第十周使用Lens创建一个去中心化的推特

官方资料 https://docs.alchemy.com/docs/how-to-create-a-decentralized-twitter-with-lens-protocol

关注我的推特(https://twitter.com/SoullessL) ，及时获取Alchemy 教程的最新信息。

初始化项目

进入https://replit.com/，如果没有账号，可以注册一个

点击创建一个Node.js的项目

创建成功以后在shell里输入如下代码，其中road-to-lens为你的项目名字，可以随意

npx create-next-app road-to-lens

输入成功以后，提示 'Ok to processed'，输入y，等待下载项目所需的安装包并创建项目。

然后我们在Shell里输入 cd road-to-lens 切换到项目所在路径下。

因为我们的项目是在一个子文件夹下面的，所以我们需要修改启动项

首先显示隐藏文件

然后我们打开.replit文件，删除原有内容，然后添加下面的两行内容，其中road-to-lens为你创建项目的名称

run = 'npm --prefix ./road-to-lens run dev'
entrypoint = './road-to-lens/pages/index.jsx'

然后我们点击“Run” 按钮，最终出现如上界面就是项目编译成功

代码更新

然后我们回到Shell里，输入命令 npm install @apollo/client graphql 安装graphql包。

然后我们回到road-to-lens文件夹下面，右键Add File，创建一个叫apollo-client.js的文件，并且在文件里面添加以下代码。

// ./apollo-client.js

import { ApolloClient, InMemoryCache } from "@apollo/client";

const client = new ApolloClient({
    uri: "https://api.lens.dev",
    cache: new InMemoryCache(),
});

export default client;

然后我们找到pages/_app.js文件，用以下代码替换文件内容

// pages/_app.js

import '../styles/globals.css'
import { ApolloProvider } from "@apollo/client";
import client from "../apollo-client";

function MyApp({ Component, pageProps }) {
  return (
    <ApolloProvider client={client}>
      <Component {...pageProps} />
    </ApolloProvider>
  );
}

export default MyApp

再找到pages/index.js，用以下代码替换文件内容

import { useQuery, gql } from "@apollo/client";

const recommendProfiles = gql`
  query RecommendedProfiles {
    recommendedProfiles {
          id
        name
        bio
        attributes {
          displayType
          traitType
          key
          value
        }
          followNftAddress
        metadata
        isDefault
        picture {
          ... on NftImage {
            contractAddress
            tokenId
            uri
            verified
          }
          ... on MediaSet {
            original {
              url
              mimeType
            }
          }
          __typename
        }
        handle
        coverPicture {
          ... on NftImage {
            contractAddress
            tokenId
            uri
            verified
          }
          ... on MediaSet {
            original {
              url
              mimeType
            }
          }
          __typename
        }
        ownedBy
        dispatcher {
          address
          canUseRelay
        }
        stats {
          totalFollowers
          totalFollowing
          totalPosts
          totalComments
          totalMirrors
          totalPublications
          totalCollects
        }
        followModule {
          ... on FeeFollowModuleSettings {
            type
            amount {
              asset {
                symbol
                name
                decimals
                address
              }
              value
            }
            recipient
          }
          ... on ProfileFollowModuleSettings {
          type
          }
          ... on RevertFollowModuleSettings {
          type
          }
        }
    }
  }
`;

export default function Home() {
  const {loading, error, data} = useQuery(recommendProfiles);

  if (loading) return 'Loading..';
  if (error) return `Error! ${error.message}`;

  return (
    <div>
      Hello
      {data.recommendedProfiles.map((profile, index) => {
        console.log(`Profile ${index}:`, profile);
        return (
          <div>
            <h1>{profile.name}</h1>
            <p>{profile.bio}</p>
            <div>{profile.attributes.map((attr, idx) => {
              if (attr.key === "website") {
                return <div><a href={`${attr.value}`}>{attr.value}</a><br/></div>
              } else if (attr.key === "twitter") {
                return <div><a href={`https://twitter.com/${attr.value}`}>@{attr.value}</a><br/></div>;
              }
              return(<div>{attr.value}</div>);
            })}</div>
          </div>
        );
      })}
    </div>
  )
}

然后我们回到road-to-lens下面，新建一个queries文件夹，并在下面新建一个recommendedProfilesQuery.js文件，然后在recommendedProfilesQuery.js下面添加如下代码。

// queries/recommendedProfilesQuery.js

import {gql} from '@apollo/client';

export default gql`
  query RecommendedProfiles {
    recommendedProfiles {
          id
        name
        bio
        attributes {
          displayType
          traitType
          key
          value
        }
          followNftAddress
        metadata
        isDefault
        picture {
          ... on NftImage {
            contractAddress
            tokenId
            uri
            verified
          }
          ... on MediaSet {
            original {
              url
              mimeType
            }
          }
          __typename
        }
        handle
        coverPicture {
          ... on NftImage {
            contractAddress
            tokenId
            uri
            verified
          }
          ... on MediaSet {
            original {
              url
              mimeType
            }
          }
          __typename
        }
        ownedBy
        dispatcher {
          address
          canUseRelay
        }
        stats {
          totalFollowers
          totalFollowing
          totalPosts
          totalComments
          totalMirrors
          totalPublications
          totalCollects
        }
        followModule {
          ... on FeeFollowModuleSettings {
            type
            amount {
              asset {
                symbol
                name
                decimals
                address
              }
              value
            }
            recipient
          }
          ... on ProfileFollowModuleSettings {
          type
          }
          ... on RevertFollowModuleSettings {
          type
          }
        }
    }
  }
`;

然后我们在road-to-lens文件夹下面，新建components文件夹，并且在文件夹下面新建一个名为Profile.js的文件，然后把下面的代码复制到文件里。

// components/Profile.js

import Link from "next/link";
export default function Profile(props) {
  const profile = props.profile;

  // When displayFullProfile is true, we show more info.
  const displayFullProfile = props.displayFullProfile;

  return (
    <div className="p-8">
      <Link href={`/profile/${profile.id}`}>
        <div className="max-w-md mx-auto bg-white rounded-xl shadow-md overflow-hidden md:max-w-2xl">
          <div className="md:flex">
            <div className="md:shrink-0">
              {profile.picture ? (
                <img
                  src={
                    profile.picture.original
                      ? profile.picture.original.url
                      : profile.picture.uri
                  }
                  className="h-48 w-full object-cover md:h-full md:w-48"
                />
              ) : (
                <div
                  style={{
                    backgrondColor: "gray",
                  }}
                  className="h-48 w-full object-cover md:h-full md:w-48"
                />
              )}
            </div>
            <div className="p-8">
              <div className="uppercase tracking-wide text-sm text-indigo-500 font-semibold">
                {profile.handle}
                {displayFullProfile &&
                  profile.name &&
                  " (" + profile.name + ")"}
              </div>
              <div className="block mt-1 text-sm leading-tight font-medium text-black hover:underline">
                {profile.bio}
              </div>
              <div className="mt-2 text-sm text-slate-900">{profile.ownedBy}</div>
              <p className="mt-2 text-xs text-slate-500">
                following: {profile.stats.totalFollowing} followers:{" "}
                {profile.stats.totalFollowers}
              </p>
            </div>
          </div>
        </div>
      </Link>
    </div>
  );
}

然后我们修改pages/index.js文件，把里面的内容替换为如下内容

import { useQuery, gql } from "@apollo/client";
import recommendedProfilesQuery from '../queries/recommendedProfilesQuery.js';
import Profile from '../components/Profile.js';

export default function Home() {
  const {loading, error, data} = useQuery(recommendedProfilesQuery);

  if (loading) return 'Loading..';
  if (error) return `Error! ${error.message}`;

  return (
    <div>
      {data.recommendedProfiles?.map((profile, index) => {
        console.log(`Profile ${index}:`, profile);
        return <Profile key={profile.id} profile={profile} displayFullProfile={false} />;
      })}
    </div>
  )
}

然后点击页面上面绿色的Run按钮把项目跑起来，预览大概如图所示，会有一些lens的数据，但是还没有样式。

然后我们回到Shell终端，输入下面的命令安装样式库 tailwindcss

npm install -D tailwindcss postcss autoprefixer

安装完再输入如下命令初始化tailwindcss

npx tailwindcss init -p

然后我们进入road-to-lens根目录，找到文件 tailwind.config.js，用以下的内容替换文件内容

// tailwind.config.js

module.exports = {
  content: [
    "./pages/**/*.{js,ts,jsx,tsx}",
    "./components/**/*.{js,ts,jsx,tsx}",
  ],
  theme: {
    extend: {},
  },
  plugins: [],
}

接着我们找到styles/globals.css文件，用以下内容替换文件内容。

html,
body {
  padding: 0;
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen,
    Ubuntu, Cantarell, Fira Sans, Droid Sans, Helvetica Neue, sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

* {
  box-sizing: border-box;
}

@media (prefers-color-scheme: dark) {
  html {
    color-scheme: dark;
  }
  body {
    color: white;
    background: black;
  }
}
/* ./styles/globals.css */
@tailwind base;
@tailwind components;
@tailwind utilities;

然后我们的界面大概是这样的。

然后我们再pages下面新建一个profile文件夹，然后在下面新建一个[id].js文件，这个页面用来显示用户的详情页，并在文件里添加如下内容

import { useQuery, useMutation } from "@apollo/client";
import { useRouter } from "next/router";
import fetchProfileQuery from "../../queries/fetchProfileQuery.js";
import Profile from "../../components/Profile.js";
import Post from "../../components/Post.js";

export default function ProfilePage() {
  const router = useRouter();
  const { id } = router.query;

  console.log("fetching profile for", id);
  const { loading, error, data } = useQuery(fetchProfileQuery, {
    variables: {
      request: { profileId: id },
      publicationsRequest: {
        profileId: id,
        publicationTypes: ["POST"],
      },
    },
  });

  if (loading) return "Loading..";
  if (error) return `Error! ${error.message}`;

  return (
    <div className="flex flex-col p-8 items-center">
      <Profile profile={data.profile} displayFullProfile={true} />
      {data.publications.items.map((post, idx) => {
        return <Post key={idx} post={post}/>;
      })}
    </div>
  );
}

然后我们在queries文件夹下面新增文件fetchProfileQuery.js，这个用来获取用户详情数据，并在文件里添加如下内容

import { gql } from "@apollo/client";

export default gql`
  query (
    $request: SingleProfileQueryRequest!
    $publicationsRequest: PublicationsQueryRequest!
  ) {
    publications( request: $publicationsRequest) {
      items {
        __typename
        ... on Post {
          ...PostFields
        }
        ... on Comment {
          ...CommentFields
        }
        ... on Mirror {
          ...MirrorFields
        }
      }
      pageInfo {
        prev
        next
        totalCount
      }
    }
    profile(request: $request) {
      id
      name
      bio
      attributes {
        displayType
        traitType
        key
        value
      }
      followNftAddress
      metadata
      isDefault
      picture {
        ... on NftImage {
          contractAddress
          tokenId
          uri
          verified
        }
        ... on MediaSet {
          original {
            url
            mimeType
          }
        }
        __typename
      }
      handle
      coverPicture {
        ... on NftImage {
          contractAddress
          tokenId
          uri
          verified
        }
        ... on MediaSet {
          original {
            url
            mimeType
          }
        }
        __typename
      }
      ownedBy
      dispatcher {
        address
        canUseRelay
      }
      stats {
        totalFollowers
        totalFollowing
        totalPosts
        totalComments
        totalMirrors
        totalPublications
        totalCollects
      }
      followModule {
        ... on FeeFollowModuleSettings {
          type
          amount {
            asset {
              symbol
              name
              decimals
              address
            }
            value
          }
          recipient
        }
        ... on ProfileFollowModuleSettings {
          type
        }
        ... on RevertFollowModuleSettings {
          type
        }
      }
    }
  }

  fragment MediaFields on Media {
    url
    mimeType
  }

  fragment ProfileFields on Profile {
    id
    name
    bio
    attributes {
      displayType
      traitType
      key
      value
    }
    isFollowedByMe
    isFollowing(who: null)
    followNftAddress
    metadata
    isDefault
    handle
    picture {
      ... on NftImage {
        contractAddress
        tokenId
        uri
        verified
      }
      ... on MediaSet {
        original {
          ...MediaFields
        }
      }
    }
    coverPicture {
      ... on NftImage {
        contractAddress
        tokenId
        uri
        verified
      }
      ... on MediaSet {
        original {
          ...MediaFields
        }
      }
    }
    ownedBy
    dispatcher {
      address
    }
    stats {
      totalFollowers
      totalFollowing
      totalPosts
      totalComments
      totalMirrors
      totalPublications
      totalCollects
    }
    followModule {
      ... on FeeFollowModuleSettings {
        type
        amount {
          asset {
            name
            symbol
            decimals
            address
          }
          value
        }
        recipient
      }
      ... on ProfileFollowModuleSettings {
        type
      }
      ... on RevertFollowModuleSettings {
        type
      }
    }
  }

  fragment PublicationStatsFields on PublicationStats {
    totalAmountOfMirrors
    totalAmountOfCollects
    totalAmountOfComments
  }

  fragment MetadataOutputFields on MetadataOutput {
    name
    description
    content
    media {
      original {
        ...MediaFields
      }
    }
    attributes {
      displayType
      traitType
      value
    }
  }

  fragment Erc20Fields on Erc20 {
    name
    symbol
    decimals
    address
  }

  fragment CollectModuleFields on CollectModule {
    __typename
    ... on FreeCollectModuleSettings {
      type
      followerOnly
      contractAddress
    }
    ... on FeeCollectModuleSettings {
      type
      amount {
        asset {
          ...Erc20Fields
        }
        value
      }
      recipient
      referralFee
    }
    ... on LimitedFeeCollectModuleSettings {
      type
      collectLimit
      amount {
        asset {
          ...Erc20Fields
        }
        value
      }
      recipient
      referralFee
    }
    ... on LimitedTimedFeeCollectModuleSettings {
      type
      collectLimit
      amount {
        asset {
          ...Erc20Fields
        }
        value
      }
      recipient
      referralFee
      endTimestamp
    }
    ... on RevertCollectModuleSettings {
      type
    }
    ... on TimedFeeCollectModuleSettings {
      type
      amount {
        asset {
          ...Erc20Fields
        }
        value
      }
      recipient
      referralFee
      endTimestamp
    }
  }

  fragment PostFields on Post {
    id
    profile {
      ...ProfileFields
    }
    stats {
      ...PublicationStatsFields
    }
    metadata {
      ...MetadataOutputFields
    }
    createdAt
    collectModule {
      ...CollectModuleFields
    }
    referenceModule {
      ... on FollowOnlyReferenceModuleSettings {
        type
      }
    }
    appId
    hidden
    mirrors(by: null)
    hasCollectedByMe
  }

  fragment MirrorBaseFields on Mirror {
    id
    profile {
      ...ProfileFields
    }
    stats {
      ...PublicationStatsFields
    }
    metadata {
      ...MetadataOutputFields
    }
    createdAt
    collectModule {
      ...CollectModuleFields
    }
    referenceModule {
      ... on FollowOnlyReferenceModuleSettings {
        type
      }
    }
    appId
    hidden
    hasCollectedByMe
  }

  fragment MirrorFields on Mirror {
    ...MirrorBaseFields
    mirrorOf {
      ... on Post {
        ...PostFields
      }
      ... on Comment {
        ...CommentFields
      }
    }
  }

  fragment CommentBaseFields on Comment {
    id
    profile {
      ...ProfileFields
    }
    stats {
      ...PublicationStatsFields
    }
    metadata {
      ...MetadataOutputFields
    }
    createdAt
    collectModule {
      ...CollectModuleFields
    }
    referenceModule {
      ... on FollowOnlyReferenceModuleSettings {
        type
      }
    }
    appId
    hidden
    mirrors(by: null)
    hasCollectedByMe
  }

  fragment CommentFields on Comment {
    ...CommentBaseFields
    mainPost {
      ... on Post {
        ...PostFields
      }
      ... on Mirror {
        ...MirrorBaseFields
        mirrorOf {
          ... on Post {
            ...PostFields
          }
          ... on Comment {
            ...CommentMirrorOfFields
          }
        }
      }
    }
  }

  fragment CommentMirrorOfFields on Comment {
    ...CommentBaseFields
    mainPost {
      ... on Post {
        ...PostFields
      }
      ... on Mirror {
        ...MirrorBaseFields
      }
    }
  }
`;

然后我们在components下面新建一个Post.js，并添加如下内容到文件中。

// components/Post.js
export default function Post(props) {
  const post = props.post;

  return (
    <div className="p-8">
      <div className="max-w-md mx-auto bg-white rounded-xl shadow-md overflow-hidden md:max-w-2xl">
        <div className="md:flex">
          <div className="p-8">
            <p className="mt-2 text-xs text-slate-500 whitespace-pre-line">
              {post.metadata.content}
            </p>
          </div>
        </div>
      </div>
    </div>
  );
}