TypeScript/SPFx Promises throws Exception("Cannot read property 'then' of undefined") 但似乎有效

Question

我尝试创建一个 SPFx Webpart。在创建新项目之前，我需要调用 0-4 次 _ensureUser，这取决于是否设置了 Client、AssignedTo、ResolvedBy 和 Referrer 的任何组合。当所有必需的_ensureUser 调用完成后，就可以创建新项目了。

代码在托管工作台上调试时运行，但在我调用 userPromises[0].then( (value: {}) => { ... 或 Promise.all(userPromises).then( (value: {}[]) => { ... 时抛出异常。当我单击 F5/继续时，将执行其余部分并创建新项目。 _ensureUser 在我直接调用它并将其与 then 链接时起作用，而不是先将其放入 userPromises 数组中。

我认为问题在于，_ensureUser 不会返回 Promise。如果是这样，我该怎么做？我应该重组_ensureUser 和/或createItem 吗？我需要在某处调用 bind 吗？

createItem 函数：

public createItem( logItem: IInteractionLogItem): Promise<IInteractionLogItem[]> {
  const userPromises: Promise<{}>[] = [];

  if(logItem.Client && logItem.Client.AccountName){
    userPromises.push(this._ensureUser(logItem.Client));
  }

  if(logItem.AssignedTo && logItem.AssignedTo.AccountName){
    userPromises.push(this._ensureUser(logItem.AssignedTo));
  }

  if(logItem.ResolvedBy && logItem.ResolvedBy.AccountName){
    userPromises.push(this._ensureUser(logItem.ResolvedBy));
  }

  if(logItem.Referrer && logItem.Referrer.AccountName){
    userPromises.push(this._ensureUser(logItem.Referrer));
  }

  console.log("SharePointDataProvider.CreateItem: userPromises.length=" + userPromises.length);

  if( userPromises.length == 0) {
      const batch: SPHttpClientBatch = this.webPartContext.spHttpClient.beginBatch();

      const batchPromises: Promise<{}>[] = [
        this._createItem(batch, logItem),
        this._getItemsBatched(batch)
      ];

      return this._resolveBatch(batch, batchPromises);
  } else if( userPromises.length == 1) {
    userPromises[0].then( (value: {}) => {
      const batch: SPHttpClientBatch = this.webPartContext.spHttpClient.beginBatch();

      const batchPromises: Promise<{}>[] = [
        this._createItem(batch, logItem),
        this._getItemsBatched(batch)
      ];

      return this._resolveBatch(batch, batchPromises);
    });
  } else {
    Promise.all(userPromises).then( (value: {}[]) => {
      const batch: SPHttpClientBatch = this.webPartContext.spHttpClient.beginBatch();

      const batchPromises: Promise<{}>[] = [
        this._createItem(batch, logItem),
        this._getItemsBatched(batch)
      ];

      return this._resolveBatch(batch, batchPromises);
    });
  }
}

_ensureUser 函数：

private _ensureUser( user: IInteractionLogPerson): Promise<ISPUser> {
  console.log("SharePointDataProvider.EnsureUser( \"" + user.AccountName + "\" )");
  var data = {logonName: user.AccountName};

  return this._webPartContext.spHttpClient.post(
    this._ensureUserUrl, 
    SPHttpClient.configurations.v1,
    { body: JSON.stringify(data) } ).then(
      (value: SPHttpClientResponse) => {
        console.log("SharePointDataProvider.EnsureUser Got Http Response:\"" + value.statusText + "\"" );
        return value.json();
      },
      (error: any) => console.log("SharePointDataProvider.EnsureUser Rejected: " + error )
    ).then((spUser: ISPUser) => {
      console.log("SharePointDataProvider.EnsureUser Set Id:" + spUser.Id +" LoginName:\"" + spUser.LoginName + "\"" );
      user.Id = spUser.Id;
      return spUser;
    });
}

1 个_ensureUser 调用的调试输出：

SharePointDataProvider.EnsureUser( "i:0#.f|membership|bob@pc.org.nz" )
SharePointDataProvider.CreateItem: userPromises.length=1
TypeError: Cannot read property 'then' of undefined
    at ILoggerContainer._createInteractionLogItem (d:\spfx\iLogger-webpart\dist\i-logger.bundle.js:22103:60)
    at ILoggerForm._handleAddButtonClick (d:\spfx\iLogger-webpart\dist\i-logger.bundle.js:23173:21)
    at Object.r (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:75541)
    at a (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:30260)
    at Object.s [as executeDispatchesInOrder] (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:30475)
    at f (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:26933)
    at m (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:27059)
    at Array.forEach (<anonymous>)
    at r (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:112499)
    at Object.processEventQueue (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:28121)
SharePointDataProvider.EnsureUser Got Http Response:"OK"
SharePointDataProvider.EnsureUser Set Id:13 LoginName:"i:0#.f|membership|bob@pc.org.nz"

2 个_ensureUser 调用的调试输出：

SharePointDataProvider.EnsureUser( "i:0#.f|membership|dennis@carehouse.org.nz" )
SharePointDataProvider.EnsureUser( "i:0#.f|membership|bob@pc.org.nz" )
SharePointDataProvider.CreateItem: userPromises.length=2
TypeError: Cannot read property 'then' of undefined
    at ILoggerContainer._createInteractionLogItem (d:\spfx\iLogger-webpart\dist\i-logger.bundle.js:22103:60)
    at ILoggerForm._handleAddButtonClick (d:\spfx\iLogger-webpart\dist\i-logger.bundle.js:23173:21)
    at Object.r (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:75541)
    at a (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:30260)
    at Object.s [as executeDispatchesInOrder] (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:30475)
    at f (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:26933)
    at m (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:27059)
    at Array.forEach (<anonymous>)
    at r (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:112499)
    at Object.processEventQueue (https://spoprod-a.akamaihd.net/files/sp-client-prod_2017-06-30.017/sp-webpart-workbench-assembly_en-us_f3fed222daad2a0117a4c168deed7705.js:174:28121)
SharePointDataProvider.EnsureUser Got Http Response:"OK"
SharePointDataProvider.EnsureUser Set Id:10 LoginName:"i:0#.f|membership|dennis@carehouse.org.nz"
SharePointDataProvider.EnsureUser Got Http Response:"OK"
SharePointDataProvider.EnsureUser Set Id:13 LoginName:"i:0#.f|membership|bob@pc.org.nz"

Answer 1

我需要在调用userPromises[0].then( (value: {}) => { ... 或Promise.all(userPromises).then( (value: {}[]) => { ... 之前添加return。该代码现在可以进行以下修改：

return userPromises[0].then( (value: {}) => {

和

return Promise.all(userPromises).then( (value: {}[]) => {

Answer 2

return ctx.spHttpClient.get(
        url+'/_api/web/lists',
        SPHttpClient.configurations.v1,
        {
            headers: [
                ['accept', 'application/json;odata.metadata=none']
            ]
        }
    ).then((response: SPHttpClientResponse):Promise<ILists> => {
        return response.json();
    });