FIX Apply urldecode to querystring vars

[emteknetnz]

Fix for #133

I'm unsure about this approach because while it means that the space character can now be properly used in a filter value, the plus character can no longer be. It does seem pretty likely that space would be a far more used character than plus though

The developer who creates the custom report is required to put something like the following in their report for space to work (whether or not we merge this PR). Again, it has the same limitation that the space character can be used as part of a filter but not the plus character.

    public function sourceRecords($params = null)
    {
        array_walk_recursive($params, function(&$value) {
            $value = urldecode($value);
        });
        return MyModel::get()->filter($params);
    }

Sample code that can be used to test this PR:

MyModel.php

<?php

use SilverStripe\ORM\DataObject;

class MyModel extends DataObject
{
    private static $db = [
        'MyField' => 'Varchar'
    ];

    public function requireDefaultRecords()
    {
        parent::requireDefaultRecords();
        if (self::get()->count() > 0) {
            return;
        }
        $values = ['X', 'Y', 'A B', 'A+B'];
        foreach ($values as $value) {
            $record = self::create();
            $record->MyField = $value;
            $record->write();
        }
    }
}

MyReport.php

<?php

use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\TextField;
use SilverStripe\Reports\Report;

class MyReport extends Report
{
    public function title()
    {
        return 'My report';
    }

    public function sourceRecords($params = null)
    {
        array_walk_recursive($params, function(&$value) {
            $value = urldecode($value);
        });
        return MyModel::get()->filter($params);
    }

    public function columns()
    {
        return ['MyField' => 'MyField'];
    }

    public function parameterFields()
    {
        return new FieldList(
            new TextField('MyField', 'MyField')
        );
    }
}

[maxime-rainville]

You're not addressing the real problem here. The issue is the front end encodes A B as A%2BB when it should be encoded as A%20B. The problem is in ReportAdmin.js

$.path.addSearchParams and $.param seem to be using different approaches to encode/decode URL params.

I think you can bypass this problem by flattening your serialized params array into an object map like this:

/**
 * File: ReportAdmin.js
 */
(function($) {
  $.entwine('ss', function($){
	  $('.ReportAdmin .cms-edit-form').entwine({
		  onsubmit: function(e) {
        var url = $.path.parseUrl(document.location.href).hrefNoSearch,
          params = this.find(':input[name^=filters]').serializeArray();
        params = $.grep(params, function(param) {return (param.value);}); // filter out empty

        params = params.reduce(function (accmulator, item) {
          accmulator[item.name] = item.value;
          return accmulator
        }, {});

        if(params) url = $.path.addSearchParams(url, params);
        $('.cms-container').loadPanel(url);
        return false;
		  }
	  });
  });
})(jQuery);