Allow specifying related data in a gridview data column

[cebe]

DataColumn uses ArrayHelper::getValue() which is now able to get related
data via relation.attribute syntax.

This feature was available in yii 1.1. and should also be in 2.0 imo

TODO:

• Documentation (will add docs when we agree to take this)

[coveralls]

Coverage increased (+0.04%) when pulling 543ca7a on cebe:gridview-related-data into 92a1bef on yiisoft:master.

[qiangxue]

I actually wanted to avoid introducing this syntax because it will come with side effects and in most cases it can be easily implemented with explicit expression. For example for DataColumn, when you use this expression, you will face the problem with how to specify the header label and how to sort the column. So this new syntax doesn't really save you much.

[rawtaz]

A common solution to the related attribute label "problem" is to define labels in the current class. For example:

• The related model Country's attribute 'name' has the label "Name" in that related class.
• If we were to use that label in the "main" model's context, we'd get a very misleading label for the field or whatever, since "Name" seems to be about the current/main model rather than the Country one.
• By adding an entry 'country.name'=>'Country' in the main model's attributeLabels(), this can be used whenever rendering a label or similar for the attribute 'country.name'.

So the label stuff should IMO be solved that way; Have Yii look for an attribute label for these "related notions" in the current class, and fall back on the one in the related class.

That said, there's definately the issue of related attributes not being sortable or filterable by default though, in Yii1. This is a super common thing that people ask how to do, and if we can solve it in Yii2 it wold be awesome.

[qiangxue]

@rawtaz Your proposed label resolution algorithm is something I want to avoid because it is a bit magical, error prone and may confuse users.

Besides the sorting issue, there's also another tricky issue: filtering. So basically with the introduction of notation x.y.z, we are not really bringing much benefit (with anonymous functions, it's easy and clear to get related attribute value for DataColumn.)

[cebe]

Current solution for displaying and sorting:

echo \yii\grid\GridView::widget(array(
    'dataProvider' => new \yii\data\ActiveDataProvider(array(
        'query' => \app\models\Invoice::find()->join('LEFT OUTER JOIN', 'customer', 'customer.id = invoice.customerId'),
        'sort' => array(
            'attributes' => array(
                'nr',
                'customerId' => array(
                    'asc' => array('customer.name' => Sort::ASC),
                    'desc' => array('customer.name' => Sort::DESC),
                ),
// ...
            )
        )
    )),
    'columns' => array(
        array(
            'attribute' => 'nr',
            'value' => function($data) { return empty($data->nr) ? '#'.$data->id : $data->nr; },
            'format' => 'text',
        ),
        array(
            'attribute' => 'customerId',
            'value' => function($data) { return $data->customer->name; },
        ),
// ...
    ),
));

[samdark]

Any decision about this one?

[cebe]

Not yet, will try to work on that later.

[DrMabuse23]

Hi, Is there any news about Sorting relations ?