Iterate through properties of current context objects in Dust.js - dust.js

Question

Given the JSON object:
errors =
{
hashed_password: {
message: 'Validator "Password cannot be blank" failed for path hashed_password',
name: 'ValidatorError',
path: 'hashed_password',
type: 'Password cannot be blank' },
username: {
message: 'Validator "Username cannot be blank" failed for path username',
name: 'ValidatorError',
path: 'username',
type: 'Username cannot be blank' },
email: {
message: 'Validator "Email cannot be blank" failed for path email',
name: 'ValidatorError',
path: 'email',
type: 'Email cannot be blank' },
name: {
message: 'Validator "Name cannot be blank" failed for path name',
name: 'ValidatorError',
path: 'name',
type: 'Name cannot be blank' }
}
How do I iterate through the properties of each "current context" object?
I would think you do something like this:
{#errors}
{#.}
{type}
{/.}
{/errors}

Answer 1

If you really have to put meaningful data into object keys, consider writing a contextual helper, as per:
https://github.com/akdubya/dustjs/issues/9
Dust.js output JSON key

Answer 2

It is not possible to iterate through members of an object in Dust. Part of the reason is that you cannot know the order of the members. Another part is that this is seen as bringing too much logic into Dust.
Instead, you can change the JSON to look more like this:
{
errors: [
{
hashed_password: {
message: 'Validator "Password cannot be blank" failed for path hashed_password',
name: 'ValidatorError',
path: 'hashed_password',
type: 'Password cannot be blank'
}
},
{
username: {
message: 'Validator "Username cannot be blank" failed for path username',
name: 'ValidatorError',
path: 'username',
type: 'Username cannot be blank'
}
},
{
email: {
message: 'Validator "Email cannot be blank" failed for path email',
name: 'ValidatorError',
path: 'email',
type: 'Email cannot be blank'
}
},
{
name: {
message: 'Validator "Name cannot be blank" failed for path name',
name: 'ValidatorError',
path: 'name',
type: 'Name cannot be blank'
}
]
}

Answer 3

You can iterate over an object using a helper.
For example, you could define a helper like this one:
dust.helpers.iter = function(chunk, context, bodies, params) {
var obj = dust.helpers.tap(params.obj, chunk, context);
var iterable = [];
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
var value = obj[key];
iterable.push({
'$key': key,
'$value': value,
'$type': typeof value
});
}
}
return chunk.section(iterable, context, bodies);
};
Then, in your template, you would loop through like this:
{#iter obj=errors}
{$value.type}
{/iter}