# File functionality

**URL:** <https://forums.losant.com/t/file-functionality/1017>\
**Category:** Help\
**Created:** [July 23, 2018, 3:15pm UTC](https://forums.losant.com/t/file-functionality/1017 "2018-07-23T15:15:53Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 3:15pm UTC](https://forums.losant.com/t/file-functionality/1017/1 "2018-07-23T15:15:54Z")

</div>

I have seen the File functionality being added recently. What are some of the api’s available to do the following.

Add directories  
Delete directories  
Add file  
delete file

I am not able to find any documentation on this.

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 4:27pm UTC](https://forums.losant.com/t/file-functionality/1017/2 "2018-07-23T16:27:01Z")

</div>

Thanks for bringing this to our attention! We had not updated the REST API documentation to include those new endpoints. The documentation is now there, and exists under the [https://docs.losant.com/rest-api/files/](https://docs.losant.com/rest-api/files/) and [https://docs.losant.com/rest-api/file/](https://docs.losant.com/rest-api/file/) pages.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 4:49pm UTC](https://forums.losant.com/t/file-functionality/1017/3 "2018-07-23T16:49:14Z")

</div>

Thanks. However, I do not see api’s for Add/delete directories.  
Also, what should be the ‘content-type’ to POST a image .png file?  
I do not see a fileID being returned not shown on the GUI. I see only the Name, lat updated and size being shown

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 5:01pm UTC](https://forums.losant.com/t/file-functionality/1017/4 "2018-07-23T17:01:48Z")

</div>

Directories are just a “type” of file - see the `type` property of the file POST schema ([https://docs.losant.com/rest-api/schemas/#file-post](https://docs.losant.com/rest-api/schemas/#file-post)) - so you create them the same way you would create a file, just with the `type` property set to `directory`.

The standard content type for for a png image is `image/png`.

Currently, the `id` of a file (or directory) is not shown in the user interface, because if you are just interacting with the user interface, the `id` is not particularly useful or meaningful. Since you are _also_ interacting through the API directly, I can see that value being useful - I’ll make a note that we should add it somewhere on the slide out properties pane.

Also, for regular files, after making the POST to Losant with the information about your file, you will get back (under the `upload` property in the response), a one-time use URL to upload the actual contents of the file to the Losant S3 File Store bucket. Your file will be marked as `pending` in the Losant interface until you actually use this URL to upload the contents of the file, at which point the file will be marked as `completed`.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 5:14pm UTC](https://forums.losant.com/t/file-functionality/1017/5 "2018-07-23T17:14:39Z")

</div>

I am not sure as to what to do with the one time URL I get. When I upload a image file within the GUI, I do not see “pending” - it gets completed and I can see the image. But not sure what I have to do when I do with API. My file uploaded is still in "wait’ state

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 5:22pm UTC](https://forums.losant.com/t/file-functionality/1017/6 "2018-07-23T17:22:00Z")

</div>

You use the one-time URL to upload the actual contents of the file. It is a pre-signed S3 upload URL ([https://docs.aws.amazon.com/AmazonS3/latest/dev/PresignedUrlUploadObject.html](https://docs.aws.amazon.com/AmazonS3/latest/dev/PresignedUrlUploadObject.html)). When you upload a file through the Losant interface, it is doing this in your browser for you (making the POST to Losant, getting the signed URL, and then using that signed URL to upload the file to S3).

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 5:25pm UTC](https://forums.losant.com/t/file-functionality/1017/7 "2018-07-23T17:25:59Z")

</div>

So why it is not doing the same way through API? why API users have to do this in two steps?

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 5:41pm UTC](https://forums.losant.com/t/file-functionality/1017/8 "2018-07-23T17:41:09Z")

</div>

The Losant user interface is using the API directly, just as you are trying to do. It is just doing that second step for you, in your local browser. The reason it works as this two step process is to create the optimal experience for the Losant user interface, where it is much faster to upload the file contents from the browser directly to S3 instead of passing those file contents through the Losant API and server infrastructure.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 5:49pm UTC](https://forums.losant.com/t/file-functionality/1017/9 "2018-07-23T17:49:30Z")

</div>

Undersrtood. Can you please help me with the API interface setup to AWS if I have to test it out in postman uploading to the onetime URL I obtained.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 5:52pm UTC](https://forums.losant.com/t/file-functionality/1017/10 "2018-07-23T17:52:13Z")

</div>

I tried to PUT against the onetime URL with all the field values. I get this error

\<?xml version="1.0" encoding="UTF-8"?\> `IllegalLocationConstraintException` The unspecified location constraint is incompatible for the region specific endpoint this request was sent to. F64DA43A6A8B2E16 v3dumHV9pBi3kMBYgMaT7UKZN//MvxVJlRIc39pUEGKhJ+8WVQjk5FXrFIRO7GYLNAq1eGnNHZU=

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 6:03pm UTC](https://forums.losant.com/t/file-functionality/1017/11 "2018-07-23T18:03:55Z")

</div>

When you make a files POST request to Losant, you will get back a JSON object with an `upload` field that has content similar to the following:

```auto
{
  "url": "https://s3.us-west-2.amazonaws.com/files.onlosant.com",
  "fields": {
    "Content-Type": "image/gif",
    "key": "5630dcbe1035c9d0011/file.js",
    "bucket": "files.onlosant.com",
    "X-Amz-Algorithm": "AWS4-HMAC-SHA256",
    "X-Amz-Credential": "AKIAJPGQGBQX4PYM6FXA/20180416/us-west-1/s3/aws4_request",
    "X-Amz-Date": "20180416T142402Z",
    "Policy": "a-large-policy-string",
    "X-Amz-Signature": "a-signature-string"
  }
}

```

In postman, you will want to make a POST to the value of the `url` property, and the post body should of type `multipart/form-data`. Every field in the `fields` object should be added to the post body _except_ for the `bucket` field. In addition, add one more field named `file`, which should be the actual file.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 6:22pm UTC](https://forums.losant.com/t/file-functionality/1017/12 "2018-07-23T18:22:19Z")

</div>

![image](https://us1.discourse-cdn.com/flex015/uploads/getstructure/original/1X/014186b194a4602b7078e7cd58d8ec1432b5bce1.png)

I have in the header Content-Type as multipart/form-data

I get this error

\<?xml version="1.0" encoding="UTF-8"?\> `MalformedPOSTRequest` The body of your POST request is not well-formed multipart/form-data. A68DA0066BCB833D xpeu/HlZMz6APWDvbC1Qk3cSA35cxPRBRqYd9oc5IMsNiwUXfgwP6oaUVv2vg3vmD8RiYOEnx98=

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 6:35pm UTC](https://forums.losant.com/t/file-functionality/1017/13 "2018-07-23T18:35:59Z")

</div>

I just made an attempt in Postman myself, to make sure there wasn’t anything I was missing, and my attempt succeeded:

 ![24%20PM](https://us1.discourse-cdn.com/flex015/uploads/getstructure/original/1X/bead8e5d0ab659ffc66198597acd830a1c9da233.png)

It doesn’t look like I explicitly have to set the multipart/form-data header, Postman does it for you, so if you are doing that, perhaps remove it?

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 23, 2018, 6:54pm UTC](https://forums.losant.com/t/file-functionality/1017/14 "2018-07-23T18:54:12Z")

</div>

so for the file field value in postman, I cannot give the reference of the filepath in Losant as in the key. Is this correct?

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 23, 2018, 7:02pm UTC](https://forums.losant.com/t/file-functionality/1017/15 "2018-07-23T19:02:24Z")

</div>

the “file” field in postman should be the actual file - in postman (at least my version), you say that it is a form field of type `file` and then it lets you browse for the file on your computer.

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 24, 2018, 12:46pm UTC](https://forums.losant.com/t/file-functionality/1017/16 "2018-07-24T12:46:24Z")

</div>

In postman it is easy to give the filename. But in an HTTP request, how do I give the file attribute the value of the filename. Is there any other key I need to specify to go with file attribute.

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 24, 2018, 3:09pm UTC](https://forums.losant.com/t/file-functionality/1017/17 "2018-07-24T15:09:56Z")

</div>

Are you looking for how to do this in javascript in a browser? If so, you can use the [FormData](https://developer.mozilla.org/en-US/docs/Web/API/FormData) class and the [File](https://developer.mozilla.org/en-US/docs/Web/API/File) class. You get back an instance of the `File` class from any HTML input field of type `file`, and you can hand such an instance to an instance of `FormData` when building your post request. For example, it could work something like the following:

```auto
var fileInstance = /* get the file instance from your form here */;
var formData = new FormData();
formData.append('file', fileInstance);
/* append the other required upload form fields here */
var xhr = new XMLHttpRequest();
xhr.open('POST', theUrlToUploadTo, true);
xhr.send(formData);

```

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 26, 2018, 2:15am UTC](https://forums.losant.com/t/file-functionality/1017/18 "2018-07-26T02:15:31Z")

</div>

Using formdata will not work for me as I will not be able to have an input type='file. I do not have a form to create in my gui interface.

I am trying to upload directly to the S3 bucket, that comes in the upload fields attribute([files.onlosant.com](http://files.onlosant.com)). What should be the AWS credentials settings should be.

I am trying like this … not sure as to what I should set for AWS config …

```
				AWS.config.region = 'us-west-2'; alert(AWS.config.region);
				AWS.config.accessKeyId = fields["X-Amz-Credential"];
				AWS.config.secretAccessKey = fields["X-Amz-Signature"];
				var bucket = new AWS.S3({params: {Bucket: 'files.onlosant.com'}});
                var blobData = dataURItoBlob(lnk.href);//alert("lnk.href=" + lnk.href);
                var fileName = fields["key"];
                var params = {Key: fileName, ContentType: fields["Content-Type"],Policy:fields["Policy"],'X-Amz-Algorithm':fields["X-Amz-Algorithm"],'X-Amz-Credential':fields["X-Amz-Credential"],'X-Amz-Date':fields["X-Amz-Date"],'X-Amz-Signature':fields["X-Amz-Signature"] ,Body: blobData};

```

alert("params = " + params[“X-Amz-Signature”]);  
bucket.upload(params, function (err, data) {  
console.log(err, data);  
console.log(err ? ‘ERROR!’ : ‘UPLOADED.’);  
});

dataURItoBlob is a function I am using to convert base64 data to a blob (like a file handle). My file is an image/png file.

Looks like my AWS config setting is not appropriate. Please let me know how to upload to S3 bucket

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<div class="post-metadata">

**Author:** ![Sreyams\_Jain1](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Sreyams\_Jain1](https://forums.losant.com/u/Sreyams_Jain1)\
**Post date:** [July 26, 2018, 2:40am UTC](https://forums.losant.com/t/file-functionality/1017/19 "2018-07-26T02:40:51Z")

</div>

My dataURItoBlob function is as below …

```auto
function dataURItoBlob(dataURI) {alert("in blob=" + dataURI.split(',')[1]);
    var binary = atob(dataURI.split(',')[1]);
    var array = [];
    for(var i = 0; i < binary.length; i++) {
        array.push(binary.charCodeAt(i));
    }
    return new Blob([new Uint8Array(array)], {type: 'image/png'});
}

```

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<div class="post-metadata">

**Author:** ![Michael\_Kuehl](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.losant.com/michael_kuehl/32/99_2.png) [@Michael\_Kuehl](https://forums.losant.com/u/Michael_Kuehl)\
**Post date:** [July 26, 2018, 2:57am UTC](https://forums.losant.com/t/file-functionality/1017/20 "2018-07-26T02:57:53Z")

</div>

`FormData` is still what you want to be using - if you read the [FormData Documentation](https://developer.mozilla.org/en-US/docs/Web/API/FormData/append), you will see that you can append a `Blob` to the form.

So something like the following should work:

```auto
var fileBlob = dataURItoBlob(lnk.href);
var formData = new FormData();
formData.append('file', fileBlob);
/* append the other required upload form fields here */
var xhr = new XMLHttpRequest();
xhr.open('POST', theUrlToUploadTo, true);
xhr.send(formData);

```

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