Use a tax_query in a JSON REST API request

JSON REST API Tax Query

//requires authentication

add_filter('json_query_vars','accept_new_queries');
add_filter('json_query_var-tax_query', 'filter_by_taxonomy');

function accept_new_queries($filters){
	return array_merge($filters,array('tax_query'));
}

function filter_by_taxonomy($val){
	return maybe_unserialize(stripslashes($val));
}

//serialize the tax_query array to use in the URL
$tax_arrays = array(
	array(
		'field'=>'slug',
		'taxonomy'=>'designation',
		'terms'=>array('staff','student','alumni')
	)
)
$url = 'example.com/wp-json/posts?filter[tax_query]='.serialize($tax_arrays)';

Thanks! It helped a lot.

As I embedded the tax_query into a data attribute that I grab on the fly, so encoding the tax_query in base64 came very handy : http://davidwalsh.name/php-serialize-unserialize-issues

Cheers,