18-helper-method-overrides.md

layout	title	permalink	redirect_from	blacklight_version
page	Helper method overrides	/v7.11.1/helper-method-overrides/	/overrides/	v7.11.1

Much of Blacklight is written in a way that is overridable, helper methods are no different.

Let's take a look at the module that is used to help with some of the layout for Blacklight. This module is mixed into the Blacklight::BlacklightHelperBehavior which allows us to override methods mixed in.

For example, the html_tag_attributes method is used to inject HTML tag attributes into the main Blacklight layout.

{% highlight ruby %}

Attributes to add to the tag (e.g. lang and dir)

@return [Hash]

def html_tag_attributes { lang: I18n.locale } end {% endhighlight %}

Default HTML attributes

If we want to modify this method to return something different, we first need to create the CustomLayoutHelper module in our local application.

{% highlight bash %} $ touch app/helpers/custom_layout_helper.rb {% endhighlight %}

And then within custom_layout_helper.rb we need to include the Blacklight::LayoutHelperBehavior mixin.

{% highlight ruby %}

app/helpers/custom_layout_helper.rb

module CustomLayoutHelper include Blacklight::LayoutHelperBehavior end {% endhighlight %}

Now we are free to override methods to meet our custom application needs. For example, lets override the html_tag_attributes method.

{% highlight ruby %}

app/helpers/custom_layout_helper.rb

module CustomLayoutHelper include Blacklight::LayoutHelperBehavior

Overriden to include dir

def html_tag_attributes super.merge(dir: 'rtl') end end {% endhighlight %}

This overridden method adds an additional attribute dir="rtl" to display our page right-to-left. While this is not a fully sufficient solution to implementing right-to-left behavior in your site, it does demonstrate how this helper can be extended.

Custom HTML attributes

This is just one way that the Blacklight code can be overridden and customized. Similar patterns can be used to customize controllers and search behavior.

For more information about overriding helpers, checkout the Blacklight Wiki.