Add ability to use a brandImage with the navbar

[Ariestattoo]

Bootstrap Navbar allows the use of an image in the navbar instead of txt
http://getbootstrap.com/components/#navbar-brand-image

Simple addition of the property and code allows this enhancement, I have a fix to push however it does dig the hole deeper for issue #164
http://getbootstrap.com/components/#navbar-brand-image

 if ($this->brandImage !== false) {
            Html::addCssClass($this->brandOptions, ['widget' => 'navbar-brand']);
            echo Html::a(Html::img($this->brandImage), $this->brandUrl === false ? Yii::$app->homeUrl : $this->brandUrl, $this->brandOptions);
        }

Q	A
Yii vesion	2.1
PHP version	7.1
Operating system	Ubuntu 16.04

[razvanphp]

I want to prepare a PR for extending this part of the code, in my case I would like to add some HTML search form in navbar-header div, currently this is not configurable, can you please advise how to do it?

Should I create a new property $headerContent? Or make the whole brand part configurable, so we can use link, image or custom HTML?

[cebe]

I'd add both, $brandImage and $headerContent.

$brandImage will override $brandLabel if set and render a link with an image instead of label.

$headerContent will be rendered after the navbar-brand.