grafana/public/app/plugins/datasource/stackdriver/components/Help.tsx

import React from 'react';
import { Project } from './Project';

export interface Props {
  datasource: any;
  rawQuery: string;
  lastQueryError: string;
}

interface State {
  displayHelp: boolean;
  displaRawQuery: boolean;
}

export class Help extends React.Component<Props, State> {
  state: State = {
    displayHelp: false,
    displaRawQuery: false,
  };

  handleHelpClicked() {
    this.setState({ displayHelp: !this.state.displayHelp });
  }

  handleRawQueryClicked() {
    this.setState({ displaRawQuery: !this.state.displaRawQuery });
  }

  shouldComponentUpdate(nextProps) {
    return nextProps.metricDescriptor !== null;
  }

  render() {
    const { displayHelp, displaRawQuery } = this.state;
    const { datasource, rawQuery, lastQueryError } = this.props;

    return (
      <>
        <div className="gf-form-inline">
          <Project datasource={datasource} />
          <div className="gf-form" onClick={() => this.handleHelpClicked()}>
            <label className="gf-form-label query-keyword">
              Show Help
              <i className={`fa fa-caret-${displayHelp ? 'down' : 'right'}`} />
            </label>
          </div>

          {rawQuery && (
            <div className="gf-form" onClick={() => this.handleRawQueryClicked()}>
              <label className="gf-form-label query-keyword">
                Raw Query
                <i className={`fa fa-caret-${displaRawQuery ? 'down' : 'right'}`} ng-show="ctrl.showHelp" />
              </label>
            </div>
          )}

          <div className="gf-form gf-form--grow">
            <div className="gf-form-label gf-form-label--grow" />
          </div>
        </div>
        {rawQuery &&
          displaRawQuery && (
            <div className="gf-form">
              <pre className="gf-form-pre">{rawQuery}</pre>
            </div>
          )}

        {displayHelp && (
          <div className="gf-form grafana-info-box" style={{ padding: 0 }}>
            <pre className="gf-form-pre alert alert-info" style={{ marginRight: 0 }}>
              <h5>Alias Patterns</h5>Format the legend keys any way you want by using alias patterns. Format the legend
              keys any way you want by using alias patterns.<br /> <br />
              Example:
              <code>{`${'{{metricDescriptor.name}} - {{metricDescriptor.label.instance_name}}'}`}</code>
              <br />
              Result: &nbsp;&nbsp;<code>cpu/usage_time - server1-europe-west-1</code>
              <br />
              <br />
              <strong>Patterns</strong>
              <br />
              <ul>
                <li>
                  <code>{`${'{{metricDescriptor.type}}'}`}</code> = metric type e.g.
                  compute.googleapis.com/instance/cpu/usage_time
                </li>
                <li>
                  <code>{`${'{{metricDescriptor.name}}'}`}</code> = name part of metric e.g. instance/cpu/usage_time
                </li>
                <li>
                  <code>{`${'{{metricDescriptor.service}}'}`}</code> = service part of metric e.g. compute
                </li>
                <li>
                  <code>{`${'{{metricDescriptor.label.label_name}}'}`}</code> = Metric label metadata e.g.
                  metricDescriptor.label.instance_name
                </li>
                <li>
                  <code>{`${'{{resource.label.label_name}}'}`}</code> = Resource label metadata e.g. resource.label.zone
                </li>
              </ul>
            </pre>
          </div>
        )}

        {lastQueryError && (
          <div className="gf-form">
            <pre className="gf-form-pre alert alert-error">{lastQueryError}</pre>
          </div>
        )}
      </>
    );
  }
}