what does a specific method do in this open source solution

Question

Recently I'm trying to understand how NopCommerce plugins work.

I'll try to make my question as clear as possible and making sense for you without having the solution opened on your computer.

In nopCommerce plugins everything start with having a class which must have the definition for IWidgetPlugin interface and being derived from BasePlugin.

In one of the predefined plugins there is a class called NivoSliderPlugin and this class overrides some of it's base class methods and has the definition for IWidgetPlugin's methods.

here is the code:

    public class NivoSliderPlugin : BasePlugin, IWidgetPlugin 
    {

     // Here there are some fields that are referencing to different interfaces and then 
        they're injected to the class throw it's constructor
     
     // This method gets a configuration page URL
     public override string GetConfigurationPageUrl()
     {
        return _webHelper.GetStoreLocation() + "Admin/WidgetsNivoSlider/Configure";
     }

    }

In the above code I only mentioned the part of the code that I have a question about.

_webHelper is a reference to an interface and accept the incoming parameter of type bool.

Regardless the second part of the return, I mean the URL path which is "Admin/WidgetsNivoSlider/Configure", I'm wondering how _webHelper.GetStoreLocation() works ?

As you know _webHelper.GetStoreLocation() has no definition !

I hope what I just asked makes sense. If it's not clear please let me know to make it clearer. I'll appreciate it.

Answer 1

Let's start with IWidgetPlugin. This interface is not required to implement for all plugins in NopCommerce. This is required when you are developing a Widget type plugin. Here Nivo Slider is a widget type plugin, that's why it implemented IWidgetPlugin interface. Here is the implementation for Nivo slider.

/// <summary>
/// Gets a value indicating whether to hide this plugin on the widget list page in the admin area
/// </summary>
public bool HideInWidgetList => false;

/// <summary>
/// Gets a name of a view component for displaying widget
/// </summary>
/// <param name="widgetZone">Name of the widget zone</param>
/// <returns>View component name</returns>
public string GetWidgetViewComponentName(string widgetZone)
{
    return "WidgetsNivoSlider";
}

/// <summary>
/// Gets widget zones where this widget should be rendered
/// </summary>
/// <returns>
/// A task that represents the asynchronous operation
/// The task result contains the widget zones
/// </returns>
public Task<IList<string>> GetWidgetZonesAsync()
{
    return Task.FromResult<IList<string>>(new List<string> { PublicWidgetZones.HomepageTop });
}

If you want to develop a payment plugin, then you have to implement IPaymentMethod (i.e. PayPal, Stripe, Cash on Delivery) and IShippingRateComputationMethod for shipping methods (i.e. UPS, USPS). Also there are many other types of plugins available in nopCommerce. See the list below.

BasePlugin is an abstract class, which is required to be inherited for all plugin class. It has a virtual method named GetConfigurationPageUrl() which returns null by default. But this virtual method can be overridden from each plugin class and can return admin side configuration url for that plugin. Here is the overridden method for Nivo slider plugin.

/// <summary>
/// Gets a configuration page URL
/// </summary>
public override string GetConfigurationPageUrl()
{
    return _webHelper.GetStoreLocation() + "Admin/WidgetsNivoSlider/Configure";
}

Here _webHelper.GetStoreLocation() is a method which returns base url of the site. This method is implemented in Nop.Core.WebHelper class. The optional boolean parameter (useSsl) for this method is used whether to consider https:// or not for the site base url. If this method is overridden from a specific plugin, then a Configure button will be displayed in local plugin list page.