1. Adding List Page

In Unit 2.4 we created the CRUD pages automatically with Inferencer, and now we will do it manually by using the code generated by Inferencer to customize those pages freely.

Creating the list page

First, we need to create our file, named list.tsx, under the src/pages/blog-posts folder. We will then copy the list page code generated by Inferencer and paste it into the file; for this, follow these steps:

1. Navigate to localhost:3000/blog-posts in your browser.

2. Click on the "Show Code" button in the bottom right corner of the page.

3. You will see the list page code that was generated by Inferencer. Copy it by clicking on the "Copy" button.

4. Paste the code into the newly created list.tsx file.

You can see an example list page generated by Inferencer below:

http://localhost:3000/blog-posts

Understanding the List Component

Hooks and Components in List Page

• <List/> is a refine component that is used for presentation purposes like showing the create button, page title etc.

  For more information, refer to the <List/> documentation→

• <DataGrid/> is a native Material UI component that is used to display the data in a tabular format.

  For more information, refer to the Material UI <DataGrid/> documentation→

• The useDataGrid hook, imported from @refinedev/mui package, has all the features of the useTable hook. It fetches data from API and provides helper hooks for the <DataGrid> component. It also offers features like sorting, filtering, and pagination with just one line of code and returns necessary values in the dataGridProps variable.

  For more information, refer to the useDataGrid documentation→

• <EditButton/> and <ShowButton/> are refine components that are used to navigate to the edit and show pages of the record, respectively.

  For more information, refer to the <EditButton/> and <ShowButton/> documentations→

Handling Relationships

Each blog post includes the category field, which has an id property. This is a foreign key that points to the categories resource, which is different from the "blog_posts" resource.

There is a title field in the categories resource; to display it in the table, we can use the useMany hook provided by refine.

This hook allows us to fetch data for multiple records in a single request by providing the id's of the related records. In this case, we need to provide the id's of the blog posts categories. It is particularly useful when we need to fetch related data for multiple records.

In the code below, each blog post record has a category field:

https://api.fake-rest.refine.dev/blog_posts

{
  ...
  "category": {
    "id": 1
  }
  ...
},
{
  ...
  "category": {
    "id": 2
  }
  ...
}

We can use the useMany hook to fetch the full category records for each of these blog posts like this:

import { useMany } from "@refinedev/core";

const { data } = useMany({
    resource: "categories",
    ids: blogPosts.map((blogPost) => blogPost.category.id),
});

This will pass the resource and ids to the dataProvider's getMany function. The dataProvider will then make a single request to the API to fetch the full records for each category related to the blog posts. The resulting data variable will be an array of category records, like this:

[
    {
        id: 1,
        title: "mock category title",
    },
    {
        id: 2,
        title: "another mock category title",
    },
];

We can then use this data array to display the title of each category in the table.

For more information, refer to the useMany documentation→

Adding the List Page to the App

Now that we have created the list page, we can add it to the App.tsx file:

1. Open src/App.tsx file on your editor.

2. Import the created BlogPostList component.

3. Replace the MuiInferencer component with the BlogPostList component.

src/App.tsx

import { CssBaseline, GlobalStyles, ThemeProvider } from "@mui/material";
import { Refine } from "@refinedev/core";
import { MuiInferencer } from "@refinedev/inferencer/mui";
import {
    ErrorComponent,
    ThemedLayoutV2,
    RefineThemes,
    notificationProvider,
    RefineSnackbarProvider,
} from "@refinedev/mui";
import routerBindings, { NavigateToResource } from "@refinedev/react-router-v6";
import dataProvider from "@refinedev/simple-rest";
import { BrowserRouter, Outlet, Route, Routes } from "react-router-dom";

import { BlogPostList } from "pages/blog-posts/list";

const App: React.FC = () => {
    return (
        <ThemeProvider theme={RefineThemes.Blue}>
            <CssBaseline />
            <GlobalStyles styles={{ html: { WebkitFontSmoothing: "auto" } }} />
            <RefineSnackbarProvider>
                <BrowserRouter>
                    <Refine
                        routerProvider={routerBindings}
                        dataProvider={dataProvider(
                            "https://api.fake-rest.refine.dev",
                        )}
                        notificationProvider={notificationProvider}
                        resources={[
                            {
                                name: "blog_posts",
                                list: "/blog-posts",
                                show: "/blog-posts/show/:id",
                                create: "/blog-posts/create",
                                edit: "/blog-posts/edit/:id",
                            },
                        ]}
                    >
                        <Routes>
                            <Route
                                element={
                                    <ThemedLayoutV2>
                                        <Outlet />
                                    </ThemedLayoutV2>
                                }
                            >
                                <Route
                                    index
                                    element={
                                        <NavigateToResource resource="blog_posts" />
                                    }
                                />

                                <Route path="blog-posts">
                                    <Route index element={<BlogPostList />} />
                                    <Route
                                        path="show/:id"
                                        element={<MuiInferencer />}
                                    />
                                    <Route
                                        path="edit/:id"
                                        element={<MuiInferencer />}
                                    />
                                    <Route
                                        path="create"
                                        element={<MuiInferencer />}
                                    />
                                </Route>

                                <Route path="*" element={<ErrorComponent />} />
                            </Route>
                        </Routes>
                    </Refine>
                </BrowserRouter>
            </RefineSnackbarProvider>
        </ThemeProvider>
    );
};
export default App;

Now, we can see the list page in the browser at localhost:3000/blog-posts

Checklist

I have added the list page to the app.

I understood the list page components and hooks.

I understood the relationship handling.