如何在另一个选择器中调用NGRX选择器（接受要计算的参数）

Question

我创建了两个选择器

1. 以获取所有网络 - 导出const getallnetworks = createSelector（getState，state =＆gt; state.networks）;

2. 获取每个网络的设备

     createSelector（getallnetworks，network =＆gt; {
       const selectionnetwork = network.filter（net =＆gt; net.id ===== networkId）;
       返回selectednetwork [0]？。alldevices;
     }）;
   
    

我想创建一个使用第一个选择器获取网络的第三个选择器，然后使用第二个选择器获取其他数据

export const something = createSelector(
  getAllNetworks, (networks) => {
    networks.map(

      // How can I call the selector selectNetworkDevices by passing the network ID here and get the devices [ex: selectNetworkDevices(network.id)]

    )
  }
)

Answer 1

您可以基于其他类似的选择来使用不同的选择器：

export const selectUsers = createSelector(getState, (state) => state.users);

export const selectAccounts = (accountId?: string) => 
 createSelector(getState, (state) => 
   accountId ? state.accounts[accountId] : {}
 );

export const something = (accountId?: string) => 
  createSelector(
    selectUsers,
    selectAccounts(accountId),
    (usersData, accountsData) => {
      // some logic
      return accountId ? 'an account id was provided' : 'no-id'
    }
  )

在组件中，您可以调用此选择器提供参数是否提供参数：

ngOnInit(): void {
  this.store.select(something());  // without parameter
  this.store.select(something('anAccountId')); // with parameter
}

更多信息在这里： link

更新：

我们有2个 selectors ， selectaccounts 和 Myotherselector 。对于 Myotherselector ，您可以通过调用其回调函数来重复使用 selectAccounts 选择器，而是可以重复使用其逻辑。

export const selectUsers = createSelector(getState, (state) => state.users);

export const selectAccounts = (accountId?: string) => 
 createSelector(getState, (state) => filterAccount(state));

export const myOtherSelector = createSelector(
  selectUsers,
  (users) => {
    if (users) return users;

    // here, you are reusing the callback function related to
    // another selector
    const accountFiltered = filterAccount([]);
    return accountFiltered;
  }
)

function filterAccount(accounts): Account {
 //...some complex logic 
 // ...
 // ...
 return account[index];
}