var ApiRequestMixin = function(url, success, error) {
    return {
        apiRequest: {
            ids: [],
            success: success,
            error: error
        },

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

            this.apiRequest.ids.push(requestId);
        },

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

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