app.render(view, [locals], callback)
Returns the rendered HTML of a view via the callback function. It accepts an optional parameter
that is an object containing local variables for the view. It is like res.render(),
except it cannot send the rendered view to the client on its own.
Think of `app.render()` as a utility function for generating rendered view strings.
Internally `res.render()` uses `app.render()` to render views.
The `view` argument performs file system operations like reading a file from
disk and evaluating Node.js modules, and as so for security reasons should not
contain input from the end-user.
The `locals` object is used by view engines to render a response. The object
keys may be particularly sensitive and should not contain user-controlled
input, as it may affect the operation of the view engine or provide a path to
cross-site scripting. Consult the documentation for the used view engine for
additional considerations.
The local variable `cache` is reserved for enabling view cache. Set it to `true`, if you want to
cache view during development; view caching is enabled in production by default.
app.render('email', function (err, html) {
// ...
});
app.render('email', { name: 'Tobi' }, function (err, html) {
// ...
});