var ApiRequestMixin = function(url, success, error) {
    apiRequestIds: [],

    componentDidMount: function() {
        var requestId = api.request(url, {
            success: success.bind(this),
            error: error.bind(this)
        });

        this.apiRequestIds.push(requestId);
    },

    componentWillUnmount: function() {
        api.cancelRequests(this.apiRequestIds);
    },
}

React.createClass({
    mixins: [
        ApiRequestMixin('http://...',
            function() {
                success...
            },
            function() {
                error...
            }
    ],
});