sweetleon

<form method="POST" action="/our/url">
    <!-- this should have the current value of version_number -->
    <input type="hidden" name="version_number" value="1" />
    <textarea name="input" onChange="save(event)" />
</form>


function save(event) {
    event.target.form['version_number'].value++;
    var request = new XMLHttpRequest();

sweetleon

class RecordsController < ApplicationController
    def update
        # TODO: remove the line below when the testing is complete
        sleep(1) if 0 == params[:input].length % 2
        @record = Record.find(params[:id])
        @record.update(field_name: params[:input]) if params[:version_number] > @record.version_number
    end
end

sweetleon

class RecordsController < ApplicationController
    def update
        # TODO: remove the line below when the testing is complete
        sleep(1) if 0 == params[:input].length % 2
        @record = Record.find(params[:id])
        @record.update(field_name: params[:input])
    end
end

sweetleon

<form method="POST" action="/our/url">
    <textarea name="input" onChange="save(event)" />
</form>

<script language="javascript">
function save(event) {
    var request = new XMLHttpRequest();
    request.open(event.target.form.method, event.target.form.action);
    request.send(new FormData(event.target.form));
}