Displaying Data

Theming

Theming is a way to replace a set of views with another without the need of touching the original view rendering code. You can use theming to systematically change the look and feel of an application.

To use theming, you should configure the [[yii\base\View::theme|theme]] property of the view application component. The property configures a [[yii\base\Theme]] object which governs how view files are being replaced. You should mainly specify the following properties of [[yii\base\Theme]]:

Working with Client Scripts

Modern web applications, additionally to static HTML pages that are rendered and sent to the browser, contain JavaScript that is used to modify the page in the browser by manipulating existing elements or loading new content via AJAX. This section describes methods provided by Yii for adding JavaScript and CSS to a website as well as dynamically adjusting these.

Data widgets

Yii provides a set of widgets that can be used to display data. While the DetailView widget can be used to display data for a single record, ListView and GridView can be used to display a list or table of data records providing features like pagination, sorting and filtering.

Sorting

When displaying multiple rows of data, it is often needed that the data be sorted according to some columns specified by end users. Yii uses a [[yii\data\Sort]] object to represent the information about a sorting schema. In particular,

• [[yii\data\Sort::$attributes|attributes]] specifies the attributes by which the data can be sorted. An attribute can be as simple as a model attribute. It can also be a composite one by combining multiple model attributes or DB columns. More details will be given in the following.
• [[yii\data\Sort::$attributeOrders|attributeOrders]] gives the currently requested ordering directions for each attribute.
• [[yii\data\Sort::$orders|orders]] gives the ordering directions in terms of the low-level columns.

Pagination

When there are too much data to be displayed on a single page, a common strategy is to display them in multiple pages and on each page only display a small portion of the data. This strategy is known as pagination.

Yii uses a [[yii\data\Pagination]] object to represent the information about a pagination scheme. In particular,

• [[yii\data\Pagination::$totalCount|total count]] specifies the total number of data items. Note that this is usually much more than the number of data items needed to display on a single page.
• [[yii\data\Pagination::$pageSize|page size]] specifies how many data items each page contains. The default value is 20.
• [[yii\data\Pagination::$page|current page]] gives the current page number (zero-based). The default value is 0, meaning the first page.

Data Formatting

To display data in a more readable format for users, you may format them using the formatter application component. By default the formatter is implemented by [[yii\i18n\Formatter]] which provides a set of methods to format data as date/time, numbers, currencies, and other commonly used formats. You can use the formatter like the following,