Wash

A safe template rendering engine for Node.

Tutorial

A short sample code first:

var wash = require('wash');
 
var source = 
  'My name is {{ name }}. I am {{ age }} years old.\n' +
  '{% if age > 20 %}(Yes I am old enough.){% endif %}\n' +
  'I have {{ len(kids) }} kids. They are {{ join(kids, ", ") }}.\n' +
  'THEY ARE {% for k in kids %}{{ upper(k.value) }} {% endfor %}';
 
var context = {
  name: 'John',
  age: 30,
  kids: ['Daniel', 'Paul', 'Mark']
};
 
var output = wash.render(source, context);
 
console.log(output);

What wash does here is to render the input source string with the provided context variables.

• {{ name }} prints out the value of name variable (context.name). It becomes John in this example.
• {{ age }} does the same to age variable. But this time it's a number.
• {% if age > 20 %} ... {% endif %} prints (or execute) the string between if and endif tags only when name is above 20.
• {{ len(kids) }} prints the number of elements in kids collection. The collection can be an array or an object. In this example, kids is an array with 3 string elements. So this outputs 3.
• {{ join(kids, ", ") }} joins the elements of kids using separator of ", ".
• {% for k in kids %} ... {% endfor %} iterates kids collection. Inside this loop, you can access each element using k variable. So, {{ k.value }} evaluates to the value of the current element.
• {{ upper(k.value) }} converts the value of k to uppercase characters.

So, output will look like this.

My name is John. I am 30 years old.
I have 3 kids. They are Daniel, Paul, Mark.
THEY ARE DANIEL PAUL MARK 

For more details on the template syntax, please see Template Syntax below.

Why Wash?

Wash is safe. You can run untrusted template codes in Wash.

• Wash doew not allow the template code to access external variables, modules, or functions.
• Wash can restrict the number of iterations or the number of elements in collection.

References

• Template Syntax
• Using Wash

License

MIT license