How DoenetML works

Definitions: Components, Attributes, and Properties

DoenetML is a markup language much like HTML. When creating content in DoenetML, you are essentially working with 3 types of data objects:

Components - also called “tags” informally, describe the type of content that is being defined or rendered. Typically, a component will consist of an opening tag <componentName> and a closing tag </componentName>, with content, content specifications, or other components occuring between these two tags. Some components, if they do not require additional information, may be self-closing, <componentName/>.
Attributes - provide information necessary to define the component’s desired behavior within the opening tag. The syntax for specifying an attribute is: <componentName attr="value">.
Properties (or Props) - props are stored information relating to a component that may be accessed by referencing the component by name, followed by the name of the property.

Example: Illustration of components, attributes and properties

The available attributes and properties vary by component. See the Component Examples section for a full listing for each.

Component Types

The components in DoeneML can be categorized into several functional types that characterize their most common use-case and functionality. The system presented here is not a formal, programmatic characterization; it is intended to mainly help authors of DoenetML find and select useful components when building activities, and to make learning components easier.

To see a list of components organized by type, see the Index by Component Type page.

The different types are:

Type of Component	Description
Paragraph Markup	used within a paragraph, or `<p>` tag to change the way text is rendered
Sectional	used to structure content on the page; may have auto-numbering
Input	used to gather user-input, such as text-boxes, multiple-choice selections, or checkboxes
Graphical	used to render interactive elements on a graph
Display Math	used to render LaTeX; does not invoke the CAS
Math	used to define mathematical content; can be symbolic or numerical
Math Operator	used to perform mathematical operations
General Operator	used to perform operations on math and non-math components
Logic	used to define boolean conditions
Evaluation	used with answer validation and awarding of credit
Text	any component that uses text strings outside the context of a paragraph

Some components may belong to more than one functional type, such as a <sequence>, which can generate either a numerical or a text sequence, or a <mathInput> which collects student’s mathematical responses and also stores the value as a Math Component for use in computations by the CAS.

The Computer Algebra System (CAS)

DoenetML is linked to a CAS which performs the basic computations necessary for the behavior of mathematical and graphical components, as well as answer-checking.

All Math Components and Graphical Components have access to the CAS, which can be used when evaluating or responding to user interactions with these components. For example, when a user drags a <line>, dilates a <circle>, or updates the coefficient in an equation via a <mathInput>, the CAS instantaneously updates all of the stored property data relating to that component.

Mathematical Display components, by contrast, do not access the CAS.

Basic Language syntax

Components can communicate information between one another by means of references. To create a reference, attach a name attribute to a defined component following the DoenetML naming convention.

Naming conventions

DoenetML naming convention:

Can only contain numbers, letters, and underscores
Cannot start with an underscore or a number
Is case-sensitive

When you need to access the value of the named component or one of its stored properties, use the notation $componentName to create a reference to the component itself, and use the notation $componentName.propertyName to create a reference to one of its properties.