A blazor webassembly application that can automatically generate page components based on objects or types

A component that can automatically generate pages based on objects or types Blazor WebAssembly application

• Github ma-hua/blazor-auto
• be based on Ant.Design-Blazor Component library
• need dotnet-sdk v3.1.6 And above
  
  

Requirements describe

• Business requirements related to promotional activities often change frequently , be based on Sql Server in json Storage technology , Reconstruct the original system of the company . Divide the activity rules into several categories , The objects of each class are no longer stored in the database in the way of corresponding fields , But rather Json How to store , When you need to add or delete some fields , Just modify the corresponding entity , Without modifying the database design .
• After that, new requirements are put forward for the activity management system , That is, according to the newly released Nuget package , Auto generate rule settings page . be based on html+js Our front-end technology may not be able to do this , Therefore, it is proposed to use Blazor technology +C#, To achieve this goal ： Automatically generate page components according to objects or types , And complete data binding , To complete operations such as adding or editing .

Project introduction

This project is for reference only , I'm not very talented , Please give more advice on the shortcomings

• Blazor.Auto Including reflection, field description and other related tools
• Blazor.Auto.Components A component library that automatically completes data binding based on field descriptors （ be based on Ant.Design-Blazor）

Get the main information of the field

• Field descriptors FieldDescriptor    Contains the field name , Field description ,IsRequired, Value descriptor
• Value descriptor ValueDescriptor   The type that contains the value , value , Drop down list

Field component ： Input box   Date Pickers   switch   List selector

• According to the value type , The input fields are divided into ： String input box , Integer input box , Decimal input box
• Switches are divided into controllable switches and non empty switches （bool? and bool Two kinds of ）
• The list selector is displayed as a modal box , It is divided into single choice list and multi choice list

   Field components are inherited from the parent component BaseComponent, The parent component contains virtual methods ValueChangedCallBack, Complete parameter binding in the way of link binding .

List selector

   List selectors usually correspond to types List<T> Field of , The acquisition of selector content is critical . If the generic type is enumeration , You can get the selection list directly through reflection technology .

   But if you need to query some interfaces to get the selection list , Need to achieve ISelectItemProvider Interface . And specify a for its implementation class Keyword, Use properties on fields [SelectDescriptionAttribute] Mark the same Keyword. When generating components , Can pass Keyword from IOC Get... In the container SelectItemProvider, And call the implementation method , To get the options .

It is usually required to use Named Way of injection ISelectItemProvider Implementation class , In this project , I'm using Autofac Containers .

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
// Inject ISelectItemProvider Implementation class 
builder.ConfigureContainer(new AutofacServiceProviderFactory(cfg =>
    {
        cfg.RegisterAssemblyTypes(Assembly.GetExecutingAssembly());
        cfg.RegisterType<StoreGroupProvider>().Named<ISelectItemProvider>(StoreGroupProvider.Keyword).SingleInstance();
        cfg.RegisterType<PriceGroupProvider>().Named<ISelectItemProvider>(PriceGroupProvider.Keyword).SingleInstance();
    }));

In the list selector component , According to the Keyword from IOC Get the selection list item in the container

[Inject]
public IComponentContext ComponentContext { get; set; }

protected override async Task OnParametersSetAsync()
{
    if (!ValueComponentExtension.IsEnumSelect(Descriptor.Value) && !string.IsNullOrWhiteSpace(Keyword))
    {
        try
        {
            Items = await ComponentContext.ResolveNamed<ISelectItemProvider>(Keyword).GetSelectItemAsync();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
}