如何正确地将网址分配给动作创建者 [英] How to properly assign a url as a prop to action creator

问题描述

我正在使用react-native-image-crop-picker和react-native-fetch-blob从相机胶卷中抓取图像，然后将其保存到Firebase存储桶中。

I'm using react-native-image-crop-picker along with react-native-fetch-blob to grab an image from the camera roll and then save it to a Firebase storage bucket.

class CreateForm extends Component {
  componentWillMount() {
   this.setState({ loading: false });
  }

  // RNFetchBlob and RNImageCropPicker working together to store an 
  // image in firebase, and then returning a url for that image.

  openImage() {
    this.setState({ loading: true });
    const Blob = RNFetchBlob.polyfill.Blob;
    const fs = RNFetchBlob.fs;
    window.XMLHttpRequest = RNFetchBlob.polyfill.XMLHttpRequest
    window.Blob = Blob
    //const uid = "12345"

    ImagePicker.openPicker({
      width: 300,
      height: 300,
      cropping: true,
      mediaType: 'photo',
    }).then(image => {
      const imagePath = image.path;

      let uploadBlob = null;

     const storage = firebase.storage();
     const storageRef = storage.ref();
     const imageRef = storageRef.child('dp.jpg');
     const mime = 'image/jpg';
     fs.readFile(imagePath, 'base64')
       .then((data) => {
          //console.log(data);
       return Blob.build(data, { type: `${mime};BASE64` });
    })
       .then((blob) => {
          uploadBlob = blob;
          return imageRef.put(blob, { contentType: mime });
       })
      .then(() => {
          uploadBlob.close();
          return imageRef.getDownloadURL();
       })

在以下代码段之前，一切都完美运行：

Everything works perfectly until this bit of code:

      .then((url) => {
          console.log(url);
          this.props.entryUpdate({ prop: 'image', url });
    });
   });
  }

它记录的URL很好。但是，当我尝试将此URL作为名为 image的道具分配给动作创建者 entryUpdate时，Firebase实时数据库会得到一个未定义的对象，并引发错误。

It logs the url just fine. But when I try to assign this url as a prop named 'image' to the action creator 'entryUpdate', the Firebase realtime database gets an undefined object and throws an error.

以下是动作创建者 entryUpdate：

Here's the action creator 'entryUpdate':

 export const entryUpdate = ({ prop, value }) => {
   return {
    type: ENTRY_UPDATE,
    payload: { prop, value }

  };
 };

没有图像属性，一切都将正确执行。因此，我知道我不会以某种方式为动作创建者提供正确的语法。

Without the 'image' prop, everything executes correctly. So I know that I'm not giving the action creator the right syntax somehow. The

this.props.entryUpdate({ prop: 'image', url });

行必须是完全错误的。任何帮助将不胜感激！

line has to be just plain wrong. Any help would be so appreciated!

推荐答案

问题是您正在错误地破坏传递给动作创建者的对象，（{道具，值}} 基本上是从要传递的对象中获取属性。 prop 是正确的，因为作为参数传递的对象具有 prop 键，并以 image作为值。但是 value 是未定义的，因为 value 不是作为参数传递的对象上的已定义键。改用 url 是正确的，应该可以解决您的问题：

The problem is you're destructuring the object being passed into the action creator incorrectly, ({ prop, value }) is basically grabbing the properties from the object being passed through. prop is correct because the object being passed as an argument has a prop key with 'image' as the value. value however is undefined because value is not a defined key on the object passed as an argument. Using url instead would be correct and should fix your issue:

export const entryUpdate = ({ prop, url }) => {
   return {
    type: ENTRY_UPDATE,
    payload: { prop, url } // or { prop, value: url } if you dont want to edit your dispatcher.

  };
 };

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