Add Nunjucks filter to filter an array of data depending on the values of properties within it.

[gonogo]

Examples of usage:

• {% for tx in data.transactions | filterObjects('type', 'is not', 'submission') | sort(true, false, 'lastUpdated') %}
• {% for tx in data.users | filterObjects('role', 'is', 'admin') %}

Thanks to @igloosi for this contribution.

[NickColley]

As I mentioned in the previous pull request we've not currently got clear evidence that our users need this feature.

I'm going to close this out for now, but will use it as a reference if we get more people asking for this, then we can re-open :)

Thanks again.

[edwardhorsford]

I created a similar filter to this recently - I wanted to filter an array of objects to only those that had an attribute of a certain value. It would have been useful to have it built in.

Mine only tested for whether the value equals the test item:

// filter results for only those containing attr/ var
  filters.filterAttr = function (arr, attr, test) {
    var result = arr.filter(function (item) {
       return item[attr] === test;
    });
    return result
  };