How to process server side parameter sent from jquery datatables using Flask?

Question

I am having some issues in processing the parameters sent by jquery datatables 1.10 when server side processing is enabled. I initialized the datatable in the javascript side like this:

var table = $('#mytable').DataTable( {
                "processing": true,
                "serverSide": true,
                "ajax": {
                    'url': url,
                    'type': 'POST'
                },
                "columns": data
            } );

And receive the POST request in the Flask based server using this:

@app.route('/data/<data_key>', methods=['POST'])
def get_data(data_key):
    print request.form

    # do some processing here in order to filter data
    # ...

    return Response(json.dumps(data), status=200, mimetype='application/json')

In order to filter the data I tried to look inside request.form but the result is weird and can't be transformed easily to an array of objects. I get somthing like this:

ImmutableMultiDict(
[
('columns[0][data]', u'ReportDate'), 
('draw', u'1'),
('columns[1][name]', u''), 
('columns[1][data]', u'FundName'),
('columns[0][orderable]', u'true'), 
('columns[1][searchable]', u'true'), 
('columns[1][orderable]', u'true'), 
('order[0][column]', u'0'), 
('columns[0][name]', u''), 
('order[0][dir]', u'asc'), 
('search[value]', u''), 
('columns[1][search][regex]', u'false'), 
('columns[0][search][value]', u''), 
('search[regex]', u'false'), 
('columns[1][search][value]', u''), 
('columns[0][search][regex]', u'false'), 
('start', u'0'), 
('length', u'10'), 
('columns[0][searchable]', u'true')
]
)

In the jquery datatables documentation they say:

The order[i] and columns[i] parameters that are sent to the server are arrays of information:

order[i] - is an array defining how many columns are being ordered upon - i.e. if the array length is 1, then a single column sort is being performed, otherwise a multi-column sort is being performed.

columns[i] - an array defining all columns in the table.

In both cases, i is an integer which will change to indicate the array value. In most modern server-side scripting environments this data will automatically be available to you as an array.

However, Flask provide this data as a simple dictionary, is there a way to transform it to an array of objects easily?

Answer 1

Get DataTable to send json

ajax: {
    url: "/api/data_table",
    type: "POST",
    data: function ( args ) {
      return { "args": JSON.stringify( args ) };
    }
},

In flask, parse the json

args = json.loads(request.values.get("args"))
columns = args.get("columns")