Class MappingTemplate

MappingTemplates for AppSync resolvers.

Inheritance

MappingTemplate

Namespace: Amazon.CDK.AWS.AppSync

Assembly: Amazon.CDK.Lib.dll

Syntax (csharp)

public abstract class MappingTemplate : DeputyBase

Syntax (vb)

Public MustInherit Class MappingTemplate Inherits DeputyBase

Remarks

ExampleMetadata: infused

Examples

// Build a data source for AppSync to access the database.
            GraphqlApi api;
            // Create username and password secret for DB Cluster
            var secret = new DatabaseSecret(this, "AuroraSecret", new DatabaseSecretProps {
                Username = "clusteradmin"
            });

            // The VPC to place the cluster in
            var vpc = new Vpc(this, "AuroraVpc");

            // Create the serverless cluster, provide all values needed to customise the database.
            var cluster = new ServerlessCluster(this, "AuroraCluster", new ServerlessClusterProps {
                Engine = DatabaseClusterEngine.AURORA_MYSQL,
                Vpc = vpc,
                Credentials = new Dictionary<string, string> { { "username", "clusteradmin" } },
                ClusterIdentifier = "db-endpoint-test",
                DefaultDatabaseName = "demos"
            });
            var rdsDS = api.AddRdsDataSource("rds", cluster, secret, "demos");

            // Set up a resolver for an RDS query.
            rdsDS.CreateResolver("QueryGetDemosRdsResolver", new BaseResolverProps {
                TypeName = "Query",
                FieldName = "getDemosRds",
                RequestMappingTemplate = MappingTemplate.FromString(@"
                  {
                    ""version"": ""2018-05-29"",
                    ""statements"": [
                      ""SELECT * FROM demos""
                    ]
                  }
                  "),
                ResponseMappingTemplate = MappingTemplate.FromString(@"
                    $utils.toJson($utils.rds.toJsonObject($ctx.result)[0])
                  ")
            });

            // Set up a resolver for an RDS mutation.
            rdsDS.CreateResolver("MutationAddDemoRdsResolver", new BaseResolverProps {
                TypeName = "Mutation",
                FieldName = "addDemoRds",
                RequestMappingTemplate = MappingTemplate.FromString(@"
                  {
                    ""version"": ""2018-05-29"",
                    ""statements"": [
                      ""INSERT INTO demos VALUES (:id, :version)"",
                      ""SELECT * WHERE id = :id""
                    ],
                    ""variableMap"": {
                      "":id"": $util.toJson($util.autoId()),
                      "":version"": $util.toJson($ctx.args.version)
                    }
                  }
                  "),
                ResponseMappingTemplate = MappingTemplate.FromString(@"
                    $utils.toJson($utils.rds.toJsonObject($ctx.result)[1][0])
                  ")
            });

Synopsis

Constructors

MappingTemplate()

MappingTemplates for AppSync resolvers.

Methods

DynamoDbDeleteItem(string, string)	Mapping template to delete a single item from a DynamoDB table.
DynamoDbGetItem(string, string, bool?)	Mapping template to get a single item from a DynamoDB table.
DynamoDbPutItem(PrimaryKey, AttributeValues)	Mapping template to save a single item to a DynamoDB table.
DynamoDbQuery(KeyCondition, string?, bool?)	Mapping template to query a set of items from a DynamoDB table.
DynamoDbResultItem()	Mapping template for a single result item from DynamoDB.
DynamoDbResultList()	Mapping template for a result list from DynamoDB.
DynamoDbScanTable(bool?)	Mapping template to scan a DynamoDB table to fetch all entries.
FromFile(string)	Create a mapping template from the given file.
FromString(string)	Create a mapping template from the given string.
LambdaRequest(string?, string?)	Mapping template to invoke a Lambda function.
LambdaResult()	Mapping template to return the Lambda result to the caller.
RenderTemplate()	this is called to render the mapping template to a VTL string.

Constructors

MappingTemplate()

MappingTemplates for AppSync resolvers.

protected MappingTemplate()

Remarks

ExampleMetadata: infused

Examples

// Build a data source for AppSync to access the database.
            GraphqlApi api;
            // Create username and password secret for DB Cluster
            var secret = new DatabaseSecret(this, "AuroraSecret", new DatabaseSecretProps {
                Username = "clusteradmin"
            });

            // The VPC to place the cluster in
            var vpc = new Vpc(this, "AuroraVpc");

            // Create the serverless cluster, provide all values needed to customise the database.
            var cluster = new ServerlessCluster(this, "AuroraCluster", new ServerlessClusterProps {
                Engine = DatabaseClusterEngine.AURORA_MYSQL,
                Vpc = vpc,
                Credentials = new Dictionary<string, string> { { "username", "clusteradmin" } },
                ClusterIdentifier = "db-endpoint-test",
                DefaultDatabaseName = "demos"
            });
            var rdsDS = api.AddRdsDataSource("rds", cluster, secret, "demos");

            // Set up a resolver for an RDS query.
            rdsDS.CreateResolver("QueryGetDemosRdsResolver", new BaseResolverProps {
                TypeName = "Query",
                FieldName = "getDemosRds",
                RequestMappingTemplate = MappingTemplate.FromString(@"
                  {
                    ""version"": ""2018-05-29"",
                    ""statements"": [
                      ""SELECT * FROM demos""
                    ]
                  }
                  "),
                ResponseMappingTemplate = MappingTemplate.FromString(@"
                    $utils.toJson($utils.rds.toJsonObject($ctx.result)[0])
                  ")
            });

            // Set up a resolver for an RDS mutation.
            rdsDS.CreateResolver("MutationAddDemoRdsResolver", new BaseResolverProps {
                TypeName = "Mutation",
                FieldName = "addDemoRds",
                RequestMappingTemplate = MappingTemplate.FromString(@"
                  {
                    ""version"": ""2018-05-29"",
                    ""statements"": [
                      ""INSERT INTO demos VALUES (:id, :version)"",
                      ""SELECT * WHERE id = :id""
                    ],
                    ""variableMap"": {
                      "":id"": $util.toJson($util.autoId()),
                      "":version"": $util.toJson($ctx.args.version)
                    }
                  }
                  "),
                ResponseMappingTemplate = MappingTemplate.FromString(@"
                    $utils.toJson($utils.rds.toJsonObject($ctx.result)[1][0])
                  ")
            });

Methods

DynamoDbDeleteItem(string, string)

Mapping template to delete a single item from a DynamoDB table.

public static MappingTemplate DynamoDbDeleteItem(string keyName, string idArg)

Parameters

keyName string: the name of the hash key field.
idArg string: the name of the Mutation argument.

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbGetItem(string, string, bool?)

Mapping template to get a single item from a DynamoDB table.

public static MappingTemplate DynamoDbGetItem(string keyName, string idArg, bool? consistentRead = null)

Parameters

keyName string: the name of the hash key field.
idArg string: the name of the Query argument.
consistentRead bool?: the name of the hash key field.

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbPutItem(PrimaryKey, AttributeValues)

Mapping template to save a single item to a DynamoDB table.

public static MappingTemplate DynamoDbPutItem(PrimaryKey key, AttributeValues values)

Parameters

key PrimaryKey: the assigment of Mutation values to the primary key.
values AttributeValues: the assignment of Mutation values to the table attributes.

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbQuery(KeyCondition, string?, bool?)

Mapping template to query a set of items from a DynamoDB table.

public static MappingTemplate DynamoDbQuery(KeyCondition cond, string? indexName = null, bool? consistentRead = null)

Parameters

cond KeyCondition: the key condition for the query.
indexName string: the key condition for the query.
consistentRead bool?: the key condition for the query.

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbResultItem()

Mapping template for a single result item from DynamoDB.

public static MappingTemplate DynamoDbResultItem()

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbResultList()

Mapping template for a result list from DynamoDB.

public static MappingTemplate DynamoDbResultList()

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

DynamoDbScanTable(bool?)

Mapping template to scan a DynamoDB table to fetch all entries.

public static MappingTemplate DynamoDbScanTable(bool? consistentRead = null)

Parameters

consistentRead bool?

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

FromFile(string)

Create a mapping template from the given file.

public static MappingTemplate FromFile(string fileName)

Parameters

fileName string

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

FromString(string)

Create a mapping template from the given string.

public static MappingTemplate FromString(string template)

Parameters

template string

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

LambdaRequest(string?, string?)

Mapping template to invoke a Lambda function.

public static MappingTemplate LambdaRequest(string? payload = null, string? operation = null)

Parameters

payload string: the VTL template snippet of the payload to send to the lambda.
operation string: the type of operation AppSync should perform on the data source.

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

LambdaResult()

Mapping template to return the Lambda result to the caller.

public static MappingTemplate LambdaResult()

Returns

MappingTemplate

Remarks

ExampleMetadata: infused

RenderTemplate()

this is called to render the mapping template to a VTL string.

public abstract string RenderTemplate()

Returns

string

Remarks

ExampleMetadata: infused