@nottimtam/file-converter
v1.2.19
Published
A headless, self-hostable, open-source file conversion express middleware.
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@nottimtam/file-converter
A headless, self-hostable, open-source file conversion express middleware.
Modules
This middleware can be extended with custom file conversion Modules
for unique use cases.
It does not ship o.o.t.b with any modules. Use @nottimtam/file-converter-core for core conversion modules.
GUI
While this package can be installed as a route on your express API, you can spin up a docker container with custom GUI for interfacing with the utility.
Installation and Setup
You can install this package with:
npm i @nottimtam/file-converter
You can implement this package on a route of your express API. Here is an example:
import express from "express";
import FileConverter from "@nottimtam/file-converter";
const app = express(); // Create express app.
const fileConverter = new FileConverter({
modules: [],
fileSizeLimit: 1086666,
temp: "./uploads/test",
});
// Middleware.
app.use(express.json());
app.use("/fcu", fileConverter.middleware()); // The route on which to access the file converter.
// Start app.
app.listen(3000, (err) => {
if (err) {
console.error(err);
} else {
console.log(`Server listening on port ${3000}.`);
}
});
Usage
FileConverter
Constructor
new FileConverter(config)
Create a new instance of the FileConverter
.
Parameters
- config:
Object
- An object containing configuration data.- modules:
Array<Module>
- Additional modules to expand the converter's functionality. - fileSizeLimit:
number
- A recommended (optional) limit for the total size of all files uploaded to the converter per request, in bytes. - temp:
string
- An optional path to a directory for temporary file storage. Defaults to"temp/"
in the local directory. Files are removed from this folder after they are converted. - clearJobOnDownload:
boolean
- (defaulttrue
) Auto-delete conversion jobs and their associated files after an api request has been made successfully to download the converted files. - DANGEROUSLYforceClearTemp:
boolean
- (defaultfalse
) Clear the content of the selectedtemp
directory on initialization. This WILL delete all files in the directory indiscriminately. Whenfalse
, the constructor will throw an error if the directory is not empty.
- modules:
Properties
All permitted properties defined in the constructor's config parameter are passed through to the constructed object.
jobs
An array of the converter's active jobs.
modules
An array of the converter's loaded modules.
stats
An object containing stats about the instance.
- initialization:
number
Milliseconds since the epoch, generated withDate.now()
. - filesConverted:
number
The number of files converted. - dataConverted:
number
The amount of data converted. (in megabytes)
Methods
middleware(req, res, next)
Get the file conversion express middleware function.
createJob(files, module, options)
Start a conversion job. This method is called by the express middleware to create file conversion jobs but could potentially be used in a custom environment.
- files:
Array<Object>
An array of file objects to convert. Should be a multer file object. - module:
Module
The module to convert with. - options:
Object
Optional options object configuration to pass to the module conversion job. Keys should be the label of each option configured in the module, and the values an appropriate value to set for that option. - options:
Object
Optional options object configuration to pass to the module conversion job. Keys should be the label of each option configured in the module, and the values an appropriate value to set for that option.
Returns
Job
: The created job.
Module
import { Module } from "@nottimtam/file-converter";
new Module(config)
Create a new file conversion module.
Parameters
- config:
Object
- An object containing configuration data.- from:
string | Array<string>
- The mimetype to convert from. Can be a single mimetype or an array of supported mimetypes. - to:
string
- The mimetype to convert to. - label:
string
- A unique label for this module. - description:
string
(optional) - A detailed description for the module. - method:
function
- An asynchronous callback that accepts a file object and converts that file's content, storing the converted data in the file at the providedpath
value. - options:
Array<Module.Option>
An array of options for conversion. - customReturn:
boolean
(optional) - By default, aModule
'sconvert
method will change the file data to match the conversion. Setting this totrue
makes themethod
callback return the "file" data passed to it, with necessary changes (e.g., changing file extension inoriginalname
). This also stops theModule
from throwing errors if theto
/from
mimetype values are invalid, allowing custom file types to be used.
- from:
Properties
All permitted properties defined in the constructor's config parameter are passed through to the constructed object.
_id
The module's UUID.
Methods
convertsFrom(mimetype)
Check if this module can convert files from a certain mimetype.
Parameters
- mimetype:
string
- The mimetype to check.
Returns
boolean
: Whether the mimetype is supported.
convertsTo(mimetype)
Check if this module can convert files to a certain mimetype.
Parameters
- mimetype:
string
- The mimetype to check.
Returns
boolean
: Whether the mimetype is supported.
async convert(files, callback)
Convert an array of files using the module's conversion method.
Parameters
- files:
Array<*>
- The array of files to convert. - callback:
function
(optional) - An asynchronous callback that is passed each file before/after it is converted.(old, new)
Returns
string
: The path to a zip file containing the converted files.
Module.Option
import { Module } from "@nottimtam/file-converter";
new Module.Option(config)
Create a new module Option
.
Parameters
- config: An object containing configuration data.
- label:
string
- A unique label for this option. - description:
string
(optional) - A detailed description for the option. - type:
"string"|"number"|"boolean"
- The option's input type. - default:
string|number|boolean
- (optional) The option's default value. - required:
boolean
- (optional) Whether or not to require a value to be provided for this option. Defaultfalse
, iffalse
, the option'svalidateInput
callback will not be run when no value is provided. - validateInput:
function
- An asynchronous callback function, used to validate the value provided to this option, which is passed as the first and only parameter. Should throw an exception if the value is invalid.
- label:
Properties
All permitted properties defined in the constructor's config parameter are passed through to the constructed object.
_id
The option's UUID.
Job
Jobs are not directly exposed through an export. They are created automatically within the new FileConverter().middleware()
method when a conversion request is made. They can also be created manually using new FileConverter().createJob()
.
Properties
_id
The job's UUID.
returnable
A specialized object that returns relevant Job data, useful for sending information about a job from a server to a client.
status
An object containing data on the status of the job.
**step**:
string` The current step of the job."pending"
: The job has not started."running"
: The job is in progress."done"
: The job has completed and the files can be downloaded."error"
: An uncaught error occured during the conversion process. Aerror
field is added to the status object in this case.
- filesConverted:
number
The number of files this job has converted.
files
An array of objects defining the files this job is responsible for.
module
The module the job will use for conversion.
options
The module options passed to the job.
Methods
async run(onStep)
Run the job.
- onStep:
function
An optional asynchronous callback to run when each step of the job is complete.onStep
is passed one argument, the job'sstatus
property.
API Reference
Routes
GET /
Get a simple API reference object.
GET /mimetypes
Get all valid file mimetypes.
Query Parameters
- type (optional): Filter by mimetype type. (the first part of a mimetype string, i.e., the
"text"
in"text/plain"
)
Example Response
{
"mimeTypes": [
"image/aces",
"image/apng",
"image/avci",
"image/avcs",
"image/avif",
"image/bmp"
// ...
]
}
GET /mimetypes/validate
Validate mimetype or file extension.
Query Parameters
- value (required): The value to validate.
Example Response
{
"valid": true, // A boolean indicating if the mimetype is valid.
"extension": "ez", // The file extension for this mimetype. (if valid)
"charset": false, // The charset for this mimetype. (if valid)
"contentType": "application/andrew-inset" // The content type of this mimetype. (if valid)
}
GET /modules
Get all file conversion modules.
Example Response
{
"modules": [] // An array of module information.
}
POST /convert
Convert file(s) from one filetype to another.
Body
- FormData:
- files: The file(s) to convert.
- module: The label of the module to convert the files with.
- options A stringified JSON object containing data for the selected Module's
config.options
configuration. The keys in the object should be eachOption
's label, and the value should be a proper formatstring
,number
, orboolean
. (ornull
when permitted)
Example Response
{
"jobId": "04a0dcb0-daa2-4a2e-8195-fac138925c19" // The ID of the job in which these files are being processed.
}
GET /convert/download/:jobId
Get converted files from a job.
Response
- A data stream that should be saved as a ".zip" file.
GET /jobs
Get all jobs that are currently running.
Example Response
{
"jobs": [] // An array of the current running jobs.
}
DELETE /jobs
Delete all jobs that are finished, and the temporary files associated with them.
Note: Jobs are deleted automatically after download, unless the FileConverter
constructor's configuration clearJobOnDownload
value is set to false
.
GET /jobs/:jobId
Get a jobs that is currently running by its ID.
Example Response
{
"job": {} // An object of the found job.
}
DELETE /jobs/:jobId
Get a finished jobs that is by its ID and delete it and all associated files.
Note: Jobs are deleted automatically after download, unless the FileConverter
constructor's configuration clearJobOnDownload
value is set to false
.
GET /stats
Get file conversion statistics.
Example Response
{
"initialization": 1725337284323, // When this file converter instance was initialized, in number of milliseconds elapsed since the epoch.
"filesConverted": 0, // The number of files that have been converted since the converter was initialized.
"dataConverted": 0 // The total amount of data that has been converted since the converter was initialized, in megabytes.
}