如何在节点JS中使用facebook messenger发送图像API？

Question

我正在用facebook信使API在nodejs中构建一个facebook机器人。我试图通过直接上传heroku服务器本身的图像文件（而不是通过URL)，从机器人发送图像，但它不起作用。

以下是控制台的错误日志。

调用Send API 400错误请求失败{消息:'(#100)上载的文件数不正确。必须只上载一个文件。'，类型:'OAuthException'，代码:100，error_subcode:2018005，FBTrace_ID:'E32OGM/OFXD'}

官方的facebook文档只包含一个curl格式的示例，我不知道如何将这个curl复制成节点格式。

curl  \   -F 'recipient={"id":"recipientId"}' \   -F 'message={"attachment":{"type":"image", "payload":{}}}' \   -F 'filedata=@resource/pdf_img/sample.jpg;type=image/jpeg' \   "https://graph.facebook.com/v2.6/me/messages?access_token=PAGE_ACCESS_TOKEN"

//file_loc = __dirname+"/resource/pdf_img/sample.jpg"
function sendImageMessage(recipientId, file_loc){
    let fs = require('fs');
    var readStream = fs.createReadStream(file_loc);
    var messageData = {
        recipient : {
            id : recipientId
        },
        message : {
            attachment : {
                type : "image",
                payload :{}
            }
        },
        filedata:readStream
    }
    callSendAPI(messageData);
}
function callSendAPI(messageData) {
    request({
        uri: "https://graph.facebook.com/v2.6/me/messages",
        qs: {access_token: process.env.PAGE_ACCESS_TOKEN},
        method: "POST",
        json: messageData
    }, function(error, response, body) {
        if (!error && response.statusCode == 200) {
            var recipientId = body.recipient_id;
            var messageId = body.message_id;

            if (messageId) {
                console.log("Successfully sent message with id %s to recipient %s", 
                    messageId, recipientId);
            } else {
                console.log("Successfully called Send API for recipient %s", 
                    recipientId);
            }
        } else {
            console.error("Failed calling Send API", response.statusCode, response.statusMessage, body.error);
        }
    });
} 

请任何帮助修复我的节点实现或翻译卷曲到节点将不胜感激。

Answer 1

您可以在请求模块中使用forms/form-data/（它集成了模块'form-data')。但是所有的请求都需要严格化。因此，根据您的示例，以下内容应该完成该工作>>

function sendImageMessage(recipientId, file_loc){
    let fs = require('fs');
    var readStream = fs.createReadStream(file_loc);
    var messageData = {
        recipient : {
            id : recipientId
        },
        message : {
            attachment : {
                type : "image",
                payload :{}
            }
        },
        filedata:readStream
    }
    callSendAPI(messageData);
}

function callSendAPI(messageData) {
    var endpoint = "https://graph.facebook.com/v2.6/me/messages?access_token=" + process.env.PAGE_ACCESS_TOKEN;
    var r = request.post(endpoint, function(err, httpResponse, body) {
        if (err) {return console.error("upload failed >> \n", err)};
        console.log("upload successfull >> \n", body); //facebook always return 'ok' message, so you need to read error in 'body.error' if any
    });
    var form = r.form();
    form.append('recipient', JSON.stringify(messageData.recipient));
    form.append('message', JSON.stringify(messageData.message));
    form.append('filedata', messageData.filedata); //no need to stringify!
}

详情请参阅https://github.com/request/request#forms