I have followed the Facebook documentation to request access token and post to a Facebook Page.

Now, I wish to create a post and attach some photos to that post but Facebook is only posting the text body and not including the photo files.

Here is how I did it:

   ...
    let mediaIds = [];
    for (let photoUrl of photoUrls) {
        let mediaUploadUrl = `https://graph.facebook.com/${pageId}/photos?url=${photoUrl}&access_token=${pageAccessToken}`;
        let response = await axios.post(mediaUploadUrl);
        let { id } = response.data;
        if (id) {
            mediaIds.push(id);
        }
    }

    // Now that we have the mediaIds, let's attach them to the post as below:

    let urlParams = new URLSearchParams();
    urlParams.append("access_token", pageAccessToken);
    urlParams.append("message", "Hello World");
    
    let postUrl = `https://graph.facebook.com/${pageId}/feed`;

    if (mediaIds.length > 0) {
        for (let i = 0; i < mediaIds.length; i  ) {
            let mediaId = mediaIds[i];
            let mediaIdObject = { media_fbid: mediaId };
            urlParams.append(`attached_media[${i}]`, mediaIdObject);
        }
    }
    
    try {
        let { data } = await axios.post(postUrl, urlParams);
        let postId = data.id;
    } catch (e) {
        done = false;
        console.log(e); //An unknown error has occurred is the error message I keep getting
    }
    ...

All I keep getting in return is

An unknown error has occurred

But if I go to the Facebook Page, I noticed the text body was posted but not the photo attachments.

Any ideas on fixing this would be really appreciated.

CodePudding user response：

Appending an object to urlParams, as you do in

let mediaIdObject = { media_fbid: mediaId };
urlParams.append(`attached_media[${i}]`, mediaIdObject);

produces a URL parameter like

attached_media[0]=[object Object]

Use

urlParams.append(`attached_media[${i}]`, JSON.stringify(mediaIdObject));

instead.