app.jsx

		render: function () {
			var employees = this.props.employees.map(employee =>
				client({method: 'GET', path: employee._links.self.href}).then(response =>
					<Employee key={response.entity._links.self.href}
							 headers={response.headers}
							 employee={response.entity}
							 attributes={this.props.attributes}
							 onUpdate={this.props.onUpdate}
							 onDelete={this.props.onDelete}/>
				)
			);

			console.log(employees);

			var the_results = when.all(employees).then(results => {
				/* I got results right here */
			});

			var navLinks = [];
			if ("first" in this.props.links) {
				navLinks.push(<button key="first" onClick={this.handleNavFirst}>&lt;&lt;</button>);
			}
			if ("prev" in this.props.links) {
				navLinks.push(<button key="prev" onClick={this.handleNavPrev}>&lt;</button>);
			}
			if ("next" in this.props.links) {
				navLinks.push(<button key="next" onClick={this.handleNavNext}>&gt;</button>);
			}
			if ("last" in this.props.links) {
				navLinks.push(<button key="last" onClick={this.handleNavLast}>&gt;&gt;</button>);
			}

			return (
				<div>
					<input ref="pageSize" defaultValue={this.props.pageSize} onInput={this.handleInput}/>
					<table>
						<tr>
							<th>First Name</th>
							<th>Last Name</th>
							<th>Description</th>
							<th></th>
						</tr>
						{employees}
					</table>
					<div>
						{navLinks}
					</div>
				</div>
			)
		}

You can't expect to be able to "extract" a value synchronously from inside the promise there, since the value might only exist in the future (and there's no blocking in JS). I think the right thing to do is fetch the employees somewhere else (not in render) and cache them. Then, implement render simply to render whatever is cached, or some default view (or empty list of employees) if the employees haven't been fetched at all yet.

Does that make sense?

Ahh. Maybe this.setState({/* fetched data*/}) once the data is fetched would the reactive way to go.