我正在尝试获取我的 Firestore 文档 ID

Question

我有一个需要连接到我的帖子（“想法”）的评论子集合，但是我无法将文档 ID 动态添加到我的 doc() 中。 由于没有其他解决方案，我目前将其留空。 因此，它正在生成一个新的文档 ID，而不是加入其父文档。

doc(post.id) 不起作用，因为 post 没有在我的 addComments 或 getComments 中定义，而只是 doc(id) 由于同样的原因而不起作用。

这是它目前正在做的事情

这就是我想要它做的。 出于演示目的，我手动输入了这篇文章的文档 ID：

这是我的 fire.js

  import FirebaseKeys from "./config/FirebaseKeys";
  import firebase from "firebase/app";
  import '@firebase/auth';
  import 'firebase/database';
  import '@firebase/firestore';
  import "firebase/storage";
  require("firebase/firestore");

 class Fire {
    constructor() {
    firebase.initializeApp(FirebaseKeys);
}

getPosts = async (displayLatestPost) => {
    const post = await this.firestore.collection('thoughts').orderBy('timestamp', 'desc').limit(10).get()
    
    let postArray =[]
    post.forEach((post) => {
        
        postArray.push({id: post.id, ...post.data()})
    })

  displayLatestPost(postArray)  
}

getComments = async (latestComment) => {
    const fetchedComment = await this.firestore.collection('thoughts').doc().collection('comments').orderBy('timestamp', 'desc').limit(10).get()

    let commentArray = []
    fetchedComment.forEach((comment) => {
       
        commentArray.push({id: comment.id, ...comment.data()})
    })
   console.log(" post id: " + post.id + "comment id: " + fetchedComment.id)
    latestComment(commentArray)
}


addPost = async ({ thoughtTitle, thoughtText, localUri, photoURL, displayName}) => {
    const remoteUri = await this.uploadPhotoAsync(localUri, `photos/${this.uid}/${Date.now()}`);
   

    return new Promise((res, rej) => {
        
         this.firestore
            .collection("thoughts")
            .add({
                uid: this.uid,
                displayName,
                photoURL,
                thoughtTitle,
                thoughtText,
                image: remoteUri,
                timestamp: this.timestamp,
                
            })
            .then(ref => {
                res(ref);
            })
            .catch(error => {
                rej(error);
            });
    });
};

 //comments
 addComments = async ({ displayName, photoURL, commentText}) => {


console.log("add a comment - post id:" )


return new Promise((res, rej) => {
    
     this.firestore
        .collection("thoughts")
        .doc()
        .collection('comments')
        .add({
            uid: this.uid,
            displayName,
            photoURL,
            commentText,
            timestamp: this.timestamp,
            
        })
        .then(ref => {
            res(ref);
        })
        .catch(error => {
            rej(error);
        });
   });
};
 //comments

uploadPhotoAsync = (uri, filename) => {
    return new Promise(async (res, rej) => {
        const response = await fetch(uri);
        const file = await response.blob();

        let upload = firebase
            .storage()
            .ref(filename)
            .put(file);

        upload.on(
            "state_changed",
            snapshot => {},
            err => {
                rej(err);
            },
            async () => {
                const url = await upload.snapshot.ref.getDownloadURL();
                res(url);
            }
        );
    });
};

createUser = async user => {
    let remoteUri = null;
    
    try {
        await firebase.auth().createUserWithEmailAndPassword(user.email, user.password);
        
        let db = this.firestore.collection("users").doc(this.uid);
    
        db.set({
            displayName: user.displayName,
            email: user.email,
            photoURL: null
        });
    
        if (user.photoURL) {
            remoteUri = await this.uploadPhotoAsync(user.photoURL, `avatars/${this.uid}`);
    
            db.set({ photoURL: remoteUri }, { merge: true });
        }
    } catch (error) {
        alert("Error: ", error);
    }
    };


    updateProfile = async user => {
        let remoteUri = null;
        
        try {
            let db = this.firestore.collection("users").doc(this.uid);
           
        
            db.update({
              displayName: user.displayName,
              photoURL: user.photoURL
            });
        
            if (user.photoURL) {
                remoteUri = await this.uploadPhotoAsync(user.photoURL, `avatars/${this.uid}`);
        
                db.set({ photoURL: remoteUri }, { merge: true });
            }
        } catch (error) {
            alert("Error: ", error);
        }  
        
        }


signOut = () => {
    firebase.auth().signOut();
};

get firestore() {
    return firebase.firestore();
}

get uid() {
    return (firebase.auth().currentUser || {}).uid;
}

get timestamp() {
     return Date.now();  
  }

 }

Fire.shared = new Fire();
export default Fire;

这是添加评论的屏幕。

import React from "react";
import { View, StyleSheet, Text, Image, ScrollView, TextInput, FlatList, 
TouchableOpacity} from "react-native";
import Fire from '../../Fire';

import CreatedAtText from '../../components/Text/CreatedAtText';

import Colors from  '../../constants/Colors';
import moment from 'moment';
import ThoughtCommentItem from '../../components/Thought/ThoughtCommentItem';
import FloatingButton from '../../components/UI/FloatingButton';




 export default class ThoughtDetailsScreen extends React.Component {
      state = {
     commentText: "",  
     latestComments: [],
     user: {
        photoURL: "",
        displayName: ""
    }
  
 };

 handleComment = () => {
    Fire.shared
        .addComments({  commentText: this.state.commentText.trim(), photoURL: this.state.user.photoURL, displayName: this.state.user.displayName })
        .then(ref => {
            this.setState({ commentText: ""});
        })
        .catch(error => {
            
            alert(error);
        });
};

displayLatestComment = (latestComments) => {
    this.setState({latestComments: latestComments});
   console.log("Latest Comments Details" + JSON.stringify(latestComments));
}

componentDidMount(){
   Fire.shared.getComments(this.displayLatestComment);
  
}

unsubscribe = null;

   componentDidMount() {
      const user = this.props.uid || Fire.shared.uid;


       this.unsubscribe = Fire.shared.firestore
          .collection("users")
          .doc(user)
          .onSnapshot(doc => {
           this.setState({ user: doc.data() });
       });
     }

   componentWillUnmount() {
      this.unsubscribe();
  } 


comment = () => {
    console.log("comment button clicked ")
  
 }

like = () => {
    console.log("like button clicked ")
  
}

fave = () => {
    console.log("fave button clicked ")
  
}



render(){
    
      const thought = this.props.navigation.getParam('thought');

 
   return(
      <View style={styles.container}>
   <ScrollView  style={{flex:1}}> 

  
       
    <Text>{thought.thoughtTitle}</Text>
    <Image style={styles.userAvatar} source={{uri: thought.photoURL}}/>
    <CreatedAtText style={styles.timestamp}> {moment(thought.timestamp).fromNow()}</CreatedAtText>
    <Text> User: {thought.displayName} </Text>
       <Image style={styles.headerPhoto} source={{uri: thought.image}}/>
    <Text>Main text: {thought.thoughtText}</Text>




 <View style={styles.commentsDisplay}>
   <FlatList
            showsVerticalScrollIndicator={false}
            keyExtractor={item => item.id}
            style={styles.feed}
            data={this.state.latestComments}
            renderItem={({item,index}) => {
                return ( 
                <ThoughtCommentItem
                photoURL={item.photoURL}
                displayName={item.displayName}
                timestamp={item.timestamp}
                commentText={item.commentText}
                onSelect={() => this.props.navigation.navigate('CommentDetails', {comment : item})}
                />
                );
            }

            } 
        />
     </View>


    <View style={styles.commentContainer}>
         <TextInput
           style={styles.commentBox}
           placeholder="Add your thoughts about this!"
           onChangeText={commentText =>this.setState({commentText})}
           defaultValue={this.state.commentText}
      />
     <Text onPress={this.handleComment} style={styles.commentButton}> Comment 
   </Text> 

   </View>
  

   </ScrollView>  
   <FloatingButton style={styles.floatingbutton}
   onSelectComment={this.comment}
   onSelectLike={this.like}
   onSelectFavorite={this.fave}
   />
   </View>

 );
 }
 };

 const styles = StyleSheet.create({
  container: {
    flex:1
},
commentContainer:{
    flexDirection: "row"
},
 headerPhoto : {
    height: 250,
    width: 200
},
userAvatar: {
    backgroundColor: Colors.subheadings,
    borderColor: Colors.accent,
    borderWidth:3.5, 

backgroundColor: Colors.maintext,
marginEnd: 15,
width: 35,
height: 35,
borderRadius: 20,
},
 floatingbutton:{
  bottom: 70,
  right: 60
 },
commentButton: {
   color: "#788eec",
    fontWeight: "bold",
    fontSize: 16
 },
commentsDisplay: {
   flex: 1,
   backgroundColor: Colors.background
 },
 feed : {
    marginHorizontal: 16

  }
});

Answer 1

正如您已经说过的，问题在于这段代码：

this.firestore
.collection("thoughts")
.doc()
.collection('comments')
.add({
    uid: this.uid,
    displayName,
    photoURL,
    commentText,
    timestamp: this.timestamp,
        

为了添加子集合或文档，您首先需要一个有效的参考，在这种情况下.doc()没有指定将包含子集合的文档。 这就是为什么你有上面的 output（截图），这就是为什么你的问题是“如何获取我的 Firestore 文档 ID”。

要动态获取 firestore 文档 id，您需要使用将生成文档 object 的查询，您需要遍历该文档以获取 id 属性，最后您将在.doc()中使用此 id 属性。

不用说，查询中使用的过滤器必须产生一个结果； 从您共享的代码中，我看到您可以使用 uid 作为过滤器。 以下是有关如何实现此目的的代码：

const firebase = require("firebase/app");
require("firebase/firestore");

firebase.initializeApp({
  projectId: 'project123'
});
var db = firebase.firestore();

function InsertSubcollection(collection,uid){

    db.collection(collection).where("uid", "==", uid).get()
        .then(function (querySnapshot) {
            let id =0;
            querySnapshot.forEach((doc) => id = doc.id);
            const docRef = db.collection('thoughts').doc(id).collection('comments');
            docRef.doc().add({
                name: "Sample123",
                test: true
              });
        })
        .catch(function (error) {
            console.log("Error getting documents: ", error);
        });
}

我希望这能有所启发。

如果您想了解有关 Firestore 查询的更多信息，请访问此。

Answer 2

抱歉，我没有发布找到的解决方案。

需要将此行添加到添加评论的屏幕 -

handleComment = () => {
        Fire.shared
            .addComments({  commentText: this.state.commentText.trim(), photoURL: this.state.user.photoURL, displayName: this.state.user.displayName, postID: this.props.navigation.state.params.thought.id })
            .then(ref => {
                this.setState({ commentText: ""});
            })
            .catch(error => {
                
                alert(error);
            });
    }; 

然后我必须将 postID 添加到我的 Fire.js addComments 中。

 addComments = async ({ displayName, photoURL, commentText, postID}) => {

    return new Promise((res, rej) => {
        
         this.firestore
            .collection("thoughts")
            .doc(postID)
            .collection('comments')
            .add({
                uid: this.uid,
                displayName,
                photoURL,
                commentText,
                timestamp: this.timestamp,
                
            })
            .then(ref => {
                res(ref);
            })
            .catch(error => {
                rej(error);
            });
    });
   };

所以基本上添加的代码行是：

postID: this.props.navigation.state.params.thought.id

和 -

 .doc(postID)

我真的希望这可以帮助有类似问题的人。