feat(@cockpit/explorer): implement pagination for accounts explorer

Display two accounts per page in the explorer overview. Display ten accounts
per page in the accounts explorer page.

Sort accounts by their api-supplied index numbers with the lowest index coming
first.

Change the `initBlockHeader` saga so that it triggers a re-fetch of accounts
and therefore the "Tx Count" numbers of displayed accounts will reflect
increased counts.

packages/embark-ui/src/components/Accounts.js

@@ -2,17 +2,19 @@ import React from 'react';
 import {Row, Col, Card, CardHeader, CardBody} from 'reactstrap';
 import {Link} from 'react-router-dom';
 import PropTypes from 'prop-types';
+import Pagination from './Pagination';
 
 import CardTitleIdenticon from './CardTitleIdenticon';
 
-const Accounts = ({accounts}) => (
+const Accounts = ({accounts, changePage, currentPage, numberOfPages}) => (
   <Row>
     <Col>
       <Card>
         <CardHeader>
           <h2>Accounts</h2>
         </CardHeader>
         <CardBody>
+          {!accounts.length && "No accounts to display"}
           {accounts.map(account => (
             <div className="explorer-row border-top" key={account.address}>
               <CardTitleIdenticon id={account.address}>Account&nbsp;
@@ -34,14 +36,18 @@ const Accounts = ({accounts}) => (
               </Row>
             </div>
           ))}
+          {numberOfPages > 1 && <Pagination changePage={changePage} currentPage={currentPage} numberOfPages={numberOfPages}/>}
         </CardBody>
       </Card>
     </Col>
   </Row>
 );
 
 Accounts.propTypes = {
-  accounts: PropTypes.arrayOf(PropTypes.object)
+  accounts: PropTypes.arrayOf(PropTypes.object),
+  changePage: PropTypes.func,
+  currentPage: PropTypes.number,
+  numberOfPages: PropTypes.number
 };
 
 export default Accounts;

packages/embark-ui/src/components/ExplorerDashboardLayout.js

@@ -17,7 +17,7 @@ const ExplorerDashboardLayout = () => (
     <div className="explorer-overview">
       <Row>
         <Col>
-          <AccountsContainer overridePageHead={false} />
+          <AccountsContainer numAccountsToDisplay={2} overridePageHead={false} />
         </Col>
       </Row>
       <Row>

packages/embark-ui/src/containers/AccountsContainer.js

@@ -1,37 +1,105 @@
 import React, {Component} from 'react';
 import {connect} from 'react-redux';
 import PropTypes from 'prop-types';
-
-import {accounts as accountsAction} from '../actions';
+import {accounts as accountsAction,
+        initBlockHeader,
+        stopBlockHeader} from '../actions';
 import Accounts from '../components/Accounts';
-import DataWrapper from "../components/DataWrapper";
 import {getAccounts} from "../reducers/selectors";
 import PageHead from "../components/PageHead";
 
+const MAX_ACCOUNTS = 10;
+
 class AccountsContainer extends Component {
+  constructor(props) {
+    super(props);
+
+    this.numAccountsToDisplay = this.props.numAccountsToDisplay || MAX_ACCOUNTS;
+    this.state = {currentPage: 1};
+  }
+
   componentDidMount() {
     this.props.fetchAccounts();
+    this.props.initBlockHeader();
+  }
+
+  componentWillUnmount() {
+    this.props.stopBlockHeader();
+  }
+
+  get numberOfAccounts() {
+    if (this._numberOfAccounts === undefined) {
+      this._numberOfAccounts = this.props.accounts.length;
+    }
+    return this._numberOfAccounts;
+  }
+
+  get numberOfPages() {
+    if (this._numberOfPages === undefined) {
+      this._numberOfPages = Math.ceil(
+        this.numberOfAccounts / this.numAccountsToDisplay
+      );
+    }
+    return this._numberOfPages;
+  }
+
+  resetNums() {
+    this._numberOfAccounts = undefined;
+    this._numberOfPages = undefined;
+  }
+
+  changePage(newPage) {
+    if (newPage <= 0) {
+      newPage = 1;
+    } else if (newPage > this.numberOfPages) {
+      newPage = this.numberOfPages;
+    }
+    this.setState({ currentPage: newPage });
+    this.props.fetchAccounts();
+  }
+
+  get currentAccounts() {
+    return this.props.accounts
+      .filter((account) => {
+        const index = (
+          (account.index + 1) -
+            (this.numAccountsToDisplay * (this.state.currentPage - 1))
+        );
+        return index <= this.numAccountsToDisplay && index > 0;
+      });
   }
 
   render() {
+    this.resetNums();
     return (
       <React.Fragment>
-        <PageHead title="Accounts" enabled={this.props.overridePageHead} description="Summary view of the accounts configured for Embark" />
-        <DataWrapper shouldRender={this.props.accounts.length > 0} {...this.props} render={({accounts}) => (
-          <Accounts accounts={accounts} />
-        )} />
+        <PageHead
+          title="Accounts"
+          enabled={this.props.overridePageHead}
+          description="Summary view of the accounts configured for Embark" />
+        <Accounts accounts={this.currentAccounts}
+                  numberOfPages={this.numberOfPages}
+                  changePage={(newPage) => this.changePage(newPage)}
+                  currentPage={this.state.currentPage} />
       </React.Fragment>
     );
   }
 }
 
 function mapStateToProps(state) {
-  return {accounts: getAccounts(state), error: state.errorMessage, loading: state.loading};
+  return {
+    accounts: getAccounts(state),
+    error: state.errorMessage,
+    loading: state.loading
+  };
 }
 
 AccountsContainer.propTypes = {
   accounts: PropTypes.arrayOf(PropTypes.object),
   fetchAccounts: PropTypes.func,
+  numAccountsToDisplay: PropTypes.number,
+  initBlockHeader: PropTypes.func,
+  stopBlockHeader: PropTypes.func,
   error: PropTypes.string,
   loading: PropTypes.bool,
   overridePageHead: PropTypes.bool
@@ -40,6 +108,8 @@ AccountsContainer.propTypes = {
 export default connect(
   mapStateToProps,
   {
-    fetchAccounts: accountsAction.request
+    fetchAccounts: accountsAction.request,
+    initBlockHeader,
+    stopBlockHeader
   },
 )(AccountsContainer);

packages/embark-ui/src/reducers/index.js

@@ -41,6 +41,9 @@ const entitiesDefaultState = {
 };
 
 const sorter = {
+  accounts: function(a, b) {
+    return a.index - b.index;
+  },
   blocks: function(a, b) {
     return b.number - a.number;
   },

packages/embark-ui/src/sagas/index.js

@@ -420,6 +420,7 @@ export function *initBlockHeader() {
       channel.close();
       return;
     }
+    yield put({type: actions.ACCOUNTS[actions.REQUEST]});
     yield put({type: actions.BLOCKS[actions.REQUEST]});
     yield put({type: actions.BLOCKS_FULL[actions.REQUEST], txObjects: true, txReceipts: true});
     yield put({type: actions.TRANSACTIONS[actions.REQUEST]});