jsonform/playground/examples/fields-file.json

Client-side JavaScript library that generates HTML forms from structured data models expressed using a JSON schema, possibly completed by a form layout description.

{
  "schema": {
    "file_content":{
      "title":"File content",
      "type":"string"
    },
    "upload":{
      "type":"string"
    }
  },
  "form": [
    {
      "key":"file_content",
      "type":"textarea"
    },
    {
      "key":"upload",
      "type":"file",
      "accept":".txt,.md",
      "notitle":true,
      "onChange": function (evt, node) {
        if (evt.target.files[0]) {
          var reader = new FileReader();
          reader.onload = function(event) {
            document.getElementsByName('file_content')[0].value = event.target.result;
          };
          reader.readAsText(evt.target.files[0]);
        } else {
          document.getElementsByName('file_content')[0].value = '';
        }
      }
    },
    {
      "type": "submit",
      "title": "Submit"
    }
  ]
}