dashboard: integrate Flow, sketch message API (#15713)

* dashboard: minor design change

* dashboard: Flow integration, message API

* dashboard: minor polishes, exclude misspell linter

.gitignore

@@ -35,6 +35,7 @@ profile.cov
 .idea
 
 # dashboard
+/dashboard/assets/flow-typed
 /dashboard/assets/node_modules
 /dashboard/assets/stats.json
 /dashboard/assets/public/bundle.js

dashboard/README.md

@@ -9,10 +9,11 @@ The client's UI uses [React][React] with JSX syntax, which is validated by the [
 
 ### Development and bundling
 
-As the dashboard depends on certain NPM packages (which are not included in the go-ethereum repo), these need to be installed first:
+As the dashboard depends on certain NPM packages (which are not included in the `go-ethereum` repo), these need to be installed first:
 
 ```
 $ (cd dashboard/assets && npm install)
+$ (cd dashboard/assets && ./node_modules/.bin/flow-typed install)
 ```
 
 Normally the dashboard assets are bundled into Geth via `go-bindata` to avoid external dependencies. Rebuilding Geth after each UI modification however is not feasible from a developer perspective. Instead, we can run `webpack` in watch mode to automatically rebundle the UI, and ask `geth` to use external assets to not rely on compiled resources:
@@ -22,13 +23,20 @@ $ (cd dashboard/assets && ./node_modules/.bin/webpack --watch)
 $ geth --dashboard --dashboard.assets=dashboard/assets/public --vmodule=dashboard=5
 ```
 
-To bundle up the final UI into Geth, run `webpack` and `go generate`:
+To bundle up the final UI into Geth, run `go generate`:
 
 ```
-$ (cd dashboard/assets && ./node_modules/.bin/webpack)
 $ go generate ./dashboard
 ```
 
+### Static type checking
+
+Since JavaScript doesn't provide type safety, [Flow][Flow] is used to check types. These are only useful during development, so at the end of the process Babel will strip them.
+
+To take advantage of static type checking, your IDE needs to be prepared for it. In case of [Atom][Atom] a configuration guide can be found [here][Atom config]: Install the [Nuclide][Nuclide] package for Flow support, making sure it installs all of its support packages by enabling `Install Recommended Packages on Startup`, and set the path of the `flow-bin` which were installed previously by `npm`.
+
+For more IDE support install the `linter-eslint` package too, which finds the `.eslintrc` file, and provides real-time linting. Atom warns, that these two packages are incompatible, but they seem to work well together. For third-party library errors and auto-completion [flow-typed][flow-typed] is used.
+
 ### Have fun
 
 [Webpack][Webpack] offers handy tools for visualizing the bundle's dependency tree and space usage.
@@ -44,3 +52,8 @@ $ go generate ./dashboard
 [WA]: http://webpack.github.io/analyse/
 [WV]: http://chrisbateman.github.io/webpack-visualizer/
 [Node.js]: https://nodejs.org/en/
+[Flow]: https://flow.org/
+[Atom]: https://atom.io/
+[Atom config]: https://medium.com/@fastphrase/integrating-flow-into-a-react-project-fbbc2f130eed
+[Nuclide]: https://nuclide.io/docs/quick-start/getting-started/
+[flow-typed]: https://github.com/flowtype/flow-typed

dashboard/assets/.eslintrc

@@ -16,37 +16,68 @@
 
 // React syntax style mostly according to https://github.com/airbnb/javascript/tree/master/react
 {
-  "plugins": [
-    "react"
-  ],
-  "parser": "babel-eslint",
-  "parserOptions": {
-    "ecmaFeatures": {
-      "jsx": true,
-      "modules": true
-    }
-  },
-  "rules": {
-    "react/prefer-es6-class": 2,
-    "react/prefer-stateless-function": 2,
-    "react/jsx-pascal-case": 2,
-    "react/jsx-closing-bracket-location": [1, {"selfClosing": "tag-aligned", "nonEmpty": "tag-aligned"}],
-    "react/jsx-closing-tag-location": 1,
-    "jsx-quotes": ["error", "prefer-double"],
-    "no-multi-spaces": "error",
-    "react/jsx-tag-spacing": 2,
-    "react/jsx-curly-spacing": [2, {"when": "never", "children": true}],
-    "react/jsx-boolean-value": 2,
-    "react/no-string-refs": 2,
-    "react/jsx-wrap-multilines": 2,
-    "react/self-closing-comp": 2,
-    "react/jsx-no-bind": 2,
-    "react/require-render-return": 2,
-    "react/no-is-mounted": 2,
-    "key-spacing": ["error", {"align": {
-      "beforeColon": false,
-      "afterColon": true,
-      "on": "value"
-    }}]
-  }
+    'env': {
+        'browser': true,
+        'node':    true,
+        'es6':     true,
+    },
+    'parser': 'babel-eslint',
+    'parserOptions': {
+        'sourceType':   'module',
+        'ecmaVersion':  6,
+        'ecmaFeatures': {
+            'jsx': true,
+        }
+    },
+    'extends': 'airbnb',
+    'plugins': [
+        'flowtype',
+        'react',
+    ],
+    'rules': {
+        'no-tabs':                'off',
+        'indent':                 ['error', 'tab'],
+        'react/jsx-indent':       ['error', 'tab'],
+        'react/jsx-indent-props': ['error', 'tab'],
+        'react/prefer-stateless-function': 'off',
+
+        // Specifies the maximum length of a line.
+        'max-len': ['warn', 120, 2, {
+            'ignoreUrls':             true,
+            'ignoreComments':         false,
+            'ignoreRegExpLiterals':   true,
+            'ignoreStrings':          true,
+            'ignoreTemplateLiterals': true,
+        }],
+        // Enforces spacing between keys and values in object literal properties.
+        'key-spacing': ['error', {'align': {
+            'beforeColon': false,
+            'afterColon':  true,
+            'on':          'value'
+        }}],
+        // Prohibits padding inside curly braces.
+        'object-curly-spacing': ['error', 'never'],
+        'no-use-before-define': 'off', // messageAPI
+        'default-case': 'off',
+
+        'flowtype/boolean-style':                  ['error', 'boolean'],
+        'flowtype/define-flow-type':               'warn',
+        'flowtype/generic-spacing':                ['error', 'never'],
+        'flowtype/no-primitive-constructor-types': 'error',
+        'flowtype/no-weak-types':                  'error',
+        'flowtype/object-type-delimiter':          ['error', 'comma'],
+        'flowtype/require-valid-file-annotation':  'error',
+        'flowtype/semi':                           ['error', 'always'],
+        'flowtype/space-after-type-colon':         ['error', 'always'],
+        'flowtype/space-before-generic-bracket':   ['error', 'never'],
+        'flowtype/space-before-type-colon':        ['error', 'never'],
+        'flowtype/union-intersection-spacing':     ['error', 'always'],
+        'flowtype/use-flow-type':                  'warn',
+        'flowtype/valid-syntax':                   'warn',
+    },
+    'settings': {
+        'flowtype': {
+            'onlyFilesWithFlowAnnotation': true,
+        }
+    },
 }

dashboard/assets/.flowconfig

+[ignore]
+<PROJECT_ROOT>/node_modules/material-ui/.*\.js\.flow
+
+[libs]
+<PROJECT_ROOT>/flow-typed/
+node_modules/jss/flow-typed
+
+[options]
+include_warnings=true

dashboard/assets/components/Body.jsx

+// @flow
+
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+import React, {Component} from 'react';
+
+import withStyles from 'material-ui/styles/withStyles';
+
+import SideBar from './SideBar';
+import Main from './Main';
+import type {Content} from '../types/content';
+
+// Styles for the Body component.
+const styles = () => ({
+	body: {
+		display: 'flex',
+		width:   '100%',
+		height:  '100%',
+	},
+});
+export type Props = {
+	classes: Object,
+	opened: boolean,
+	changeContent: () => {},
+	active: string,
+	content: Content,
+	shouldUpdate: Object,
+};
+// Body renders the body of the dashboard.
+class Body extends Component<Props> {
+	render() {
+		const {classes} = this.props; // The classes property is injected by withStyles().
+
+		return (
+			<div className={classes.body}>
+				<SideBar
+					opened={this.props.opened}
+					changeContent={this.props.changeContent}
+				/>
+				<Main
+					active={this.props.active}
+					content={this.props.content}
+					shouldUpdate={this.props.shouldUpdate}
+				/>
+			</div>
+		);
+	}
+}
+
+export default withStyles(styles)(Body);

dashboard/assets/components/ChartGrid.jsx

+// @flow
+
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+import React, {Component} from 'react';
+import type {Node} from 'react';
+
+import Grid from 'material-ui/Grid';
+import {ResponsiveContainer} from 'recharts';
+
+export type Props = {
+	spacing: number,
+	children: Node,
+};
+// ChartGrid renders a grid container for responsive charts.
+// The children are Recharts components extended with the Material-UI's xs property.
+class ChartGrid extends Component<Props> {
+	render() {
+		return (
+			<Grid container spacing={this.props.spacing}>
+				{
+					React.Children.map(this.props.children, child => (
+						<Grid item xs={child.props.xs}>
+							<ResponsiveContainer width="100%" height={child.props.height}>
+								{React.cloneElement(child, {data: child.props.values.map(value => ({value}))})}
+							</ResponsiveContainer>
+						</Grid>
+					))
+				}
+			</Grid>
+		);
+	}
+}
+
+export default ChartGrid;

dashboard/assets/components/Common.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -14,39 +16,78 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-// isNullOrUndefined returns true if the given variable is null or undefined.
-export const isNullOrUndefined = variable => variable === null || typeof variable === 'undefined';
-
-export const LIMIT = {
-    memory:  200, // Maximum number of memory data samples.
-    traffic: 200, // Maximum number of traffic data samples.
-    log:     200, // Maximum number of logs.
-};
+type ProvidedMenuProp = {|title: string, icon: string|};
+const menuSkeletons: Array<{|id: string, menu: ProvidedMenuProp|}> = [
+	{
+		id:   'home',
+		menu: {
+			title: 'Home',
+			icon:  'home',
+		},
+	}, {
+		id:   'chain',
+		menu: {
+			title: 'Chain',
+			icon:  'link',
+		},
+	}, {
+		id:   'txpool',
+		menu: {
+			title: 'TxPool',
+			icon:  'credit-card',
+		},
+	}, {
+		id:   'network',
+		menu: {
+			title: 'Network',
+			icon:  'globe',
+		},
+	}, {
+		id:   'system',
+		menu: {
+			title: 'System',
+			icon:  'tachometer',
+		},
+	}, {
+		id:   'logs',
+		menu: {
+			title: 'Logs',
+			icon:  'list',
+		},
+	},
+];
+export type MenuProp = {|...ProvidedMenuProp, id: string|};
 // The sidebar menu and the main content are rendered based on these elements.
-export const TAGS = (() => {
-    const T = {
-        home:         { title: "Home", },
-        chain:        { title: "Chain", },
-        transactions: { title: "Transactions", },
-        network:      { title: "Network", },
-        system:       { title: "System", },
-        logs:         { title: "Logs", },
-    };
-    // Using the key is circumstantial in some cases, so it is better to insert it also as a value.
-    // This way the mistyping is prevented.
-    for(let key in T) {
-        T[key]['id'] = key;
-    }
-    return T;
-})();
+// Using the id is circumstantial in some cases, so it is better to insert it also as a value.
+// This way the mistyping is prevented.
+export const MENU: Map<string, {...MenuProp}> = new Map(menuSkeletons.map(({id, menu}) => ([id, {id, ...menu}])));
+
+type ProvidedSampleProp = {|limit: number|};
+const sampleSkeletons: Array<{|id: string, sample: ProvidedSampleProp|}> = [
+	{
+		id:     'memory',
+		sample: {
+			limit: 200,
+		},
+	}, {
+		id:     'traffic',
+		sample: {
+			limit: 200,
+		},
+	}, {
+		id:     'logs',
+		sample: {
+			limit: 200,
+		},
+	},
+];
+export type SampleProp = {|...ProvidedSampleProp, id: string|};
+export const SAMPLE: Map<string, {...SampleProp}> = new Map(sampleSkeletons.map(({id, sample}) => ([id, {id, ...sample}])));
 
-export const DATA_KEYS = (() => {
-    const DK = {};
-    ["memory", "traffic", "logs"].map(key => {
-       DK[key] = key;
-    });
-    return DK;
-})();
+export const DURATION = 200;
 
-// Temporary - taken from Material-UI
-export const DRAWER_WIDTH = 240;
+export const LENS: Map<string, string> = new Map([
+	'content',
+	...menuSkeletons.map(({id}) => id),
+	...sampleSkeletons.map(({id}) => id),
+].map(lens => [lens, lens]));

dashboard/assets/components/Header.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -15,73 +17,89 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 import React, {Component} from 'react';
-import PropTypes from 'prop-types';
-import classNames from 'classnames';
-import {withStyles} from 'material-ui/styles';
+
+import withStyles from 'material-ui/styles/withStyles';
 import AppBar from 'material-ui/AppBar';
 import Toolbar from 'material-ui/Toolbar';
-import Typography from 'material-ui/Typography';
+import Transition from 'react-transition-group/Transition';
 import IconButton from 'material-ui/IconButton';
-import MenuIcon from 'material-ui-icons/Menu';
+import Typography from 'material-ui/Typography';
+import ChevronLeftIcon from 'material-ui-icons/ChevronLeft';
 
-import {DRAWER_WIDTH} from './Common.jsx';
+import {DURATION} from './Common';
 
+// arrowDefault is the default style of the arrow button.
+const arrowDefault = {
+	transition: `transform ${DURATION}ms`,
+};
+// arrowTransition is the additional style of the arrow button corresponding to the transition's state.
+const arrowTransition = {
+	entered: {transform: 'rotate(180deg)'},
+};
 // Styles for the Header component.
 const styles = theme => ({
-    appBar: {
-        position:   'absolute',
-        transition: theme.transitions.create(['margin', 'width'], {
-            easing:   theme.transitions.easing.sharp,
-            duration: theme.transitions.duration.leavingScreen,
-        }),
-    },
-    appBarShift: {
-        marginLeft: DRAWER_WIDTH,
-        width:      `calc(100% - ${DRAWER_WIDTH}px)`,
-        transition: theme.transitions.create(['margin', 'width'], {
-            easing:   theme.transitions.easing.easeOut,
-            duration: theme.transitions.duration.enteringScreen,
-        }),
-    },
-    menuButton: {
-        marginLeft:  12,
-        marginRight: 20,
-    },
-    hide: {
-        display: 'none',
-    },
+	header: {
+		backgroundColor: theme.palette.background.appBar,
+		color:           theme.palette.getContrastText(theme.palette.background.appBar),
+		zIndex:          theme.zIndex.appBar,
+	},
+	toolbar: {
+		paddingLeft:  theme.spacing.unit,
+		paddingRight: theme.spacing.unit,
+	},
+	mainText: {
+		paddingLeft: theme.spacing.unit,
+	},
 });
+export type Props = {
+	classes: Object,
+	opened: boolean,
+	openSideBar: () => {},
+	closeSideBar: () => {},
+};
+// Header renders the header of the dashboard.
+class Header extends Component<Props> {
+	shouldComponentUpdate(nextProps) {
+		return nextProps.opened !== this.props.opened;
+	}
 
-// Header renders a header, which contains a sidebar opener icon when that is closed.
-class Header extends Component {
-    render() {
-        // The classes property is injected by withStyles().
-        const {classes} = this.props;
+	// changeSideBar opens or closes the sidebar corresponding to the previous state.
+	changeSideBar = () => {
+		if (this.props.opened) {
+			this.props.closeSideBar();
+		} else {
+			this.props.openSideBar();
+		}
+	};
 
-        return (
-            <AppBar className={classNames(classes.appBar, this.props.opened && classes.appBarShift)}>
-                <Toolbar disableGutters={!this.props.opened}>
-                    <IconButton
-                        color="contrast"
-                        aria-label="open drawer"
-                        onClick={this.props.open}
-                        className={classNames(classes.menuButton, this.props.opened && classes.hide)}
-                    >
-                        <MenuIcon />
-                    </IconButton>
-                    <Typography type="title" color="inherit" noWrap>
-                        Go Ethereum Dashboard
-                    </Typography>
-                </Toolbar>
-            </AppBar>
-        );
-    }
-}
+	// arrowButton is connected to the sidebar; changes its state.
+	arrowButton = (transitionState: string) => (
+		<IconButton onClick={this.changeSideBar}>
+			<ChevronLeftIcon
+				style={{
+					...arrowDefault,
+					...arrowTransition[transitionState],
+				}}
+			/>
+		</IconButton>
+	);
 
-Header.propTypes = {
-    classes: PropTypes.object.isRequired,
-    opened:  PropTypes.bool.isRequired,
-    open:    PropTypes.func.isRequired,
-};
+	render() {
+		const {classes, opened} = this.props; // The classes property is injected by withStyles().
+
+		return (
+			<AppBar position="static" className={classes.header}>
+				<Toolbar className={classes.toolbar}>
+					<Transition mountOnEnter in={opened} timeout={{enter: DURATION}}>
+						{this.arrowButton}
+					</Transition>
+					<Typography type="title" color="inherit" noWrap className={classes.mainText}>
+						Go Ethereum Dashboard
+					</Typography>
+				</Toolbar>
+			</AppBar>
+		);
+	}
+}
 
 export default withStyles(styles)(Header);

dashboard/assets/components/Home.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -15,75 +17,56 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 import React, {Component} from 'react';
-import PropTypes from 'prop-types';
-import Grid from 'material-ui/Grid';
-import {LineChart, AreaChart, Area, YAxis, CartesianGrid, Line, ResponsiveContainer} from 'recharts';
-import {withTheme} from 'material-ui/styles';
 
-import {isNullOrUndefined, DATA_KEYS} from "./Common.jsx";
+import withTheme from 'material-ui/styles/withTheme';
+import {LineChart, AreaChart, Area, YAxis, CartesianGrid, Line} from 'recharts';
 
-// ChartGrid renders a grid container for responsive charts.
-// The children are Recharts components extended with the Material-UI's xs property.
-class ChartGrid extends Component {
-    render() {
-        return (
-            <Grid container spacing={this.props.spacing}>
-                {
-                    React.Children.map(this.props.children, child => (
-                        <Grid item xs={child.props.xs}>
-                            <ResponsiveContainer width="100%" height={child.props.height}>
-                                {React.cloneElement(child, {data: child.props.values.map(value => ({value: value}))})}
-                            </ResponsiveContainer>
-                        </Grid>
-                    ))
-                }
-            </Grid>
-        );
-    }
-}
+import ChartGrid from './ChartGrid';
+import type {ChartEntry} from '../types/message';
 
-ChartGrid.propTypes = {
-    spacing: PropTypes.number.isRequired,
+export type Props = {
+    theme: Object,
+    memory: Array<ChartEntry>,
+    traffic: Array<ChartEntry>,
+    shouldUpdate: Object,
 };
+// Home renders the home content.
+class Home extends Component<Props> {
+	constructor(props: Props) {
+		super(props);
+		const {theme} = props; // The theme property is injected by withTheme().
+		this.memoryColor = theme.palette.primary[300];
+		this.trafficColor = theme.palette.secondary[300];
+	}
 
-// Home renders the home component.
-class Home extends Component {
-    shouldComponentUpdate(nextProps) {
-        return !isNullOrUndefined(nextProps.shouldUpdate[DATA_KEYS.memory]) ||
-            !isNullOrUndefined(nextProps.shouldUpdate[DATA_KEYS.traffic]);
-    }
+	shouldComponentUpdate(nextProps) {
+		return nextProps.shouldUpdate.has('memory') || nextProps.shouldUpdate.has('traffic');
+	}
 
-    render() {
-        const {theme} = this.props;
-        const memoryColor = theme.palette.primary[300];
-        const trafficColor = theme.palette.secondary[300];
+	render() {
+		const {memory, traffic} = this.props;
 
-        return (
-            <ChartGrid spacing={24}>
-                <AreaChart xs={6} height={300} values={this.props.memory}>
-                    <YAxis />
-                    <Area type="monotone" dataKey="value" stroke={memoryColor} fill={memoryColor} />
-                </AreaChart>
-                <LineChart xs={6} height={300} values={this.props.traffic}>
-                    <Line type="monotone" dataKey="value" stroke={trafficColor} dot={false} />
-                </LineChart>
-                <LineChart xs={6} height={300} values={this.props.memory}>
-                    <YAxis />
-                    <CartesianGrid stroke="#eee" strokeDasharray="5 5" />
-                    <Line type="monotone" dataKey="value" stroke={memoryColor} dot={false} />
-                </LineChart>
-                <AreaChart xs={6} height={300} values={this.props.traffic}>
-                    <CartesianGrid stroke="#eee" strokeDasharray="5 5" vertical={false} />
-                    <Area type="monotone" dataKey="value" stroke={trafficColor} fill={trafficColor} />
-                </AreaChart>
-            </ChartGrid>
-        );
-    }
+		return (
+			<ChartGrid spacing={24}>
+				<AreaChart xs={6} height={300} values={memory}>
+					<YAxis />
+					<Area type="monotone" dataKey="value" stroke={this.memoryColor} fill={this.memoryColor} />
+				</AreaChart>
+				<LineChart xs={6} height={300} values={traffic}>
+					<Line type="monotone" dataKey="value" stroke={this.trafficColor} dot={false} />
+				</LineChart>
+				<LineChart xs={6} height={300} values={memory}>
+					<YAxis />
+					<CartesianGrid stroke="#eee" strokeDasharray="5 5" />
+					<Line type="monotone" dataKey="value" stroke={this.memoryColor} dot={false} />
+				</LineChart>
+				<AreaChart xs={6} height={300} values={traffic}>
+					<CartesianGrid stroke="#eee" strokeDasharray="5 5" vertical={false} />
+					<Area type="monotone" dataKey="value" stroke={this.trafficColor} fill={this.trafficColor} />
+				</AreaChart>
+			</ChartGrid>
+		);
+	}
 }
 
-Home.propTypes = {
-    theme:        PropTypes.object.isRequired,
-    shouldUpdate: PropTypes.object.isRequired,
-};
-
 export default withTheme()(Home);

dashboard/assets/components/Main.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -15,95 +17,52 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 import React, {Component} from 'react';
-import PropTypes from 'prop-types';
-import classNames from 'classnames';
-import {withStyles} from 'material-ui/styles';
-
-import {TAGS, DRAWER_WIDTH} from "./Common.jsx";
-import Home from './Home.jsx';
 
-// ContentSwitch chooses and renders the proper page content.
-class ContentSwitch extends Component {
-    render() {
-        switch(this.props.active) {
-            case TAGS.home.id:
-                return <Home memory={this.props.memory} traffic={this.props.traffic} shouldUpdate={this.props.shouldUpdate} />;
-            case TAGS.chain.id:
-                return null;
-            case TAGS.transactions.id:
-                return null;
-            case TAGS.network.id:
-                // Only for testing.
-                return null;
-            case TAGS.system.id:
-                return null;
-            case TAGS.logs.id:
-                return <div>{this.props.logs.map((log, index) => <div key={index}>{log}</div>)}</div>;
-        }
-        return null;
-    }
-}
+import withStyles from 'material-ui/styles/withStyles';
 
-ContentSwitch.propTypes = {
-    active:       PropTypes.string.isRequired,
-    shouldUpdate: PropTypes.object.isRequired,
-};
+import Home from './Home';
+import {MENU} from './Common';
+import type {Content} from '../types/content';
 
-// styles contains the styles for the Main component.
+// Styles for the Content component.
 const styles = theme => ({
-    content: {
-        width:           '100%',
-        marginLeft:      -DRAWER_WIDTH,
-        flexGrow:        1,
-        backgroundColor: theme.palette.background.default,
-        padding:         theme.spacing.unit * 3,
-        transition:      theme.transitions.create('margin', {
-            easing:   theme.transitions.easing.sharp,
-            duration: theme.transitions.duration.leavingScreen,
-        }),
-        marginTop:                    56,
-        overflow:                     'auto',
-        [theme.breakpoints.up('sm')]: {
-            content: {
-                height:    'calc(100% - 64px)',
-                marginTop: 64,
-            },
-        },
-    },
-    contentShift: {
-        marginLeft: 0,
-        transition: theme.transitions.create('margin', {
-            easing:   theme.transitions.easing.easeOut,
-            duration: theme.transitions.duration.enteringScreen,
-        }),
-    },
+	content: {
+		flexGrow:        1,
+		backgroundColor: theme.palette.background.default,
+		padding:         theme.spacing.unit * 3,
+		overflow:        'auto',
+	},
 });
+export type Props = {
+	classes: Object,
+	active: string,
+	content: Content,
+	shouldUpdate: Object,
+};
+// Main renders the chosen content.
+class Main extends Component<Props> {
+	render() {
+		const {
+			classes, active, content, shouldUpdate,
+		} = this.props;
 
-// Main renders a component for the page content.
-class Main extends Component {
-    render() {
-        // The classes property is injected by withStyles().
-        const {classes} = this.props;
+		let children = null;
+		switch (active) {
+		case MENU.get('home').id:
+			children = <Home memory={content.home.memory} traffic={content.home.traffic} shouldUpdate={shouldUpdate} />;
+			break;
+		case MENU.get('chain').id:
+		case MENU.get('txpool').id:
+		case MENU.get('network').id:
+		case MENU.get('system').id:
+			children = <div>Work in progress.</div>;
+			break;
+		case MENU.get('logs').id:
+			children = <div>{content.logs.log.map((log, index) => <div key={index}>{log}</div>)}</div>;
+		}
 
-        return (
-            <main className={classNames(classes.content, this.props.opened && classes.contentShift)}>
-                <ContentSwitch
-                    active={this.props.active}
-                    memory={this.props.memory}
-                    traffic={this.props.traffic}
-                    logs={this.props.logs}
-                    shouldUpdate={this.props.shouldUpdate}
-                />
-            </main>
-        );
-    }
+		return <div className={classes.content}>{children}</div>;
+	}
 }
 
-Main.propTypes = {
-    classes:      PropTypes.object.isRequired,
-    opened:       PropTypes.bool.isRequired,
-    active:       PropTypes.string.isRequired,
-    shouldUpdate: PropTypes.object.isRequired,
-};
-
 export default withStyles(styles)(Main);

dashboard/assets/components/SideBar.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -15,92 +17,106 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 import React, {Component} from 'react';
-import PropTypes from 'prop-types';
-import {withStyles} from 'material-ui/styles';
-import Drawer from 'material-ui/Drawer';
-import {IconButton} from "material-ui";
-import List, {ListItem, ListItemText} from 'material-ui/List';
-import ChevronLeftIcon from 'material-ui-icons/ChevronLeft';
 
-import {TAGS, DRAWER_WIDTH} from './Common.jsx';
+import withStyles from 'material-ui/styles/withStyles';
+import List, {ListItem, ListItemIcon, ListItemText} from 'material-ui/List';
+import Icon from 'material-ui/Icon';
+import Transition from 'react-transition-group/Transition';
+import {Icon as FontAwesome} from 'react-fa';
+
+import {MENU, DURATION} from './Common';
 
+// menuDefault is the default style of the menu.
+const menuDefault = {
+	transition: `margin-left ${DURATION}ms`,
+};
+// menuTransition is the additional style of the menu corresponding to the transition's state.
+const menuTransition = {
+	entered: {marginLeft: -200},
+};
 // Styles for the SideBar component.
 const styles = theme => ({
-    drawerPaper: {
-        position: 'relative',
-        height:   '100%',
-        width:    DRAWER_WIDTH,
-    },
-    drawerHeader: {
-        display:            'flex',
-        alignItems:         'center',
-        justifyContent:     'flex-end',
-        padding:            '0 8px',
-        ...theme.mixins.toolbar,
-        transitionDuration: {
-            enter: theme.transitions.duration.enteringScreen,
-            exit:  theme.transitions.duration.leavingScreen,
-        }
-    },
+	list: {
+		background: theme.palette.background.appBar,
+	},
+	listItem: {
+		minWidth: theme.spacing.unit * 3,
+	},
+	icon: {
+		fontSize: theme.spacing.unit * 3,
+	},
 });
+export type Props = {
+	classes: Object,
+	opened: boolean,
+	changeContent: () => {},
+};
+// SideBar renders the sidebar of the dashboard.
+class SideBar extends Component<Props> {
+	constructor(props) {
+		super(props);
 
-// SideBar renders a sidebar component.
-class SideBar extends Component {
-    constructor(props) {
-        super(props);
+		// clickOn contains onClick event functions for the menu items.
+		// Instantiate only once, and reuse the existing functions to prevent the creation of
+		// new function instances every time the render method is triggered.
+		this.clickOn = {};
+		MENU.forEach((menu) => {
+			this.clickOn[menu.id] = (event) => {
+				event.preventDefault();
+				props.changeContent(menu.id);
+			};
+		});
+	}
 
-        // clickOn contains onClick event functions for the menu items.
-        // Instantiate only once, and reuse the existing functions to prevent the creation of
-        // new function instances every time the render method is triggered.
-        this.clickOn = {};
-        for(let key in TAGS) {
-            const id = TAGS[key].id;
-            this.clickOn[id] = event => {
-                event.preventDefault();
-                console.log(event.target.key);
-                this.props.changeContent(id);
-            };
-        }
-    }
+	shouldComponentUpdate(nextProps) {
+		return nextProps.opened !== this.props.opened;
+	}
 
-    render() {
-        // The classes property is injected by withStyles().
-        const {classes} = this.props;
+	menuItems = (transitionState) => {
+		const {classes} = this.props;
+		const children = [];
+		MENU.forEach((menu) => {
+			children.push(
+				<ListItem button key={menu.id} onClick={this.clickOn[menu.id]} className={classes.listItem}>
+					<ListItemIcon>
+						<Icon className={classes.icon}>
+							<FontAwesome name={menu.icon} />
+						</Icon>
+					</ListItemIcon>
+					<ListItemText
+						primary={menu.title}
+						style={{
+							...menuDefault,
+							...menuTransition[transitionState],
+							padding: 0,
+						}}
+					/>
+				</ListItem>,
+			);
+		});
+		return children;
+	};
 
-        return (
-            <Drawer
-                type="persistent"
-                classes={{paper: classes.drawerPaper,}}
-                open={this.props.opened}
-            >
-                <div>
-                    <div className={classes.drawerHeader}>
-                        <IconButton onClick={this.props.close}>
-                            <ChevronLeftIcon />
-                        </IconButton>
-                    </div>
-                    <List>
-                        {
-                            Object.values(TAGS).map(tag => {
-                                return (
-                                    <ListItem button key={tag.id} onClick={this.clickOn[tag.id]}>
-                                        <ListItemText primary={tag.title} />
-                                    </ListItem>
-                                );
-                            })
-                        }
-                    </List>
-                </div>
-            </Drawer>
-        );
-    }
-}
+	// menu renders the list of the menu items.
+	menu = (transitionState) => {
+		const {classes} = this.props; // The classes property is injected by withStyles().
 
-SideBar.propTypes = {
-    classes:       PropTypes.object.isRequired,
-    opened:        PropTypes.bool.isRequired,
-    close:         PropTypes.func.isRequired,
-    changeContent: PropTypes.func.isRequired,
-};
+		return (
+			<div className={classes.list}>
+				<List>
+					{this.menuItems(transitionState)}
+				</List>
+			</div>
+		);
+	};
+
+	render() {
+		return (
+			<Transition mountOnEnter in={this.props.opened} timeout={{enter: DURATION}}>
+				{this.menu}
+			</Transition>
+		);
+	}
+}
 
 export default withStyles(styles)(SideBar);

dashboard/assets/fa-only-woff-loader.js

+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// fa-only-woff-loader removes the .eot, .ttf, .svg dependencies of the FontAwesome library,
+// because they produce unused extra blobs.
+module.exports = function(content) {
+	return content
+		.replace(/src.*url(?!.*url.*(\.eot)).*(\.eot)[^;]*;/,'')
+		.replace(/url(?!.*url.*(\.eot)).*(\.eot)[^,]*,/,'')
+		.replace(/url(?!.*url.*(\.ttf)).*(\.ttf)[^,]*,/,'')
+		.replace(/,[^,]*url(?!.*url.*(\.svg)).*(\.svg)[^;]*;/,';');
+};

dashboard/assets/index.jsx

+// @flow
+
 // Copyright 2017 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
@@ -15,22 +17,25 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 import React from 'react';
-import {hydrate} from 'react-dom';
-import {createMuiTheme, MuiThemeProvider} from 'material-ui/styles';
+import {render} from 'react-dom';
+
+import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
+import createMuiTheme from 'material-ui/styles/createMuiTheme';
 
-import Dashboard from './components/Dashboard.jsx';
+import Dashboard from './components/Dashboard';
 
-// Theme for the dashboard.
 const theme = createMuiTheme({
     palette: {
         type: 'dark',
     },
 });
-
-// Renders the whole dashboard.
-hydrate(
-    <MuiThemeProvider theme={theme}>
-        <Dashboard />
-    </MuiThemeProvider>,
-    document.getElementById('dashboard')
-);
+const dashboard = document.getElementById('dashboard');
+if (dashboard) {
+    // Renders the whole dashboard.
+    render(
+        <MuiThemeProvider theme={theme}>
+            <Dashboard />
+        </MuiThemeProvider>,
+        dashboard,
+    );
+}

dashboard/assets/package.json

 {
-  "dependencies": {
-    "babel-core": "^6.26.0",
-    "babel-eslint": "^8.0.1",
-    "babel-loader": "^7.1.2",
-    "babel-preset-env": "^1.6.1",
-    "babel-preset-react": "^6.24.1",
-    "babel-preset-stage-0": "^6.24.1",
-    "classnames": "^2.2.5",
-    "eslint": "^4.5.0",
-    "eslint-plugin-react": "^7.4.0",
-    "material-ui": "^1.0.0-beta.18",
-    "material-ui-icons": "^1.0.0-beta.17",
-    "path": "^0.12.7",
-    "prop-types": "^15.6.0",
-    "recharts": "^1.0.0-beta.0",
-    "react": "^16.0.0",
-    "react-dom": "^16.0.0",
-    "url": "^0.11.0",
-    "webpack": "^3.5.5"
-  }
+    "dependencies": {
+        "babel-core": "^6.26.0",
+        "babel-eslint": "^8.0.3",
+        "babel-loader": "^7.1.2",
+        "babel-plugin-transform-class-properties": "^6.24.1",
+        "babel-plugin-transform-decorators-legacy": "^1.3.4",
+        "babel-plugin-transform-flow-strip-types": "^6.22.0",
+        "babel-plugin-transform-runtime": "^6.23.0",
+        "babel-preset-env": "^1.6.1",
+        "babel-preset-react": "^6.24.1",
+        "babel-preset-stage-0": "^6.24.1",
+        "babel-runtime": "^6.26.0",
+        "classnames": "^2.2.5",
+        "css-loader": "^0.28.7",
+        "eslint": "^4.13.1",
+        "eslint-config-airbnb": "^16.1.0",
+        "eslint-loader": "^1.9.0",
+        "eslint-plugin-import": "^2.8.0",
+        "eslint-plugin-jsx-a11y": "^6.0.3",
+        "eslint-plugin-react": "^7.5.1",
+        "eslint-plugin-flowtype": "^2.40.1",
+        "file-loader": "^1.1.6",
+        "flow-bin": "^0.61.0",
+        "flow-bin-loader": "^1.0.2",
+        "flow-typed": "^2.2.3",
+        "material-ui": "^1.0.0-beta.24",
+        "material-ui-icons": "^1.0.0-beta.17",
+        "path": "^0.12.7",
+        "ramda": "^0.25.0",
+        "react": "^16.2.0",
+        "react-dom": "^16.2.0",
+        "react-fa": "^5.0.0",
+        "react-transition-group": "^2.2.1",
+        "recharts": "^1.0.0-beta.6",
+        "style-loader": "^0.19.1",
+        "url": "^0.11.0",
+        "url-loader": "^0.6.2",
+        "webpack": "^3.10.0"
+    }
 }

dashboard/assets/public/dashboard.html

@@ -6,9 +6,15 @@
         <meta name="viewport" content="width=device-width, initial-scale=1">
 
         <title>Go Ethereum Dashboard</title>
-        <link rel="shortcut icon" type="image/ico" href="https://ethereum.org/favicon.ico"/>
-
-        <!-- TODO (kurkomisi): Return to the external libraries to speed up the bundling during development -->
+        <link rel="shortcut icon" type="image/ico" href="https://ethereum.org/favicon.ico" />
+        <style>
+            ::-webkit-scrollbar {
+                width: 16px;
+            }
+            ::-webkit-scrollbar-thumb {
+                background: #212121;
+            }
+        </style>
     </head>
     <body style="height: 100%; margin: 0">
         <div id="dashboard" style="height: 100%"></div>

dashboard/assets/types/content.jsx

+// @flow
+
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+import type {ChartEntry} from './message';
+
+export type Content = {
+    home: Home,
+    chain: Chain,
+    txpool: TxPool,
+    network: Network,
+    system: System,
+    logs: Logs,
+};
+
+export type Home = {
+    memory: Array<ChartEntry>,
+    traffic: Array<ChartEntry>,
+};
+
+export type Chain = {
+    /* TODO (kurkomisi) */
+};
+
+export type TxPool = {
+    /* TODO (kurkomisi) */
+};
+
+export type Network = {
+    /* TODO (kurkomisi) */
+};
+
+export type System = {
+    /* TODO (kurkomisi) */
+};
+
+export type Logs = {
+    log: Array<string>,
+};

dashboard/assets/types/message.jsx

+// @flow
+
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+export type Message = {
+    home?: HomeMessage,
+    chain?: ChainMessage,
+    txpool?: TxPoolMessage,
+    network?: NetworkMessage,
+    system?: SystemMessage,
+    logs?: LogsMessage,
+};
+
+export type HomeMessage = {
+    memory?: Chart,
+    traffic?: Chart,
+};
+
+export type Chart = {
+    history?: Array<ChartEntry>,
+    new?: ChartEntry,
+};
+
+export type ChartEntry = {
+    time: Date,
+    value: number,
+};
+
+export type ChainMessage = {
+    /* TODO (kurkomisi) */
+};
+
+export type TxPoolMessage = {
+    /* TODO (kurkomisi) */
+};
+
+export type NetworkMessage = {
+    /* TODO (kurkomisi) */
+};
+
+export type SystemMessage = {
+    /* TODO (kurkomisi) */
+};
+
+export type LogsMessage = {
+    log: string,
+};

dashboard/assets/webpack.config.js

@@ -14,23 +14,61 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
+const webpack = require('webpack');
 const path = require('path');
 
 module.exports = {
-    entry:  './index.jsx',
-    output: {
-        path:     path.resolve(__dirname, 'public'),
-        filename: 'bundle.js',
-    },
-    module: {
-        loaders: [
-            {
-                test: /\.jsx$/, // regexp for JSX files
-                loader: 'babel-loader', // The babel configuration is in the package.json.
-                query: {
-                    presets: ['env', 'react', 'stage-0']
-                }
-            },
-        ],
-    },
+	resolve: {
+		extensions: ['.js', '.jsx'],
+	},
+	entry:  './index',
+	output: {
+		path:     path.resolve(__dirname, 'public'),
+		filename: 'bundle.js',
+	},
+	plugins: [
+		new webpack.optimize.UglifyJsPlugin({
+			comments: false,
+			mangle:   false,
+			beautify: true,
+		}),
+	],
+	module: {
+		rules: [
+			{
+				test:    /\.jsx$/, // regexp for JSX files
+				exclude: /node_modules/,
+				use:     [ // order: from bottom to top
+					{
+						loader:  'babel-loader',
+						options: {
+							plugins: [ // order: from top to bottom
+								// 'transform-decorators-legacy', // @withStyles, @withTheme
+								'transform-class-properties', // static defaultProps
+								'transform-flow-strip-types',
+							],
+							presets: [ // order: from bottom to top
+								'env',
+								'react',
+								'stage-0',
+							],
+						},
+					},
+					// 'eslint-loader', // show errors not only in the editor, but also in the console
+				],
+			},
+			{
+				test: /font-awesome\.css$/,
+				use:  [
+					'style-loader',
+					'css-loader',
+					path.resolve(__dirname, './fa-only-woff-loader.js'),
+				],
+			},
+			{
+				test: /\.woff2?$/, // font-awesome icons
+				use:  'url-loader',
+			},
+		],
+	},
 };

dashboard/dashboard.go

@@ -16,7 +16,10 @@
 
 package dashboard
 
-//go:generate go-bindata -nometadata -o assets.go -prefix assets -pkg dashboard assets/public/...
+//go:generate ./assets/node_modules/.bin/webpack --config ./assets/webpack.config.js --context ./assets
+//go:generate go-bindata -nometadata -o assets.go -prefix assets -nocompress -pkg dashboard assets/public/...
+//go:generate gofmt -s -w assets.go
+//go:generate sed -i "s#var _public#//nolint:misspell\\n&#" assets.go
 
 import (
 	"fmt"
@@ -40,7 +43,7 @@ const (
 	trafficSampleLimit = 200 // Maximum number of traffic data samples
 )
 
-var nextId uint32 // Next connection id
+var nextID uint32 // Next connection id
 
 // Dashboard contains the dashboard internals.
 type Dashboard struct {
@@ -48,46 +51,30 @@ type Dashboard struct {
 
 	listener net.Listener
 	conns    map[uint32]*client // Currently live websocket connections
-	charts   charts             // The collected data samples to plot
-	lock     sync.RWMutex       // Lock protecting the dashboard's internals
+	charts   *HomeMessage
+	lock     sync.RWMutex // Lock protecting the dashboard's internals
 
 	quit chan chan error // Channel used for graceful exit
 	wg   sync.WaitGroup
 }
 
-// message embraces the data samples of a client message.
-type message struct {
-	History *charts     `json:"history,omitempty"` // Past data samples
-	Memory  *chartEntry `json:"memory,omitempty"`  // One memory sample
-	Traffic *chartEntry `json:"traffic,omitempty"` // One traffic sample
-	Log     string      `json:"log,omitempty"`     // One log
-}
-
 // client represents active websocket connection with a remote browser.
 type client struct {
 	conn   *websocket.Conn // Particular live websocket connection
-	msg    chan message    // Message queue for the update messages
+	msg    chan Message    // Message queue for the update messages
 	logger log.Logger      // Logger for the particular live websocket connection
 }
 
-// charts contains the collected data samples.
-type charts struct {
-	Memory  []*chartEntry `json:"memorySamples,omitempty"`
-	Traffic []*chartEntry `json:"trafficSamples,omitempty"`
-}
-
-// chartEntry represents one data sample
-type chartEntry struct {
-	Time  time.Time `json:"time,omitempty"`
-	Value float64   `json:"value,omitempty"`
-}
-
 // New creates a new dashboard instance with the given configuration.
 func New(config *Config) (*Dashboard, error) {
 	return &Dashboard{
 		conns:  make(map[uint32]*client),
 		config: config,
 		quit:   make(chan chan error),
+		charts: &HomeMessage{
+			Memory:  &Chart{},
+			Traffic: &Chart{},
+		},
 	}, nil
 }
 
@@ -183,13 +170,13 @@ func (db *Dashboard) webHandler(w http.ResponseWriter, r *http.Request) {
 
 // apiHandler handles requests for the dashboard.
 func (db *Dashboard) apiHandler(conn *websocket.Conn) {
-	id := atomic.AddUint32(&nextId, 1)
+	id := atomic.AddUint32(&nextID, 1)
 	client := &client{
 		conn:   conn,
-		msg:    make(chan message, 128),
+		msg:    make(chan Message, 128),
 		logger: log.New("id", id),
 	}
-	done := make(chan struct{}) // Buffered channel as sender may exit early
+	done := make(chan struct{})
 
 	// Start listening for messages to send.
 	db.wg.Add(1)
@@ -210,8 +197,15 @@ func (db *Dashboard) apiHandler(conn *websocket.Conn) {
 		}
 	}()
 	// Send the past data.
-	client.msg <- message{
-		History: &db.charts,
+	client.msg <- Message{
+		Home: &HomeMessage{
+			Memory: &Chart{
+				History: db.charts.Memory.History,
+			},
+			Traffic: &Chart{
+				History: db.charts.Traffic.History,
+			},
+		},
 	}
 	// Start tracking the connection and drop at connection loss.
 	db.lock.Lock()
@@ -245,29 +239,34 @@ func (db *Dashboard) collectData() {
 			inboundTraffic := metrics.DefaultRegistry.Get("p2p/InboundTraffic").(metrics.Meter).Rate1()
 			memoryInUse := metrics.DefaultRegistry.Get("system/memory/inuse").(metrics.Meter).Rate1()
 			now := time.Now()
-			memory := &chartEntry{
+			memory := &ChartEntry{
 				Time:  now,
 				Value: memoryInUse,
 			}
-			traffic := &chartEntry{
+			traffic := &ChartEntry{
 				Time:  now,
 				Value: inboundTraffic,
 			}
-			// Remove the first elements in case the samples' amount exceeds the limit.
 			first := 0
-			if len(db.charts.Memory) == memorySampleLimit {
+			if len(db.charts.Memory.History) == memorySampleLimit {
 				first = 1
 			}
-			db.charts.Memory = append(db.charts.Memory[first:], memory)
+			db.charts.Memory.History = append(db.charts.Memory.History[first:], memory)
 			first = 0
-			if len(db.charts.Traffic) == trafficSampleLimit {
+			if len(db.charts.Traffic.History) == trafficSampleLimit {
 				first = 1
 			}
-			db.charts.Traffic = append(db.charts.Traffic[first:], traffic)
-
-			db.sendToAll(&message{
-				Memory:  memory,
-				Traffic: traffic,
+			db.charts.Traffic.History = append(db.charts.Traffic.History[first:], traffic)
+
+			db.sendToAll(&Message{
+				Home: &HomeMessage{
+					Memory: &Chart{
+						New: memory,
+					},
+					Traffic: &Chart{
+						New: traffic,
+					},
+				},
 			})
 		}
 	}
@@ -277,6 +276,7 @@ func (db *Dashboard) collectData() {
 func (db *Dashboard) collectLogs() {
 	defer db.wg.Done()
 
+	id := 1
 	// TODO (kurkomisi): log collection comes here.
 	for {
 		select {
@@ -284,15 +284,18 @@ func (db *Dashboard) collectLogs() {
 			errc <- nil
 			return
 		case <-time.After(db.config.Refresh / 2):
-			db.sendToAll(&message{
-				Log: "This is a fake log.",
+			db.sendToAll(&Message{
+				Logs: &LogsMessage{
+					Log: fmt.Sprintf("%-4d: This is a fake log.", id),
+				},
 			})
+			id++
 		}
 	}
 }
 
 // sendToAll sends the given message to the active dashboards.
-func (db *Dashboard) sendToAll(msg *message) {
+func (db *Dashboard) sendToAll(msg *Message) {
 	db.lock.Lock()
 	for _, c := range db.conns {
 		select {

dashboard/message.go

+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package dashboard
+
+import "time"
+
+type Message struct {
+	Home    *HomeMessage    `json:"home,omitempty"`
+	Chain   *ChainMessage   `json:"chain,omitempty"`
+	TxPool  *TxPoolMessage  `json:"txpool,omitempty"`
+	Network *NetworkMessage `json:"network,omitempty"`
+	System  *SystemMessage  `json:"system,omitempty"`
+	Logs    *LogsMessage    `json:"logs,omitempty"`
+}
+
+type HomeMessage struct {
+	Memory  *Chart `json:"memory,omitempty"`
+	Traffic *Chart `json:"traffic,omitempty"`
+}
+
+type Chart struct {
+	History []*ChartEntry `json:"history,omitempty"`
+	New     *ChartEntry   `json:"new,omitempty"`
+}
+
+type ChartEntry struct {
+	Time  time.Time `json:"time,omitempty"`
+	Value float64   `json:"value,omitempty"`
+}
+
+type ChainMessage struct {
+	/* TODO (kurkomisi) */
+}
+
+type TxPoolMessage struct {
+	/* TODO (kurkomisi) */
+}
+
+type NetworkMessage struct {
+	/* TODO (kurkomisi) */
+}
+
+type SystemMessage struct {
+	/* TODO (kurkomisi) */
+}
+
+type LogsMessage struct {
+	Log string `json:"log,omitempty"`
+}