用户可以自由更新或删除其 Google 日历活动。如果用户 在创建会议后更新了活动,您的插件可能需要 通过更新会议数据来响应更改。如果您的 第三方会议系统依赖于对活动数据的跟踪 如果在活动更改时未能更新会议,则会显示会议 会导致糟糕的用户体验。
根据 Google 日历活动称为同步。您可以通过以下方式同步事件更改: 创建 Apps 脚本 可安装触发器 指定日历中的活动。很遗憾,触发器 报告哪些事件发生了变化,而您不能将其限制为仅报告 已创建的会议数量而是必须请求一个 自上次同步以来对日历所做的所有更改, 事件列表,并进行相应的更新。
常规同步过程如下:
- 用户首次创建会议时,系统会初始化同步过程。
- 每当用户创建、更新或删除某个日历活动时 触发器在插件项目中执行触发器函数。
- 触发器函数检查自上次触发、 并确定是否需要更新相关联的第三方 会议
- 任何必要的更新都会通过将第三方分配给会议 API 请求。
- 系统存储了新的同步令牌,因此下一次触发器执行只需 检查日历的最新更改。
初始化同步
当该插件在第三方系统上成功创建会议后, 系统应创建一个可安装的触发器 可响应 事件更改 。
创建触发器后,应通过创建初始 同步令牌。具体方法是直接执行触发器函数。
创建日历触发器
如要进行同步,您的插件需要检测包含附加
会议已更改。这是通过创建一个 EventUpdated
来实现的。
可安装触发器。您的插件
每个日历只需要一个触发器,并且可以以编程方式创建触发器。
创建触发器的理想时机是在用户创建第一场会议、 因为这时候用户就开始使用相应插件了更新后 创建会议 并确认没有错误,您的插件应检查 已存在此触发器,如果未创建该触发器。
实现同步触发器函数
当 Apps 脚本检测到导致以下错误的条件时,就会执行触发器函数:
要触发的触发器。
EventUpdated
个日历触发器
在用户创建、修改或删除指定
日历。
您必须实现插件使用的触发器函数。此触发器函数 应执行以下操作:
- 使用
Calendar.Events.list()
syncToken
,用于检索自上次以来发生了更改的事件列表 同步。使用同步令牌可减少插件的事件数量 必须进行检查。如果在没有有效同步令牌的情况下执行触发器函数,则会返回 完全同步。完全同步只是尝试检索所有活动 才能生成新的有效同步 令牌。
- 系统会检查每个修改后的事件,以确定它是否具有 第三方会议
- 如果活动设有会议,则检查该活动以查看更改的内容。 根据更改,相关会议可能会进行修改 。例如,如果活动被删除了,那么插件应该 可能也会删除该会议
- 如需对会议进行任何必要的更改,请通过调用 API 来 第三方系统
- 完成所有必要的更改后,存储由
nextSyncToken
Calendar.Events.list()
方法。此同步令牌位于Calendar.Events.list()
调用返回的结果页面。
更新 Google 日历活动
在某些情况下,您可能要在执行作业时更新 Google 日历活动,
同步。如果您选择执行此操作,请使用适当的
Google 日历高级服务
请求。请务必使用
条件更新
带有 If-Match
标头。这样可以防止您的更改被无意中修改
覆盖用户在其他客户端中进行的并发更改。
示例
以下示例展示了如何设置日历活动的同步 及其相关的会议
/** * Initializes syncing of conference data by creating a sync trigger and * sync token if either does not exist yet. * * @param {String} calendarId The ID of the Google Calendar. */ function initializeSyncing(calendarId) { // Create a syncing trigger if it doesn't exist yet. createSyncTrigger(calendarId); // Perform an event sync to create the initial sync token. syncEvents({'calendarId': calendarId}); } /** * Creates a sync trigger if it does not exist yet. * * @param {String} calendarId The ID of the Google Calendar. */ function createSyncTrigger(calendarId) { // Check to see if the trigger already exists; if does, return. var allTriggers = ScriptApp.getProjectTriggers(); for (var i = 0; i < allTriggers.length; i++) { var trigger = allTriggers[i]; if (trigger.getTriggerSourceId() == calendarId) { return; } } // Trigger does not exist, so create it. The trigger calls the // 'syncEvents()' trigger function when it fires. var trigger = ScriptApp.newTrigger('syncEvents') .forUserCalendar(calendarId) .onEventUpdated() .create(); } /** * Sync events for the given calendar; this is the syncing trigger * function. If a sync token already exists, this retrieves all events * that have been modified since the last sync, then checks each to see * if an associated conference needs to be updated and makes any required * changes. If the sync token does not exist or is invalid, this * retrieves future events modified in the last 24 hours instead. In * either case, a new sync token is created and stored. * * @param {Object} e If called by a event updated trigger, this object * contains the Google Calendar ID, authorization mode, and * calling trigger ID. Only the calendar ID is actually used here, * however. */ function syncEvents(e) { var calendarId = e.calendarId; var properties = PropertiesService.getUserProperties(); var syncToken = properties.getProperty('syncToken'); var options; if (syncToken) { // There's an existing sync token, so configure the following event // retrieval request to only get events that have been modified // since the last sync. options = { syncToken: syncToken }; } else { // No sync token, so configure to do a 'full' sync instead. In this // example only recently updated events are retrieved in a full sync. // A larger time window can be examined during a full sync, but this // slows down the script execution. Consider the trade-offs while // designing your add-on. var now = new Date(); var yesterday = new Date(); yesterday.setDate(now.getDate() - 1); options = { timeMin: now.toISOString(), // Events that start after now... updatedMin: yesterday.toISOString(), // ...and were modified recently maxResults: 50, // Max. number of results per page of responses orderBy: 'updated' } } // Examine the list of updated events since last sync (or all events // modified after yesterday if the sync token is missing or invalid), and // update any associated conferences as required. var events; var pageToken; do { try { options.pageToken = pageToken; events = Calendar.Events.list(calendarId, options); } catch (err) { // Check to see if the sync token was invalidated by the server; // if so, perform a full sync instead. if (err.message === "Sync token is no longer valid, a full sync is required.") { properties.deleteProperty('syncToken'); syncEvents(e); return; } else { throw new Error(err.message); } } // Read through the list of returned events looking for conferences // to update. if (events.items && events.items.length > 0) { for (var i = 0; i < events.items.length; i++) { var calEvent = events.items[i]; // Check to see if there is a record of this event has a // conference that needs updating. if (eventHasConference(calEvent)) { updateConference(calEvent, calEvent.conferenceData.conferenceId); } } } pageToken = events.nextPageToken; } while (pageToken); // Record the new sync token. if (events.nextSyncToken) { properties.setProperty('syncToken', events.nextSyncToken); } } /** * Returns true if the specified event has an associated conference * of the type managed by this add-on; retuns false otherwise. * * @param {Object} calEvent The Google Calendar event object, as defined by * the Calendar API. * @return {boolean} */ function eventHasConference(calEvent) { var name = calEvent.conferenceData.conferenceSolution.name || null; // This version checks if the conference data solution name matches the // one of the solution names used by the add-on. Alternatively you could // check the solution's entry point URIs or other solution-specific // information. if (name) { if (name === "My Web Conference" || name === "My Recorded Web Conference") { return true; } } return false; } /** * Update a conference based on new Google Calendar event information. * The exact implementation of this function is highly dependant on the * details of the third-party conferencing system, so only a rough outline * is shown here. * * @param {Object} calEvent The Google Calendar event object, as defined by * the Calendar API. * @param {String} conferenceId The ID used to identify the conference on * the third-party conferencing system. */ function updateConference(calEvent, conferenceId) { // Check edge case: the event was cancelled if (calEvent.status === 'cancelled' || eventHasConference(calEvent)) { // Use the third-party API to delete the conference too. } else { // Extract any necessary information from the event object, then // make the appropriate third-party API requests to update the // conference with that information. } }