your prospective user's website. Namespacing your custom post type identifier will not guarantee against conflicts but will certainly minimize their likelihood.
Do pay close attention to not having your custom post type identifier exceed 20 characters though, as the post_type column in the database is currently a VARCHAR field of that length.

Reserved Post Type Identifiers

Although the core development team has yet to make a final decision on this, it has been proposed on the wp-hackers mailing list that future core post type identifiers will be namespaced with wp_, i.e. if the core team decides to add an event post type then according to this suggestion they would use the wp_event identifier. Even though this has not been finalized, it will be a good idea to avoid any custom post types whose identifier begins with wp_.

Custom Post Type Screens

When a custom post type is created like in the example above, it gets a new top-level administration menu to create and manage posts of that new post type. New administration screens will be accessible from that menu, such as post edit screen where you will have a full post editor and everything that comes along with it according to what features you set that your custom post type should support by the supports argument of the register_post_type() function. You can customize the screens with several action and filter hooks, see this Custom Post Type Snippets post by Yoast for an explanation and code examples on how to change a custom post type overview screen.

URLs

A custom post type will also get its own slug within the site URL structure. In the above example, a post of this product custom post type can be displayed at http://example.com/acme_product/%product_name% where acme_product is the slug of your custom post type and %product_name% is the slug of your particular product, so a permalink could be e.g. http://example.com/product/foobrozinator. You can see this permalink appear on the edit post screen for your custom post type, just like with default post types.

URLs of Namespaced Custom Post Types Identifiers

When you namespace a custom post type identifier and still want to use a clean URL structure, you need to set the rewrite argument of the register_post_type() function. For example, assuming the ACME Widgets example from above:

add_action( 'init', 'create_posttype' );
function create_posttype() {
  register_post_type( 'acme_product',
    array(
      'labels' => array(
        'name' => __( 'Products' ),
        'singular_name' => __( 'Product' )
      ),
      'public' => true,
      'has_archive' => true,
      'rewrite' => array('slug' => 'products'),
    )
  );
}

The above will result in post URLs in the form http://example.com/products/%product_name%. Note that we used a plural word for the slug here which is a form that some people prefer because it implies a more logical URL for a page that embeds a list of products, i.e. http://example.com/products/.
Also note that using a generic slug like products here can potentially conflict with other plugins or themes that use the same slug, but most people would dislike longer and more obscure URLs like http://example.com/acme_products/foobrozinator and resolving the URL conflict between two plugins is easier simply because the URL structure is not stored persistently in each post's database record the same way custom post type identifiers are stored.

Custom Post Type Templates

The WordPress theme system supports custom templates for custom post types too. A custom template for a single display of posts belonging to a custom post type is supported since WordPress Version 3.0 and the support for a custom template for an archive display was added in Version 3.1.
Note: In some cases, the permalink structure must be updated in order for the new template files to be accessed when viewing posts of a custom post type. To do this, go to Administration Panels > Settings > Permalinks, change the permalink structure to a different structure, save the changes, and change it back to the desired structure.

Template Files

In the same way single posts and their archives can be displayed using the single.php and archive.php template files, respectively,

single posts of a custom post type will use single-{post_type}.php
and their archives will use archive-{post_type}.php
and if you don't have this post type archive page you can pass BLOG_URL?post_type={post_type}

where {post_type} is the $post_type argument of the register_post_type() function.
So for the above example, you could create single-acme_product.php and archive-acme_product.php template files for single product posts and their archives.
Alternatively, you can use the is_post_type_archive() function in any template file to check if the query shows an archive page of a given post types(s), and the post_type_archive_title() to display the post type title.

Querying by Post Type

In any template file of the WordPress theme system, you can also create new queries to display posts from a specific post type. This is done via the post_type argument of the WP_Query object.
Example:

$args = array( 'post_type' => 'product', 'posts_per_page' => 10 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
  the_title();
  echo '<div class="entry-content">';
  the_content();
  echo '</div>';
endwhile;

This simply loops through the latest 10 product posts and displays the title and content of them one by one.

Custom Post Types in the Main Query

Registering a custom post type does not mean it gets added to the main query automatically.
If you want your custom post type posts to show up on standard archives or include them on your home page mixed up with other post types, use the pre_get_posts action hook.

// Show posts of 'post', 'page' and 'movie' post types on home page
add_action( 'pre_get_posts', 'add_my_post_types_to_query' );

function add_my_post_types_to_query( $query ) {
  if ( is_home() && $query->is_main_query() )
    $query->set( 'post_type', array( 'post', 'page', 'movie' ) );
  return $query;
}

Navigation menus code in wordpress

source : http://codex.wordpress.org/Navigation_Menus

Navigation Menus

Navigation Menu is a theme feature introduced with Version 3.0. WordPress includes an easy to use mechanism for introducing customised navigation menus into a theme. In order to incorporate menu support into your theme, you need to add a few code segments to your theme files.

Function Reference

Register Navigation Menu
`register_nav_menus()` `register_nav_menu()` `unregister_nav_menu()`

Show Navigation Menu
`has_nav_menu()` `wp_nav_menu()`

Register Menus

Firstly, in your theme's functions.php, you need to write a function to register the names of your menus. (This is how they will appear in the Appearance -> Menus admin screen.) As an example, this menu would appear in the "Theme Locations" box as "Header Menu".

function register_my_menu() {
  register_nav_menu('header-menu',__( 'Header Menu' ));
}
add_action( 'init', 'register_my_menu' );

And this would make two menu options appear, header menu and extra menu -

function register_my_menus() {
  register_nav_menus(
    array(
      'header-menu' => __( 'Header Menu' ),
      'extra-menu' => __( 'Extra Menu' )
    )
  );
}
add_action( 'init', 'register_my_menus' );

Display Menus on Theme

Once you've done that, your theme will be almost ready. The last preparation step is to tell the theme where you want the menus to show up. You do this in the relevant theme file. So, for example, we might want our header menu to be in header.php. So open up that file in the theme editor, and decide where you want to put your menu. The code to use here is wp_nav_menu which we will need once for each menu location. So, add this code -

<?php wp_nav_menu( array( 'theme_location' => 'header-menu' ) ); ?>

All you need to ensure is that the theme_location points to the name you provided for your menu in the functions.php code above. (Note that it's the header-menu being used here rather than Header Menu without a hyphen. header-menu is the name that the code understands, Header Menu is the human-readable version that you see in the admin page.)
To complete the code, you can put your extra menu someplace else. Maybe you want a menu on one of your pages, for example, and you might even want it to be jazzed up a little with a containing DIV of a certain class -

wp_nav_menu( array( 'theme_location' => 'extra-menu', 'container_class' => 'my_extra_menu_class' ) );

So you'd put the above into your Page template, and not only would the menu show up wherever you put it, it'd be styled as my_extra_menu_class so that you can work with that in CSS.

Menus Panel

That's all the background work. To finish, you would simply visit the Appearance -> Menus panel in your site admin. Now, instead of seeing some text suggesting that your theme doesn't natively support menus, you'll see some Theme Location options.
You can now use the GUI menu creator on this admin panel to put your menu(s) together. Give them each a name, and then assign a menu to a location with the pull-down options.
(You will see your new navigation choices when you Add a New Menu.)

Search Shortcode code in wordpress

Source : http://codex.wordpress.org/Function_Reference/get_search_form

Description

Display search form using searchform.php Theme file.

Usage


<?php get_search_form( $echo ); ?>

Parameters

$echo

(boolean) (optional) true to echo the form; false to return the form as a string.

Default: true

Return Values

(string): The form's HTML, if the $echo parameter is set to false.

Examples

Default HTML4 Form

If you don't have searchform.php in your Theme, WordPress will render its built-in search form:

<form role="search" method="get" id="searchform" class="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>">
 <div>
  <label class="screen-reader-text" for="s"><?php _x( 'Search for:', 'label' ); ?></label>
  <input type="text" value="<?php echo get_search_query(); ?>" name="s" id="s" />
  <input type="submit" id="searchsubmit" value="<?php echo esc_attr_x( 'Search', 'submit button' ); ?>" />
 </div>
</form>

The above form is used on HTML4 websites.

Default HTML5 Form

Since WordPress 3.6, If your theme supports HTML5, which happens if it uses:

add_theme_support( 'html5', array( 'search-form' ) );

WordPress will render its built-in HTML5 search form:

<form role="search" method="get" class="search-form" action="<?php echo home_url( '/' ); ?>">
 <label>
  <span class="screen-reader-text"><?php echo _x( 'Search for:', 'label' ) ?></span>
  <input type="search" class="search-field" placeholder="<?php echo esc_attr_x( 'Search …', 'placeholder' ) ?>" value="<?php echo get_search_query() ?>" name="s" title="<?php echo esc_attr_x( 'Search for:', 'label' ) ?>" />
 </label>
 <input type="submit" class="search-submit" value="<?php echo esc_attr_x( 'Search', 'submit button' ) ?>" />
</form>

Among the changes is that the form has a class="search-form". Also, the input is type="search" and not type="text". Furthermore there is a placeholder, which displays text when appropriate, which means you don't need javascript to display the placeholder. There are no elements with an id anymore, so you can have multiple searchforms in a valid document.

Theme Form

If you do have searchform.php in your Theme, it will be used instead. Keep in mind that the search form should do a GET to the homepage of your blog. The input text field should be named s and you should always include a label like in the examples above.
Example of a custom searchform.php:

<form action="/" method="get">
 <fieldset>
  <label for="search">Search in <?php echo home_url( '/' ); ?></label>
  <input type="text" name="s" id="search" value="<?php the_search_query(); ?>" />
  <input type="image" alt="Search" src="<?php bloginfo( 'template_url' ); ?>/images/search.png" />
 </fieldset>
</form>

The only parameter here that will be submitted is s with the value of the current search query. However, you can refine it in many ways. For example by only showing posts in the search results. This can be done with the next addition to the form above:

<input type="hidden" value="post" name="post_type" id="post_type" />

Here we submit the value post. The default value is any, meaning, posts, pages and custom post types. With the input above added to the form it will now only search in posts with the post_type post. There are many additions like this. With a var_dump of the object $wp_query you can see all the default values of the search variables. With a var_dump of $wp_query->query you can see the current query.

A last option is to write a custom function (in your functions.php file) and hook that function to the get_search_form action hook.

function my_search_form( $form ) {
 $form = '<form role="search" method="get" id="searchform" class="searchform" action="' . home_url( '/' ) . '" >
 <div><label class="screen-reader-text" for="s">' . __( 'Search for:' ) . '</label>
 <input type="text" value="' . get_search_query() . '" name="s" id="s" />
 <input type="submit" id="searchsubmit" value="'. esc_attr__( 'Search' ) .'" />
 </div>
 </form>';

 return $form;
}

add_filter( 'get_search_form', 'my_search_form' );

Notes

Please use value="<?php echo get_search_query(); ?>" (so a wrapper function for: esc_attr( $s ); and other necessary filters) if you'd like to display currently searched term in the search field once searching have already occurred. This is one of the most XSS vulnerable places in themes if not secured.