Variable interpolation, that is, injecting context variables into the template output, is done with the {{ }} syntax:

<div>{{ some_value }}</div>

You can use a dot (.) to access attributes of a variable, but alternatively the so-called “subscript” syntax ([]) can be used. The following lines do the same thing:

{{ foo.bar }}
{{ foo['bar'] }}

It’s important to know that the curly braces are not part of the variable, but the print statement. If you access variables inside tags don’t put the braces around them.

If a variable or attribute does not exist you will get back an undefined value, which will render as nothing, evaluate to “false” in comparisons, and amount to 0 (zero) in numeric calculations.

In fact, there is a lot more you can do with variables; any valid Expression can be used in an interpolation, and Ginger’s expression language is quite powerful.

A Note On Values

Ginger is a dynamically typed language; conceptually, any Ginger value has at least a text representation and an HTML representation, but many values also support a list-like API, dictionary-style key-based access, or call-as-function semantics.

Ginger will pick the most suitable representation depending on context; this means that when you interpolate things into HTML templates, Ginger will either pick the HTML representation of the value, or, when that doesn’t exist, it will pick the plain-text representation and HTML-encode it.

You can override this behavior in a few ways:

• The |str filter (cf. Filters) forces Ginger to pick the text representation, even if a HTML representation exists. Typically, this will amount to stripping all markup from the HTML and retaining just the text content, however, values can implement this differently in order to produce a better textual representation.
• The |raw filter DISABLES HTML ENCODING ENTIRELY. This is normally dangerous, but there are sometimes exceptional cases where you have HTML source in a string, and you can be sure that it doesn’t contain any malicious / user-supplied data; the |raw filter can then be used to tell Ginger that the value is already HTML-encoded and can be considered “safe”.