ScriptingService

On Hive Node, in order to support Vault data sharing to designated or all visitors, a Scripting Service is provided. Scripting Service provides executable scripts to share data (file or database data) in the Vault with others. The controller of the data designs and registers the script, and the user of the data executes the script to operate the data.

An example of registration scripts is as follows:

Vault vault = new Vault(context, getVaultProviderAddress());
ScriptingService scriptingService = vault.getScriptingService();

// The condition to restrict the user DID.
ObjectNode filter = JsonNodeFactory.instance.objectNode();
filter.put("collection",ScriptConst.COLLECTION_GROUP_MESSAGE);
filter.put("did","$caller_did");
// The message is for inserting to the COLLECTION_GROUP_MESSAGE.
ObjectNode msgDoc = JsonNodeFactory.instance.objectNode();
msgDoc.put("author", "$params.author");
msgDoc.put("content", "$params.content");
ObjectNode options = JsonNodeFactory.instance.objectNode();
options.put("bypass_document_validation", false);
options.put("ordered", true);
// register the script for caller to insert message to COLLECTION_GROUP_MESSAGE
scriptingService.registerScript(ScriptConst.SCRIPT_NAME,
        new QueryHasResultCondition("get_group_message", ScriptConst.COLLECTION_GROUP, filter),
        new InsertExecutable(ScriptConst.SCRIPT_NAME, ScriptConst.COLLECTION_GROUP_MESSAGE, msgDoc, options),
        false, false)
    .thenAcceptAsync(result -> {
        System.out.println("Successfully get the result.");
    }).exceptionally(ex -> {
        ex.printStackTrace();
        return null;
    });

This example demonstrates how to register a script. When doing so, you need to set the condition to restrict the data users. In addition, the content of the script (executable) is a template, which allows the user who calls the script to insert the content (type is InsertExecutable) into the data table. At the same time, the script limits the data that data visitors can access (parameters defined by $params). After registering the script, visitors who meet the conditions can insert data by executing the script. The usage scenario here is to send messages to the Vault of the data controller.

Register Script

According to the design of Scripting service, the controller of scripts can register 8 different types of scripts, share file contents, and perform database operations.

• Insert database data

• Update database data

• Delete database data

• Query database data

• Upload file

• Download file

• Get file attribute information

• Get file Hash value

Script data related to specific types contains two pieces of content:

• condition: the conditions set for the visitor. When the visitor executes the script, the correct execution effect can be obtained only if the conditions are met.

• executable: the definition area of the script, which defines the type and parameter template of the specified type of script.

The following is a method prototype of the registration script. The parameters for registering the script include: the name of the script, the conditions for executing the script, the content of the script, whether anonymous users are allowed, and if anonymous applications are allowed.

CompletableFuture<Void> registerScript(String name, Executable executable);
CompletableFuture<Void> registerScript(String name, Condition condition, Executable executable);
CompletableFuture<Void> registerScript(String name, Executable executable,
        boolean allowAnonymousUser, boolean allowAnonymousApp);
CompletableFuture<Void> registerScript(String name, Condition condition, Executable executable,
        boolean allowAnonymousUser, boolean allowAnonymousApp);

Unregister Script

Remove the script with the specified name, after which the script will no longer be executable.

CompletableFuture<Void> unregisterScript(String name);

ScriptRunner

According to the description of Scripting Service, if the data visitor needs to execute scripts, the scripts can only be executed through Script Runner. An example of execution scripts corresponding to the above registered scripts is as follows:

ScriptRunner scriptRunner = new ScriptRunner(callerContext, getVaultProviderAddress());
ObjectNode params = JsonNodeFactory.instance.objectNode();
params.put("author", "John");
params.put("content", "message");
scriptRunner.callScript(ScriptConst.SCRIPT_NAME, params, userDid, appDid, JsonNode.class)
    .thenAcceptAsync(result -> {
            System.out.println("Successfully get the result.");
        }).exceptionally(ex -> {
            ex.printStackTrace();
            return null;
        });

The parameters of Script Runner are the same as the ones used when creating the Vault, and the user DID that is provided belongs to the visitor of the data. During the execution of the script, the parameters of the script template need to be set, and the controller of the script needs to be specified. Then the script is executed by name and the data is manipulated.

Run Script

Executing script operation is just like the above example, besides providing the necessary parameter values, you also need to specify the return value type (resultType）.

<T> CompletableFuture<T> callScript(String name, JsonNode params,
        String targetDid, String targetAppDid, Class<T> resultType);

Upload File

There are eight script types when registering scripts. One more step is needed for two situations: uploading and downloading files. When executing the uploading file script, the transaction ID will be returned first, and then the upload interface will be called to upload the file to the Vault corresponding to the script. At this point, the resultType is the return value of the upload type script execution.

<T> CompletableFuture<T> uploadFile(String transactionId, Class<T> resultType);

Download File

The operation process of downloading a file is similar to that of uploading a file, and the content of the specified file is downloaded through the transaction ID.

<T> CompletableFuture<T> downloadFile(String transactionId, Class<T> resultType);