预览链接

为避免用户在 Google Chat 中分享链接时切换上下文，Chat 应用可以预览链接，方法是在用户消息中附加卡片，其中包含更多信息，并允许用户直接在 Google Chat 中采取行动。

例如，假设某个 Google Chat 聊天室包含某公司的所有客服人员，以及一个名为 Case-y 的 Chat 应用。 客服人员经常在聊天室中分享客户服务支持请求的链接，每次分享后，同事都必须打开支持请求链接才能查看受理人、状态和主题等详细信息。同样，如果有人想接手支持请求或更改其状态，则需要打开该链接。

链接预览功能可让聊天室的常驻 Chat 应用 Case-y 在有人分享支持请求链接时附加一张卡片，其中显示分配对象、状态和主题。通过卡片上的按钮，客服人员可以直接从聊天串中接手支持请求并更改其状态。

链接预览功能的运作方式

当用户向消息中添加链接时，系统会显示一个条状标签，告知用户 Chat 应用可能会预览该链接。

发送消息后，链接会发送到 Chat 应用，然后该应用会生成卡片并将其附加到用户的消息中。

除了链接之外，卡片还提供有关该链接的其他信息，包括按钮等互动元素。您的 Chat 应用可以根据用户互动（例如按钮点击）更新附加的卡片。

如果用户不希望 Chat 应用通过在消息中附加卡片来预览其链接，可以点击预览条状标签中的 来阻止预览。用户可以随时点击移除预览来移除附加的卡片。

前提条件

HTTP

一种 Google Chat 应用，可接收并响应用户互动。 如需构建一个，请完成 HTTP 快速入门。

注意：本指南中的代码示例旨在作为 Google Cloud Run 函数在 Node.js 中运行。

Apps 脚本

一种 Google Chat 应用，可接收并响应用户互动。 如需构建一个，请完成 Apps 脚本快速入门。

配置链接预览

在 Google Cloud 控制台的 Chat 应用配置页面上，将特定链接（例如 example.com、support.example.com 和 support.example.com/cases/）注册为网址格式，以便 Chat 应用可以预览这些链接。

1. 打开 Google Cloud 控制台。
2. 点击“Google Cloud”旁边的向下箭头 ，然后打开 Chat 应用的项目。
3. 在搜索字段中，输入 Google Chat API，然后点击 Google Chat API。
4. 依次点击管理 > 配置。
5. 在“链接预览”下方，添加或修改网址格式。
   1. 如需为新的网址格式配置链接预览，请点击添加网址格式。
   2. 如需修改现有网址格式的配置，请点击向下箭头 。

6. 在主机模式字段中，输入网址格式的网域。Chat 应用将预览指向此网域的链接。

   如需让 Chat 应用预览特定子网域（例如 subdomain.example.com）的链接，请添加该子网域。

   如需让 Chat 应用预览整个网域的链接，请指定一个带有星号 (*) 的通配符作为子网域。例如，*.example.com 与 subdomain.example.com 和 any.number.of.subdomains.example.com 匹配。

7. 在路径前缀字段中，输入要附加到主机模式网域的路径。

   如需匹配主机模式网域中的所有网址，请将路径前缀留空。

   例如，如果主机模式为 support.example.com，则要匹配托管在 support.example.com/cases/ 的支持请求网址，请输入 cases/。

8. 点击完成。

9. 点击保存。

现在，每当有人在包含您的 Chat 应用的 Chat 聊天室中，在消息中添加与链接预览网址格式匹配的链接时，您的应用都会预览该链接。

预览链接

为指定链接配置链接预览后，Chat 应用可以通过附加更多信息来识别和预览该链接。

在包含 Chat 应用的聊天室中，当某人的消息包含与链接预览网址格式匹配的链接时，您的 Chat 应用会收到包含 MessagePayload 的事件对象。在载荷中，message.matchedUrl (chat.messagePayload.message.matchedUrl.url) 对象包含用户在消息中添加的链接：

JSON

message: {
  matchedUrl: {
    url: "https://support.example.com/cases/case123"
  },
  ... // other message attributes redacted
}

通过检查 MESSAGE 事件载荷 (chat.messagePayload.message.matchedUrl.url) 中是否存在 matchedUrl 字段，您的 Chat 应用可以向包含预览链接的消息添加信息。您的 Chat 应用可以回复基本文本消息，也可以附加卡片。

通过短信回复

对于基本响应，您的 Chat 应用可以通过回复链接来预览链接，回复内容为简单文本消息。此示例附加了一条消息，其中重复了与链接预览网址格式匹配的链接网址。

Node.js

node/chat/preview-link/index.js

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text"
if (chatMessage.matchedUrl.url.includes("text.example.com")) {
  return { hostAppDataAction: { chatDataAction: { createMessageAction: { message: {
    text: 'event.chat.messagePayload.message.matchedUrl.url: ' + chatMessage.matchedUrl.url
  }}}}};
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Python

python/chat/preview-link/main.py

在 GitHub 上查看

# Reply with a text message for URLs of the subdomain "text"
if "text.example.com" in chatMessage.get('matchedUrl').get('url'):
  return { 'hostAppDataAction': { 'chatDataAction': { 'createMessageAction': { 'message': {
    'text': 'event.chat.messagePayload.message.matchedUrl.url: ' + chatMessage.get('matchedUrl').get('url')
  }}}}}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Java

java/chat/preview-link/src/main/java/com/google/chat/previewLink/App.java

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text"
if (chatMessage.at("/matchedUrl/url").asText().contains("text.example.com")) {
  return new GenericJson() {{
    put("hostAppDataAction", new GenericJson() {{
      put("chatDataAction", new GenericJson() {{
        put("createMessageAction", new GenericJson() {{
          put("message", new Message()
            .setText("event.chat.messagePayload.message.matchedUrl.url: " + chatMessage.at("/matchedUrl/url").asText()));
        }});
      }});
    }});
  }};
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Apps 脚本

apps-script/chat/preview-link/preview-link.gs

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text".
if (chatMessage.matchedUrl.url.includes("text.example.com")) {
  return { hostAppDataAction: { chatDataAction: { createMessageAction: { message: {
    text: 'event.chat.messagePayload.message.matchedUrl.url: ' + chatMessage.matchedUrl.url
  }}}}};
}

附加可预览链接的卡片

如需将卡片附加到预览链接，请返回包含 UpdateInlinePreviewAction 类型 ChatDataActionMarkup 对象的 DataActions 操作。

在以下示例中，Chat 应用会向包含网址格式 support.example.com 的消息添加预览卡片。

Node.js

node/chat/preview-link/index.js

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support"
if (chatMessage.matchedUrl.url.includes("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  return { hostAppDataAction: { chatDataAction: { updateInlinePreviewAction: { cardsV2: [{
    cardId: 'attachCard',
    card: {
      header: {
        title: 'Example Customer Service Case',
        subtitle: 'Case basics',
      },
      sections: [{ widgets: [
      { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
      { decoratedText: { topLabel: 'Assignee', text: 'Charlie'}},
      { decoratedText: { topLabel: 'Status', text: 'Open'}},
      { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
      { buttonList: { buttons: [{
        text: 'OPEN CASE',
        onClick: { openLink: {
          url: 'https://support.example.com/orders/case123'
        }},
      }, {
        text: 'RESOLVE CASE',
        onClick: { openLink: {
          url: 'https://support.example.com/orders/case123?resolved=y',
        }},
      }, {
        text: 'ASSIGN TO ME',
        onClick: { action: { function: FUNCTION_URL }}
      }]}}
      ]}]
    }
  }]}}}};
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Python

python/chat/preview-link/main.py

在 GitHub 上查看

# Attach a card to the message for URLs of the subdomain "support"
if "support.example.com" in chatMessage.get('matchedUrl').get('url'):
  # A hard-coded card is used in this example. In a real-life scenario,
  # the case information would be fetched and used to build the card.
  return { 'hostAppDataAction': { 'chatDataAction': { 'updateInlinePreviewAction': { 'cardsV2': [{
    'cardId': 'attachCard',
    'card': {
      'header': {
        'title': 'Example Customer Service Case',
        'subtitle': 'Case basics',
      },
      'sections': [{ 'widgets': [
      { 'decoratedText': { 'topLabel': 'Case ID', 'text': 'case123'}},
      { 'decoratedText': { 'topLabel': 'Assignee', 'text': 'Charlie'}},
      { 'decoratedText': { 'topLabel': 'Status', 'text': 'Open'}},
      { 'decoratedText': { 'topLabel': 'Subject', 'text': 'It won\'t turn on...' }},
      { 'buttonList': { 'buttons': [{
        'text': 'OPEN CASE',
        'onClick': { 'openLink': {
          'url': 'https://support.example.com/orders/case123'
        }},
      }, {
        'text': 'RESOLVE CASE',
        'onClick': { 'openLink': {
          'url': 'https://support.example.com/orders/case123?resolved=y',
        }},
      }, {
        'text': 'ASSIGN TO ME',
        'onClick': { 'action': { 'function': FUNCTION_URL }}
      }]}}
      ]}]
    }
  }]}}}}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Java

java/chat/preview-link/src/main/java/com/google/chat/previewLink/App.java

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support"
if (chatMessage.at("/matchedUrl/url").asText().contains("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  CardWithId cardV2 = new CardWithId()
    .setCardId("attachCard")
    .setCard(new GoogleAppsCardV1Card()
      .setHeader(new GoogleAppsCardV1CardHeader()
        .setTitle("Example Customer Service Case")
        .setSubtitle("Case basics"))
      .setSections(List.of(new GoogleAppsCardV1Section().setWidgets(List.of(
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Case ID")
          .setText("case123")),
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Assignee")
          .setText("Charlie")),
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Status")
          .setText("Open")),
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Subject")
          .setText("It won't turn on...")),
        new GoogleAppsCardV1Widget().setButtonList(new GoogleAppsCardV1ButtonList()
          .setButtons(List.of(
            new GoogleAppsCardV1Button()
              .setText("OPEN CASE")
            .setOnClick(new GoogleAppsCardV1OnClick()
                .setOpenLink(new GoogleAppsCardV1OpenLink()
                  .setUrl("https://support.example.com/orders/case123"))),
            new GoogleAppsCardV1Button()
              .setText("RESOLVE CASE")
            .setOnClick(new GoogleAppsCardV1OnClick()
                .setOpenLink(new GoogleAppsCardV1OpenLink()
                  .setUrl("https://support.example.com/orders/case123?resolved=y"))),
            new GoogleAppsCardV1Button()
              .setText("ASSIGN TO ME")
              .setOnClick(new GoogleAppsCardV1OnClick()
                .setAction(new GoogleAppsCardV1Action().setFunction(FUNCTION_URL)))
          ))
        )
      ))))
    );

  return new GenericJson() {{
    put("hostAppDataAction", new GenericJson() {{
      put("chatDataAction", new GenericJson() {{
        put("updateInlinePreviewAction", new GenericJson() {{
          put("cardsV2", List.of(cardV2));
        }});
      }});
    }});
  }};
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Apps 脚本

apps-script/chat/preview-link/preview-link.gs

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support".
if (chatMessage.matchedUrl.url.includes("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  return { hostAppDataAction: { chatDataAction: { updateInlinePreviewAction: { cardsV2: [{
    cardId: 'attachCard',
    card: {
      header: {
        title: 'Example Customer Service Case',
        subtitle: 'Case summary',
      },
      sections: [{ widgets: [
      { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
      { decoratedText: { topLabel: 'Assignee', text: 'Charlie'}},
      { decoratedText: { topLabel: 'Status', text: 'Open'}},
      { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
      { buttonList: { buttons: [{
        text: 'OPEN CASE',
        onClick: { openLink: {
          url: 'https://support.example.com/orders/case123'
        }},
      }, {
        text: 'RESOLVE CASE',
        onClick: { openLink: {
          url: 'https://support.example.com/orders/case123?resolved=y',
        }},
      }, {
        text: 'ASSIGN TO ME',
        // Clicking this button triggers the execution of the function
        // "assign" from the Apps Script project.
        onClick: { action: { function: 'assign'}}
      }]}}
      ]}]
    }
  }]}}}};
}

更新链接预览卡片

当用户与链接预览卡片互动时（例如点击卡片上的按钮），您的 Chat 应用可以更新该卡片。

如需更新卡片，Chat 应用必须返回操作 DataActions，并附带以下 ChatDataActionMarkup 对象之一：

• 如果用户发送了消息，则返回 UpdateMessageAction 对象。
• 如果消息是由 Chat 应用发送的，则返回 UpdateInlinePreviewAction 对象。

如需确定消息的发送者，请使用事件载荷 (buttonClickedPayload) 检查发送者 (message.sender.type) 是否设置为 HUMAN（用户）或 BOT（聊天应用）。

以下示例展示了聊天应用如何在用户每次点击指派给我按钮时更新链接预览，方法是更新卡片的受让人字段并停用该按钮。

Node.js

node/chat/preview-link/index.js

在 GitHub 上查看

/**
 * Respond to clicks by assigning and updating the card that's attached to a
 * message previewed link of the pattern "support.example.com".
 *
 * @param {Object} chatMessage The chat message object from Google Workspace Add On event.
 * @return {Object} Action response depending on the message author.
 */
function handleCardClick(chatMessage) {
  // Creates the updated card that displays "You" for the assignee
  // and that disables the button.
  //
  // A hard-coded card is used in this example. In a real-life scenario,
  // an actual assign action would be performed before building the card.
  const message = { cardsV2: [{
    cardId: 'attachCard',
    card: {
      header: {
        title: 'Example Customer Service Case',
        subtitle: 'Case basics',
      },
      sections: [{ widgets: [
        { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
        // The assignee is now "You"
        { decoratedText: { topLabel: 'Assignee', text: 'You'}},
        { decoratedText: { topLabel: 'Status', text: 'Open'}},
        { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
        { buttonList: { buttons: [{
          text: 'OPEN CASE',
          onClick: { openLink: {
            url: 'https://support.example.com/orders/case123'
          }},
        }, {
          text: 'RESOLVE CASE',
          onClick: { openLink: {
            url: 'https://support.example.com/orders/case123?resolved=y',
          }},
        }, {
          text: 'ASSIGN TO ME',
          // The button is now disabled
          disabled: true,
          onClick: { action: { function: FUNCTION_URL }}
        }]}}
      ]}]
    }
  }]};

  // Use the adequate action response type. It depends on whether the message
  // the preview link card is attached to was created by a human or a Chat app.
  if(chatMessage.sender.type === 'HUMAN') {
    return { hostAppDataAction: { chatDataAction: { updateInlinePreviewAction: message }}};
  } else {
    return { hostAppDataAction: { chatDataAction: { updateMessageAction: message }}};
  }
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Python

python/chat/preview-link/main.py

在 GitHub 上查看

def handle_card_click(chatMessage: dict) -> dict:
  """Respond to clicks by assigning and updating the card that's attached to a
  message previewed link of the pattern "support.example.com".

  - Reply with text messages that echo "text.example.com" link URLs in messages.
  - Attach cards to messages with "support.example.com" link URLs.

  Args:
      chatMessage (Mapping[str, Any]): The chat message object from Google Workspace Add On event.

  Returns:
      Mapping[str, Any]: Action response depending on the message author.
  """
  # Creates the updated card that displays "You" for the assignee
  # and that disables the button.
  #
  # A hard-coded card is used in this example. In a real-life scenario,
  # an actual assign action would be performed before building the card.
  message = { 'cardsV2': [{
    'cardId': 'attachCard',
    'card': {
      'header': {
        'title': 'Example Customer Service Case',
        'subtitle': 'Case basics',
      },
      'sections': [{ 'widgets': [
      { 'decoratedText': { 'topLabel': 'Case ID', 'text': 'case123'}},
      # The assignee is now "You"
      { 'decoratedText': { 'topLabel': 'Assignee', 'text': 'You'}},
      { 'decoratedText': { 'topLabel': 'Status', 'text': 'Open'}},
      { 'decoratedText': { 'topLabel': 'Subject', 'text': 'It won\'t turn on...' }},
      { 'buttonList': { 'buttons': [{
        'text': 'OPEN CASE',
        'onClick': { 'openLink': {
          'url': 'https://support.example.com/orders/case123'
        }},
      }, {
        'text': 'RESOLVE CASE',
        'onClick': { 'openLink': {
          'url': 'https://support.example.com/orders/case123?resolved=y',
        }},
      }, {
        'text': 'ASSIGN TO ME',
        # The button is now disabled
        'disabled': True,
        'onClick': { 'action': { 'function': FUNCTION_URL }}
      }]}}
      ]}]
    }
  }]}

  # Use the adequate action response type. It depends on whether the message
  # the preview link card is attached to was created by a human or a Chat app.
  if chatMessage.get('sender').get('type') == 'HUMAN':
    return { 'hostAppDataAction': { 'chatDataAction': { 'updateInlinePreviewAction': message }}}
  else:
    return { 'hostAppDataAction': { 'chatDataAction': { 'updateMessageAction': message }}}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Java

java/chat/preview-link/src/main/java/com/google/chat/previewLink/App.java

在 GitHub 上查看

/**
 * Respond to clicks by assigning and updating the card that's attached to a
 * message previewed link of the pattern "support.example.com".
 *
 * @param chatMessage The chat message object from Google Workspace Add On event.
 * @return Action response depending on the message author.
 */
GenericJson handleCardClick(JsonNode chatMessage) {
  // Creates the updated card that displays "You" for the assignee
  // and that disables the button.
  //
  // A hard-coded card is used in this example. In a real-life scenario,
  // an actual assign action would be performed before building the card.
  Message message = new Message().setCardsV2(List.of(new CardWithId()
    .setCardId("attachCard")
    .setCard(new GoogleAppsCardV1Card()
      .setHeader(new GoogleAppsCardV1CardHeader()
        .setTitle("Example Customer Service Case")
        .setSubtitle("Case basics"))
      .setSections(List.of(new GoogleAppsCardV1Section().setWidgets(List.of(
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Case ID")
          .setText("case123")),
        // The assignee is now "You"
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Assignee")
          .setText("You")),
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Status")
          .setText("Open")),
        new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
          .setTopLabel("Subject")
          .setText("It won't turn on...")),
        new GoogleAppsCardV1Widget().setButtonList(new GoogleAppsCardV1ButtonList()
          .setButtons(List.of(
            new GoogleAppsCardV1Button()
              .setText("OPEN CASE")
              .setOnClick(new GoogleAppsCardV1OnClick()
                .setOpenLink(new GoogleAppsCardV1OpenLink()
                  .setUrl("https://support.example.com/orders/case123"))),
            new GoogleAppsCardV1Button()
              .setText("RESOLVE CASE")
              .setOnClick(new GoogleAppsCardV1OnClick()
                .setOpenLink(new GoogleAppsCardV1OpenLink()
                  .setUrl("https://support.example.com/orders/case123?resolved=y"))),
            new GoogleAppsCardV1Button()
              .setText("ASSIGN TO ME")
              // The button is now disabled
              .setDisabled(true)
              .setOnClick(new GoogleAppsCardV1OnClick()
                .setAction(new GoogleAppsCardV1Action().setFunction(FUNCTION_URL)))
          ))
        )
      ))))
    )
  ));

  // Use the adequate action response type. It depends on whether the message
  // the preview link card is attached to was created by a human or a Chat app.
  if("HUMAN".equals(chatMessage.at("/sender/type").asText())) {
    return new GenericJson() {{
      put("hostAppDataAction", new GenericJson() {{
        put("chatDataAction", new GenericJson() {{
          put("updateInlinePreviewAction", message);
        }});
      }});
    }};
  } else {
    return new GenericJson() {{
      put("hostAppDataAction", new GenericJson() {{
        put("chatDataAction", new GenericJson() {{
          put("updateMessageAction", message);
        }});
      }});
    }};
  }
}

将 FUNCTION_URL 替换为处理按钮点击事件的 HTTP 端点。

Apps 脚本

apps-script/chat/preview-link/preview-link.gs

在 GitHub 上查看

/**
 * Assigns and updates the card that's attached to a message with a
 * previewed link of the pattern "support.example.com".
 *
 * @param {Object} event The event object from the Google Workspace add-on.
 * @return {Object} Action response depending on the message author.
 */
function assign(event) {
  // Creates the updated card that displays "You" for the assignee
  // and that disables the button.
  //
  // A hard-coded card is used in this example. In a real-life scenario,
  // an actual assign action would be performed before building the card.
  const message = { cardsV2: [{
    cardId: 'attachCard',
    card: {
      header: {
        title: 'Example Customer Service Case',
        subtitle: 'Case summary',
      },
      sections: [{ widgets: [
        { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
        // The assignee is now "You"
        { decoratedText: { topLabel: 'Assignee', text: 'You'}},
        { decoratedText: { topLabel: 'Status', text: 'Open'}},
        { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
        { buttonList: { buttons: [{
          text: 'OPEN CASE',
          onClick: { openLink: {
            url: 'https://support.example.com/orders/case123'
          }},
        }, {
          text: 'RESOLVE CASE',
          onClick: { openLink: {
            url: 'https://support.example.com/orders/case123?resolved=y',
          }},
        }, {
          text: 'ASSIGN TO ME',
          // The button is now disabled
          disabled: true,
          onClick: { action: { function: 'assign'}}
        }]}}
      ]}]
    }
  }]};

  // Use the adequate action response type. It depends on whether the message
  // the preview link card is attached to was created by a human or a Chat app.
  if(event.chat.buttonClickedPayload.message.sender.type === 'HUMAN') {
    return { hostAppDataAction: { chatDataAction: { updateInlinePreviewAction: message }}};
  } else {
    return { hostAppDataAction: { chatDataAction: { updateMessageAction: message }}};
  }
}

限制和注意事项

为 Chat 应用配置链接预览时，请注意以下限制和注意事项：

• 每个 Chat 应用最多支持 5 个网址格式的链接预览。
• 聊天应用会预览每条消息中的一个链接。如果一条消息中包含多个可预览的链接，系统只会预览第一个可预览的链接。
• 聊天应用仅预览以 https:// 开头的链接，因此会预览 https://support.example.com/cases/，但不会预览 support.example.com/cases/。
• 除非消息包含其他会发送到 Chat 应用的信息（例如斜杠命令），否则链接预览只会将链接网址发送到 Chat 应用。
• 如果用户发布链接，Chat 应用只有在用户与链接预览卡片互动（例如点击按钮）时才能更新该卡片。您无法在 Message 资源上调用 Chat API 的 update() 方法来异步更新用户的消息。
• 聊天应用必须为聊天室中的所有人预览链接，因此消息必须省略 privateMessageViewer 字段。

调试链接预览

在实现链接预览功能时，您可能需要通过读取应用的日志来调试 Chat 应用。如需读取日志，请访问 Google Cloud 控制台中的Logs Explorer。

非插件的 Chat 应用：预览链接

以下文档适用于非 Google Workspace 加载项的 Chat 应用。如需迁移非插件的 Chat 应用，请参阅将 Google Chat 应用转换为 Google Workspace 加载项。

在包含非插件 Chat 应用的 Chat 聊天室中，当某人的消息包含与链接预览网址格式匹配的链接时，Chat 应用会收到 MESSAGE 互动事件。互动事件的 JSON 载荷包含 matchedUrl 字段：

JSON

message: {
  matchedUrl: {
    url: "https://support.example.com/cases/case123"
  },
  ... // other message attributes redacted
}

通过检查 MESSAGE 事件载荷中是否存在 matchedUrl 字段，非插件的 Chat 应用可以向包含预览链接的消息添加信息。

通过短信回复

对于基本响应，非插件的 Chat 应用可以通过回复链接来预览链接，回复内容为纯文本消息。此示例附加了一条消息，其中重复了与链接预览网址格式匹配的链接网址：

Node.js

node/preview-link/index.js

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text"
if (event.message.matchedUrl.url.includes("text.example.com")) {
  return {
    text: 'event.message.matchedUrl.url: ' + event.message.matchedUrl.url
  };
}

Python

python/preview-link/main.py

在 GitHub 上查看

# Reply with a text message for URLs of the subdomain "text"
if 'text.example.com' in event.get('message').get('matchedUrl').get('url'):
  return {
    'text': 'event.message.matchedUrl.url: ' +
            event.get('message').get('matchedUrl').get('url')
  }

Java

java/preview-link/src/main/java/com/google/chat/preview/App.java

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text"
if (event.at("/message/matchedUrl/url").asText().contains("text.example.com")) {
  return new Message().setText("event.message.matchedUrl.url: " +
    event.at("/message/matchedUrl/url").asText());
}

Apps 脚本

apps-script/preview-link/preview-link.gs

在 GitHub 上查看

// Reply with a text message for URLs of the subdomain "text"
if (event.message.matchedUrl.url.includes("text.example.com")) {
  return {
    text: 'event.message.matchedUrl.url: ' + event.message.matchedUrl.url
  };
}

附加可预览链接的卡片

如需将卡片附加到聊天应用（非插件）中预览的链接，请返回类型为 UPDATE_USER_MESSAGE_CARDS 的 ActionResponse。此示例附加了一张基本卡片：

Node.js

node/preview-link/index.js

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support"
if (event.message.matchedUrl.url.includes("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  return {
    actionResponse: { type: 'UPDATE_USER_MESSAGE_CARDS' },
    cardsV2: [{
      cardId: 'attachCard',
      card: {
        header: {
          title: 'Example Customer Service Case',
          subtitle: 'Case basics',
        },
        sections: [{ widgets: [
          { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
          { decoratedText: { topLabel: 'Assignee', text: 'Charlie'}},
          { decoratedText: { topLabel: 'Status', text: 'Open'}},
          { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
          { buttonList: { buttons: [{
            text: 'OPEN CASE',
            onClick: { openLink: {
              url: 'https://support.example.com/orders/case123'
            }},
          }, {
            text: 'RESOLVE CASE',
            onClick: { openLink: {
              url: 'https://support.example.com/orders/case123?resolved=y',
            }},
          }, {
            text: 'ASSIGN TO ME',
            onClick: { action: { function: 'assign'}}
          }]}}
        ]}]
      }
    }]
  };
}

Python

python/preview-link/main.py

在 GitHub 上查看

# Attach a card to the message for URLs of the subdomain "support"
if 'support.example.com' in event.get('message').get('matchedUrl').get('url'):
  # A hard-coded card is used in this example. In a real-life scenario,
  # the case information would be fetched and used to build the card.
  return {
    'actionResponse': { 'type': 'UPDATE_USER_MESSAGE_CARDS' },
    'cardsV2': [{
      'cardId': 'attachCard',
      'card': {
        'header': {
          'title': 'Example Customer Service Case',
          'subtitle': 'Case basics',
        },
        'sections': [{ 'widgets': [
          { 'decoratedText': { 'topLabel': 'Case ID', 'text': 'case123'}},
          { 'decoratedText': { 'topLabel': 'Assignee', 'text': 'Charlie'}},
          { 'decoratedText': { 'topLabel': 'Status', 'text': 'Open'}},
          { 'decoratedText': { 'topLabel': 'Subject', 'text': 'It won\'t turn on...' }},
          { 'buttonList': { 'buttons': [{
            'text': 'OPEN CASE',
            'onClick': { 'openLink': {
              'url': 'https://support.example.com/orders/case123'
            }},
          }, {
            'text': 'RESOLVE CASE',
            'onClick': { 'openLink': {
              'url': 'https://support.example.com/orders/case123?resolved=y',
            }},
          }, {
            'text': 'ASSIGN TO ME',
            'onClick': { 'action': { 'function': 'assign'}}
          }]}}
        ]}]
      }
    }]
  }

Java

java/preview-link/src/main/java/com/google/chat/preview/App.java

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support"
if (event.at("/message/matchedUrl/url").asText().contains("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  return new Message()
    .setActionResponse(new ActionResponse()
      .setType("UPDATE_USER_MESSAGE_CARDS"))
    .setCardsV2(List.of(new CardWithId()
      .setCardId("attachCard")
      .setCard(new GoogleAppsCardV1Card()
        .setHeader(new GoogleAppsCardV1CardHeader()
          .setTitle("Example Customer Service Case")
          .setSubtitle("Case basics"))
        .setSections(List.of(new GoogleAppsCardV1Section().setWidgets(List.of(
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Case ID")
            .setText("case123")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Assignee")
            .setText("Charlie")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Status")
            .setText("Open")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Subject")
            .setText("It won't turn on...")),
          new GoogleAppsCardV1Widget()
            .setButtonList(new GoogleAppsCardV1ButtonList().setButtons(List.of(
              new GoogleAppsCardV1Button()
                .setText("OPEN CASE")
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setOpenLink(new GoogleAppsCardV1OpenLink()
                    .setUrl("https://support.example.com/orders/case123"))),
              new GoogleAppsCardV1Button()
                .setText("RESOLVE CASE")
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setOpenLink(new GoogleAppsCardV1OpenLink()
                    .setUrl("https://support.example.com/orders/case123?resolved=y"))),
              new GoogleAppsCardV1Button()
                .setText("ASSIGN TO ME")
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setAction(new GoogleAppsCardV1Action().setFunction("assign")))))))))))));
}

Apps 脚本

此示例通过返回 card JSON 来发送卡片消息。您还可以使用 Apps 脚本卡片服务。

apps-script/preview-link/preview-link.gs

在 GitHub 上查看

// Attach a card to the message for URLs of the subdomain "support"
if (event.message.matchedUrl.url.includes("support.example.com")) {
  // A hard-coded card is used in this example. In a real-life scenario,
  // the case information would be fetched and used to build the card.
  return {
    actionResponse: { type: 'UPDATE_USER_MESSAGE_CARDS' },
    cardsV2: [{
      cardId: 'attachCard',
      card: {
        header: {
          title: 'Example Customer Service Case',
          subtitle: 'Case basics',
        },
        sections: [{ widgets: [
          { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
          { decoratedText: { topLabel: 'Assignee', text: 'Charlie'}},
          { decoratedText: { topLabel: 'Status', text: 'Open'}},
          { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
          { buttonList: { buttons: [{
            text: 'OPEN CASE',
            onClick: { openLink: {
              url: 'https://support.example.com/orders/case123'
            }},
          }, {
            text: 'RESOLVE CASE',
            onClick: { openLink: {
              url: 'https://support.example.com/orders/case123?resolved=y',
            }},
          }, {
            text: 'ASSIGN TO ME',
            onClick: { action: { function: 'assign'}}
          }]}}
        ]}]
      }
    }]
  };
}

更新链接预览卡片

如需在非插件的 Chat 应用中更新链接预览卡片，请处理 CARD_CLICKED 互动事件，并根据包含链接预览的消息的发送者返回 actionResponse：

• 如果消息是由用户发送的，请将 actionResponse.type 设置为 UPDATE_USER_MESSAGE_CARDS。
• 如果消息是由 Chat 应用发送的，请将 actionResponse.type 设置为 UPDATE_MESSAGE。

如需确定消息的发送者，您可以使用互动事件的 message.sender.type 字段来查看发送者是 HUMAN 用户还是 BOT。

以下示例展示了非插件的 Chat 应用如何通过更新卡片的 Assignee 字段并停用按钮，在用户每次点击 Assign to Me 按钮时更新链接预览：

Node.js

node/preview-link/index.js

在 GitHub 上查看

/**
 * Updates a card that was attached to a message with a previewed link.
 *
 * @param {Object} event The event object from Chat.
 *
 * @return {Object} Response from the Chat app. Either a new card attached to
 * the message with the previewed link, or an update to an existing card.
 */
function onCardClick(event) {
  // To respond to the correct button, checks the button's actionMethodName.
  if (event.action.actionMethodName === 'assign') {
    // A hard-coded card is used in this example. In a real-life scenario,
    // an actual assign action would be performed before building the card.

    // Checks whether the message event originated from a human or a Chat app
    // and sets actionResponse.type to "UPDATE_USER_MESSAGE_CARDS if human or
    // "UPDATE_MESSAGE" if Chat app.
    const actionResponseType = event.message.sender.type === 'HUMAN' ?
      'UPDATE_USER_MESSAGE_CARDS' :
      'UPDATE_MESSAGE';

    // Returns the updated card that displays "You" for the assignee
    // and that disables the button.
    return {
      actionResponse: { type: actionResponseType },
      cardsV2: [{
        cardId: 'attachCard',
        card: {
          header: {
            title: 'Example Customer Service Case',
            subtitle: 'Case basics',
          },
          sections: [{ widgets: [
            { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
            // The assignee is now "You"
            { decoratedText: { topLabel: 'Assignee', text: 'You'}},
            { decoratedText: { topLabel: 'Status', text: 'Open'}},
            { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
            { buttonList: { buttons: [{
              text: 'OPEN CASE',
              onClick: { openLink: {
                url: 'https://support.example.com/orders/case123'
              }},
            }, {
              text: 'RESOLVE CASE',
              onClick: { openLink: {
                url: 'https://support.example.com/orders/case123?resolved=y',
              }},
            }, {
              text: 'ASSIGN TO ME',
              // The button is now disabled
              disabled: true,
              onClick: { action: { function: 'assign'}}
            }]}}
          ]}]
        }
      }]
    };
  }
}

Python

python/preview-link/main.py

在 GitHub 上查看

def on_card_click(event: dict) -> dict:
  """Updates a card that was attached to a message with a previewed link."""
  # To respond to the correct button, checks the button's actionMethodName.
  if 'assign' == event.get('action').get('actionMethodName'):
    # A hard-coded card is used in this example. In a real-life scenario,
    # an actual assign action would be performed before building the card.

    # Checks whether the message event originated from a human or a Chat app
    # and sets actionResponse.type to "UPDATE_USER_MESSAGE_CARDS if human or
    # "UPDATE_MESSAGE" if Chat app.
    actionResponseType = 'UPDATE_USER_MESSAGE_CARDS' if \
      event.get('message').get('sender').get('type') == 'HUMAN' else \
      'UPDATE_MESSAGE'

    # Returns the updated card that displays "You" for the assignee
    # and that disables the button.
    return {
      'actionResponse': { 'type': actionResponseType },
      'cardsV2': [{
        'cardId': 'attachCard',
        'card': {
          'header': {
            'title': 'Example Customer Service Case',
            'subtitle': 'Case basics',
          },
          'sections': [{ 'widgets': [
            { 'decoratedText': { 'topLabel': 'Case ID', 'text': 'case123'}},
            # The assignee is now "You"
            { 'decoratedText': { 'topLabel': 'Assignee', 'text': 'You'}},
            { 'decoratedText': { 'topLabel': 'Status', 'text': 'Open'}},
            { 'decoratedText': { 'topLabel': 'Subject', 'text': 'It won\'t turn on...' }},
            { 'buttonList': { 'buttons': [{
              'text': 'OPEN CASE',
              'onClick': { 'openLink': {
                'url': 'https://support.example.com/orders/case123'
              }},
            }, {
              'text': 'RESOLVE CASE',
              'onClick': { 'openLink': {
                'url': 'https://support.example.com/orders/case123?resolved=y',
              }},
            }, {
              'text': 'ASSIGN TO ME',
              # The button is now disabled
              'disabled': True,
              'onClick': { 'action': { 'function': 'assign'}}
            }]}}
          ]}]
        }
      }]
    }

Java

java/preview-link/src/main/java/com/google/chat/preview/App.java

在 GitHub 上查看

// Updates a card that was attached to a message with a previewed link.
Message onCardClick(JsonNode event) {
  // To respond to the correct button, checks the button's actionMethodName.
  if (event.at("/action/actionMethodName").asText().equals("assign")) {
    // A hard-coded card is used in this example. In a real-life scenario,
    // an actual assign action would be performed before building the card.

    // Checks whether the message event originated from a human or a Chat app
    // and sets actionResponse.type to "UPDATE_USER_MESSAGE_CARDS if human or
    // "UPDATE_MESSAGE" if Chat app.
    String actionResponseType =
      event.at("/message/sender/type").asText().equals("HUMAN")
      ? "UPDATE_USER_MESSAGE_CARDS" : "UPDATE_MESSAGE";

    // Returns the updated card that displays "You" for the assignee
    // and that disables the button.
    return new Message()
    .setActionResponse(new ActionResponse()
      .setType(actionResponseType))
    .setCardsV2(List.of(new CardWithId()
      .setCardId("attachCard")
      .setCard(new GoogleAppsCardV1Card()
        .setHeader(new GoogleAppsCardV1CardHeader()
          .setTitle("Example Customer Service Case")
          .setSubtitle("Case basics"))
        .setSections(List.of(new GoogleAppsCardV1Section().setWidgets(List.of(
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Case ID")
            .setText("case123")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Assignee")
            // The assignee is now "You"
            .setText("You")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Status")
            .setText("Open")),
          new GoogleAppsCardV1Widget().setDecoratedText(new GoogleAppsCardV1DecoratedText()
            .setTopLabel("Subject")
            .setText("It won't turn on...")),
          new GoogleAppsCardV1Widget()
            .setButtonList(new GoogleAppsCardV1ButtonList().setButtons(List.of(
              new GoogleAppsCardV1Button()
                .setText("OPEN CASE")
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setOpenLink(new GoogleAppsCardV1OpenLink()
                    .setUrl("https://support.example.com/orders/case123"))),
              new GoogleAppsCardV1Button()
                .setText("RESOLVE CASE")
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setOpenLink(new GoogleAppsCardV1OpenLink()
                    .setUrl("https://support.example.com/orders/case123?resolved=y"))),
              new GoogleAppsCardV1Button()
                .setText("ASSIGN TO ME")
                // The button is now disabled
                .setDisabled(true)
                .setOnClick(new GoogleAppsCardV1OnClick()
                  .setAction(new GoogleAppsCardV1Action().setFunction("assign")))))))))))));
  }
  return null;
}

Apps 脚本

此示例通过返回 card JSON 来发送卡片消息。您还可以使用 Apps 脚本卡片服务。

apps-script/preview-link/preview-link.gs

在 GitHub 上查看

/**
 * Updates a card that was attached to a message with a previewed link.
 *
 * @param {Object} event The event object from Chat.
 *
 * @return {Object} Response from the Chat app. Either a new card attached to
 * the message with the previewed link, or an update to an existing card.
 */
function onCardClick(event) {
  // To respond to the correct button, checks the button's actionMethodName.
  if (event.action.actionMethodName === 'assign') {
    // A hard-coded card is used in this example. In a real-life scenario,
    // an actual assign action would be performed before building the card.

    // Checks whether the message event originated from a human or a Chat app
    // and sets actionResponse.type to "UPDATE_USER_MESSAGE_CARDS if human or
    // "UPDATE_MESSAGE" if Chat app.
    const actionResponseType = event.message.sender.type === 'HUMAN' ?
      'UPDATE_USER_MESSAGE_CARDS' :
      'UPDATE_MESSAGE';

    // Returns the updated card that displays "You" for the assignee
    // and that disables the button.
    return {
      actionResponse: { type: actionResponseType },
      cardsV2: [{
        cardId: 'attachCard',
        card: {
          header: {
            title: 'Example Customer Service Case',
            subtitle: 'Case basics',
          },
          sections: [{ widgets: [
            { decoratedText: { topLabel: 'Case ID', text: 'case123'}},
            // The assignee is now "You"
            { decoratedText: { topLabel: 'Assignee', text: 'You'}},
            { decoratedText: { topLabel: 'Status', text: 'Open'}},
            { decoratedText: { topLabel: 'Subject', text: 'It won\'t turn on...' }},
            { buttonList: { buttons: [{
              text: 'OPEN CASE',
              onClick: { openLink: {
                url: 'https://support.example.com/orders/case123'
              }},
            }, {
              text: 'RESOLVE CASE',
              onClick: { openLink: {
                url: 'https://support.example.com/orders/case123?resolved=y',
              }},
            }, {
              text: 'ASSIGN TO ME',
              // The button is now disabled
              disabled: true,
              onClick: { action: { function: 'assign'}}
            }]}}
          ]}]
        }
      }]
    };
  }
}