e9e2786fa3
Rather than returning a modified copy of the input params/defaults, always return a new object, copying the appropriate values into it. https://bugzilla.gnome.org/show_bug.cgi?id=608667
35 lines
1.1 KiB
JavaScript
35 lines
1.1 KiB
JavaScript
/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
|
|
|
|
// parse:
|
|
// @params: caller-provided parameter object, or %null
|
|
// @defaults: function-provided defaults object
|
|
// @allowExtras: whether or not to allow properties not in @default
|
|
//
|
|
// Examines @params and fills in default values from @defaults for
|
|
// any properties in @defaults that don't appear in @params. If
|
|
// @allowExtras is not %true, it will throw an error if @params
|
|
// contains any properties that aren't in @defaults.
|
|
//
|
|
// If @params is %null, this returns the values from @defaults.
|
|
//
|
|
// Return value: a new object, containing the merged parameters from
|
|
// @params and @defaults
|
|
function parse(params, defaults, allowExtras) {
|
|
let ret = {}, prop;
|
|
|
|
if (!params)
|
|
params = {};
|
|
|
|
for (prop in params) {
|
|
if (!(prop in defaults) && !allowExtras)
|
|
throw new Error('Unrecognized parameter "' + prop + '"');
|
|
ret[prop] = params[prop];
|
|
}
|
|
|
|
for (prop in defaults) {
|
|
if (!(prop in params))
|
|
ret[prop] = defaults[prop];
|
|
}
|
|
|
|
return ret;
|
|
} |