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node.jsibm-cloudnode-redwatson

In Node-RED, how do I upload to a node with the given configuration and retrieve the configuration later?


I am using Node-RED on Bluemix, I want to let the user upload a document, here is the relevant code fragment in a function/template of a flow

<form action="/upload" method="POST">
     <h1>Upload PDF</h1>
<input type="file" name="myFile" />
<input type="submit" />
</form>

When I run it, I chose a file and press 'submit', but then comes the message Cannot POST /upload Then I went to http://flows.nodered.org/node/node-red-contrib-http-multipart , in the example there it says


You can upload to a node with the following configuration:

[{ "name": "myFile" }]

and access the files using the following function on the out port of the node

var fields = msg.req.fields;
msg.fields = Object.keys(fields);
var myFile = fields["myFile"][0];
msg.localFilename = myFile.path
...

1) How can I upload a node with the configuration?

2)Once I get the file name, how do I retrieve it to be sent to the next services? -the next service is 'Conversion' - it takes in the file name.


Solution

  • To make it work, you need :
    1- a classic http node connected to a html node where you put your form :

    <form enctype="multipart/form-data" action="/fileUploaded" method="POST">
            <input type="file" name="myFile" />
            <input type="submit" />
    </form>
    

    2- Then you put your HTTP multipart node with Fields :

    [{ "name": "myFile"}]
    
    You link that node to a function node with the following code :
    var fields = msg.req.files;
    msg.fields = Object.keys(fields);
    var myFile = fields["myFile"][0];
    var fs = global.get('fs');
    var inStr = fs.createReadStream(myFile.path);
    var outStr = fs.createWriteStream('/app/public/upload/testUpload');
    inStr.pipe(outStr);
    msg.localFilename ='/upload/testUpload'
    return msg;
    

    You will need to have a folder named "upload" under /app/public/
    You will also need 'fs' :
    In bluemix-settings.js in functionGlobalContext add fs:require('fs')
    In package.json, add "fs":"x.x"
    The file will be copied there : /app/public/upload/testUpload
    Then we will be able to access it via msg.localFilename in the next node, for example in a HTML page like this :

    <html>
        <body>
            <h1>Job Done</h1>
            <a href=".{{localFilename}}">File uploaded here</a>
        </body>
    </html>