Resource Orchestration Service:Dynamically display parameters based on dependencies

Template syntax

Specify AssociationProperty and AssociationPropertyMetadata for a parameter to control its visibility based on another parameter's value. In AssociationPropertyMetadata, define a Visible field that uses a function to determine whether to display the parameter. The syntax is as follows:

Visible:
  Condition: Object # Condition to display this parameter.

The Condition field supports the following functions:

• Functions: "Fn::Equals": ["${targetInstanceChargeType}", "PostPaid"].
• Functions: "Fn::Not": ${condition}.
• Functions: "Fn::And": [${condition1}, ${condition2}, ...].
• Functions: "Fn::Or": [${condition1}, ${condition2}, ...].

Template example

In this example, AssociationProperty is set on the targetInstanceChargeType parameter to make it the controlling parameter for the billing method. AssociationPropertyMetadata is then used on dependent parameters to define their visibility conditions. This enables dynamic parameter filtering during stack creation.

ROSTemplateFormatVersion: '2015-09-01'
Description:
  zh-cn: 单实例自定义镜像模板示例，支持创建基础资源配置（VPC、VSwitch、SecurityGroup）或者选择已有基础资源配置，并支持配置ECS的计费方式为包年包月或者按量付费。
  en: An example template for creating a single ECS instance from a custom image. You can either create new base resources (VPC, VSwitch, security group) or use existing ones. Supports both subscription and pay-as-you-go billing methods for the ECS instance.
Parameters:
  targetInstanceChargeType:
    Description:
      name-en: targetInstanceChargeType
      name-zh-cn: 计费方式
    Type: String
    AssociationProperty: ChargeType
  targetPeriodUnit:
    Description:
      name-en: The unit of the subscription period
      name-zh-cn: 包年包月计费方式的时长单位
    Type: String
    AllowedValues:
      - Week
      - Month
    Default: Month
    AssociationPropertyMetadata:
      Visible:
        Condition:
          Fn::Not:
            Fn::Equals:
              - ${targetInstanceChargeType}
              - PostPaid
  targetPeriod:
    Description:
      name-en: The subscription period of the instance
      name-zh-cn: 购买包年包月资源的时长
      en: 'Valid values: 1, 2, 3, and 4 if PeriodUnit is Week. 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 24, 36, 48, and 60 if PeriodUnit is Month.'
      zh-cn: 取值：PeriodUnit取值为Week时：1、2、3、4。PeriodUnit取值为Month时：1、2、3、4、5、6、7、8、9、12、24、36、48、60。
    Type: Number
    AllowedValues:
      - 1
      - 2
      - 3
      - 4
      - 5
      - 6
      - 7
      - 8
      - 9
      - 12
      - 24
      - 36
      - 48
      - 60
    Default: 1
    AssociationPropertyMetadata:
      Visible:
        Condition:
          Fn::Not:
            Fn::Equals:
              - ${targetInstanceChargeType}
              - PostPaid

Parameters:

• targetInstanceChargeType: The billing method. AssociationProperty is set to ChargeType, which means the visibility of other parameters depends on this parameter's value.
• targetPeriodUnit: The period unit. AssociationPropertyMetadata is set to {"Visible": {"Condition": {"Fn::Not": {"Fn::Equals": ["${targetInstanceChargeType}","PostPaid"]}}}}. This condition displays the targetPeriodUnit parameter only when targetInstanceChargeType is not set to PostPaid.
  Note The targetInstanceChargeType parameter accepts PrePaid for the subscription billing method and PostPaid for the pay-as-you-go billing method.
• targetPeriod: The subscription period. AssociationPropertyMetadata is set to {"Visible": {"Condition": {"Fn::Not": {"Fn::Equals": ["${targetInstanceChargeType}","PostPaid"]}}}}. This condition displays the targetPeriod parameter only when targetInstanceChargeType is not set to PostPaid.

Configuration in the console

When you create a stack from this template with the subscription billing method, the ROS console displays the following dependent parameters: PeriodUnit (with options for Week or Month) and Subscription period. If PeriodUnit is set to Week, the valid values for the subscription period are 1, 2, 3, and 4. If PeriodUnit is set to Month, the valid values are 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 24, 36, 48, and 60.