Name should not be required for properties in data-url format

[nouman91]

Prerequisites

• [ Yes] I have read the documentation;
• [Yes ] In the case of a bug report, I understand that providing a SSCCE example is tremendously useful to the maintainers.

Description

[Thank you for this awesome library. I have been using it extensively. Our primary work for this library to build ui dynamically through custom widgets using materil-ui and some others. Recently I created a custom file upload widget using https://github.com/react-dropzone/react-dropzone As I was going through documentation it says file widget only supports data-url. So i got bit worried how i will get to know file name since data-url does not contain file name. So I decided to skip name entirely continued my work. After completing file upload widget when I tested it, it kept on giving me this error file is not of type data-uri. Here is how I was setting its value
handleOnDropAccepeted(file){
let uploadedFilesNames = [];

    let reader = new FileReader();
    reader.readAsDataURL(file[0]);
    reader.onloadend = () => {
        this.props.onChange(reader.result);
    }
}

It boggled me for hours as I could not figure out why it is not working. Then upon looking into your code I saw you are also encoding file name there in base64 and if we did not encode file name in string it will complain saying string data is not valid data-uri. So please mention this in your documentation for custom file upload widget you also need to encode file name there as well. Here is how my code looks now
export const addNameToDataURI=(dataURL, name)=>{
return dataURL.replace(";base64", ;name=${name};base64);
}

handleOnDropAccepeted(file){
let uploadedFilesNames = [];

    let reader = new FileReader();
    reader.readAsDataURL(file[0]);
    reader.onloadend = () => {
        this.props.onChange(addNameToDataURI(reader.result, file[0].name));
    }
}

as you can see encoding name into file is basically function from your code source
]

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Expected behavior

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Actual behavior

[What actually happened]

Version

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[glasserc]

Hi, yes, thanks for the report. I didn't realize we validate that the name field is present for data-url formats. See validate.js. I don't think we should necessarily enforce this and I would be willing to review a PR that makes name optional.