UiSpec Server

The UiSpec server is a companion application for the Component Server. It provides a client to the Component Server which serves UiSpec payload to integrate with the client JavaScript UiForm library.

Coordinates

<dependency>
  <groupId>org.talend.sdk.component</groupId>
  <artifactId>component-server-proxy</artifactId>
  <version>${server-proxy.version}</version>
</dependency>

Configuring the UiSpec server

the configuration is read from system properties, environment variables, …​. If you use playx-microprofile-config, you can also use typesafe configuration.
talend.component.proxy.actions.proposable.cached

Default value: true. If true the proposable (suggestion lists only depending on the server state) will be cached, otherwise they will be requested for each form rendering.

talend.component.proxy.application.home

Default value: ${playx.application.home}. A home location for relative path resolution (optional).

talend.component.proxy.client.executor.threads

Default value: 64. For the client executor, the number of threads.

talend.component.proxy.client.providers

List of JAX-RS providers to register on the client, at least a JSON-B one should be here.

talend.component.proxy.client.timeouts.connect

Default value: 60000. The connect timeout for the communication with the server.base in ms.

talend.component.proxy.client.timeouts.read

Default value: 600000. The read timeout for the communication with the server.base in ms.

talend.component.proxy.jcache.active

Default value: true. Should the server use jcache to store catalog information and refresh it with some polling. If so the keys talend.component.proxy.jcache.caches.$cacheName.expiry.duration, talend.component.proxy.jcache.caches.$cacheName.management.active and talend.component.proxy.jcache.caches.$cacheName.statistics.active will be read to create a JCache MutableConfiguration. Also note that if all the cachesshare the same configuration you can ignore the $cacheName layer.

talend.component.proxy.jcache.cache-key.name

A header to use in the cache key (to represent a tenant or equivalent).

talend.component.proxy.jcache.provider

Caching provider implementation to use (only set it if ambiguous).

talend.component.proxy.jcache.refresh.period

Default value: 60. Number of seconds used to check if the server must be refreshed.

talend.component.proxy.processing.headers

The headers to append to the request when contacting the server. Format is a properties one. You can put a hardcoded value or a placeholder (${key}).In this case it will be read from the request attributes and headers.

talend.component.proxy.processing.uiSpec.patch

Default value: component-uispec-metadata.%s.json?force=false. An optional location (absolute or resolved from APP_HOME environment variable). It can take an optional query parameter force which specifies if the startup should fail if the file is not resolved. The resolution is done per configuration type (datastore, dataset, …​) but fallbacks on default type if the file is not found.

The values can be keys in the resource bundle org.talend.sdk.component.proxy.enrichment.i18n.Messages. Use that for display names, placeholders etc…​The content talend.component.proxy.server.base:: The base to contact the remote server (NOTE: it is recommanded to put a load balancer if you have multiple instances.)

Adding custom entries to the forms

As shown in the table above, you can customize the forms by type. The format reuses Talend Component Kit HTTP API (properties model) and defines two main types of extensions:

  1. prependProperties: Lists all the models of properties added to the form before the actual underlying form.

  2. appendProperties: Lists all the models of properties added to the form after the actual underlying form.

If you don’t specify a name, the path is used to deduce the name automatically.

Always make sure to define a root object for these properties. Do not use dots in the path value. It is recommended to prefix it with a $ character.

Adding custom converters (selecting the widget or rendering)

When developing a org.talend.sdk.component.form.internal.converter.CustomPropertyConverter CDI, the proxy adds it to the UiSpecService service and uses it with a high priority to convert the server model to a UiSpec model.

To make it a CDI bean, add @Dependent to the class and if you use the Play integration, customize the bean array: playx.cdi.beans.customs += {className: org.talend.myapp.MyConverter}.

This allows to use a custom @Ui API and advanced modeling when specific to applications.
Converters are sorted respecting to the @Priority value. If the annotation is missing, the priority defaults to 0.

Enabling help/hints

It is possible to show the help about each property under the inputs. To do that, you must set a PropertyContext.Configuration instance on UiSpecService with the includeDocumentationMetadata attribute set to true.

This feature is only available with default content of the @Documentation annotation of a property. This means that hints are only available in the default language of the component.

Client in Play

The client to use to connect to the Talend Component Kit server is the CXF client, using HttpClient HC (NIO) transport. When you use the Play module, it can be configured with its standard properties prefixed by talend.component.proxy..

You can find more information on CXF website.

Defining a dropdown with all root configurations

The special dynamic_values action builtin::roots can be used for a dropdown filled with all available root types.

Here is a sample patch file:

{
  "prependProperties": [
    {
      "path": "$datasetMetadata",
      "type": "OBJECT"
    },
    {
      "path": "$datasetMetadata.type",
      "displayName": "Types",
      "type": "ENUM",
      "metadata": {
        "action::dynamic_values": "builtin::roots"
      }
    }
  ]
}

Populate a dropdown from a remote call

In some cases you will want to call a remote service giving you a list of data. For that there is a specific http builtin trigger which will be caught on the proxy and redirected to the configured server to map it as a dynamic_values trigger.

Assume you want to call http:://foo.com/bar propagating the cookies to get the proposals for the entry bar, then you will configure it this way:

{
  "prependProperties": [
    {
      "path": "$datasetMetadata",
      "type": "OBJECT"
    },
    {
      "path": "$datasetMetadata.bar",
      "displayName": "Bar",
      "type": "STRING",
      "metadata": {
        "action::dynamic_values": "builtin::http::dynamic_values(url=http:://foo.com/bar,headers=cookie)"
      }
    }
  ]
}

The configuration of the call is passed through a comma separated list in parenthesis as seen in previous snippet. The configuration entries are the following ones:

Name Description Sample

url

The target server to call. Note that placeholder are supported and filled from request headers (placeholderProvider).

proposals.service.com

headers

; separated list of headers to propagate (using placeholderProvider).

cookie,Authorization

accept

The Accept header. Note that current we only support to parse JSON output and it defaults to application/json.

application/v1+json

object

Boolean (default to false) to set to true if the response payload is an object and not a list.

true

objectKey

If object is true, the key to extract to get the list to process.

items

id

Name of the field to extract from an item of the response list to map to the identifier of the proposal (default to id).

id

name

Name of the field to extract from an item of the response list to map to the label of the proposal (default to name).

label

Populate a dropdown with a list of references

In some forms you will want to populate a dropdown with a list of entities available in your database. For that, the proxy will rely on a SPI called Integration. If you don’t implement it, it uses a Guice integration if Guice is in the classpath or a native CDI integration otherwise.

The integration will then let the proxy lookup a ReferenceService implementation which will provide from a configuration type type and name (for instance datastore, MyDataBaseConfig) the list of references you want to propose to the end user.

Here is very simple implementation:

@ApplicationScoped
public class ReferenceServiceImpl implements ReferenceService {
    @Inject
    private Database db;

    @Override
    public CompletionStage<Values> findReferencesByTypeAndName(final String type, final String name) {
        return CompletableFuture.completedFuture(new Values(db.findByTypeAndName(type, name).stream()
            .map(it -> new Values.Item(it.getId(), it.getName()))
            .collect(toList())));
    }

    @Override
    public CompletionStage<Form> findPropertiesById(final String id) {
        final Entity entity = db.findById(id);
        return CompletableFuture.completedFuture(Form.builder().properties(entity.getProperties()).formId(entity.getFormId()).build());
    }
}

Generally this kind of completion will be activated under the hood by the proxy using this kind of metadata:

{
  "action::dynamic_values": "builtin::references(type=xxxx,name=yyyy)"
}

Going further: make this field hidden when empty

In some cases you will want to hide this field if the proposals are ⇐ 1, in this case you can use a condition:

{
  "prependProperties": [
    {
      "path": "$datasetMetadata",
      "type": "OBJECT"
    },
    {
      "path": "$datasetMetadata.bar",
      "displayName": "Bar",
      "type": "STRING",
      "metadata": {
        "action::dynamic_values": "builtin::http::dynamic_values(url=http:://foo.com/bar,headers=cookie)",
        "condition::if::target": ".",
        "condition::if::value": "0,1",
        "condition::if::negate": "true",
        "condition::if::evaluationStrategy": "LENGTH",
      }
    }
  ]
}

Reloading the form based on the selected root

The builtin::root::reloadFromId action, with the reloadForm type, allows to reload the whole form:

{
  "path": "$datasetMetadata.type",
  "displayName": "Types",
  "type": "STRING",
  "metadata": {
    "action::dynamic_values": "builtin::roots", (1)
    "action::reloadForm": "builtin::root::reloadFromId", (2)
    "action::reloadForm::parameters": "."
  }
}
1 Prepopulating the dropdown with the list of datastores.
2 On selection of a datastore, refreshing the form with the new parameters.

It is common to have a dropdown with the list of roots and to reload the form when one is selected.

The client side (javascript) is now fully encapsulated in ComponentForm from @talend/ui.

Reloading the form based on a selected entity reference

The builtin::root::reloadFromParentEntityId action, with the reloadFromParentEntityId type, allows to reload the whole form:

{
  "path": "$datasetMetadata.reference",
  "displayName": "Reference",
  "type": "STRING",
  "metadata": {
    "action::reloadFromParentEntityId": "builtin::root::reloadFromParentEntityId",
    "action::reloadFromParentEntityId::parameters": "."
  }
}
references are automatically initialized if you use PropertiesService#filterProperties.

HTTP API

Component UiSpec Server

Overview

These endpoints allow to obtain UiSpec representations of the component/configuration types properties.

Version information

Version : v1

Contact information

Contact : Talend
Contact Email : contact@talend.com

License information

License : Apache 2.0
License URL : www.apache.org/licenses/LICENSE-2.0.html
Terms of service : null

URI scheme

Host : host:port
BasePath : /componentproxy/api/v1
Schemes : HTTP, HTTPS

Tags

  • action

  • configuration

  • configurations

  • dataset

  • datastore

  • form

  • icon

  • persistence

  • ui spec

  • uispec

Paths

This endpoint execute an action required by a form.
POST /actions/execute
Description

configuration types has action that can be executed using this endpoint

Parameters
Type Name Schema

Query

action
optional

string

Query

family
optional

string

Query

language
optional

string

Query

type
optional

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

< string, CompletionStageMapStringObject > map

400

This response is returned when the action is null

ProxyErrorPayload

404

This response is returned when no action is found

ProxyErrorPayload

520

This response is returned when the action raise an unhandled error

ProxyErrorPayload
Consumes

  • application/json

Produces

  • application/json

Tags

  • action

  • configurations

Return all the available root configuration (Data store like) from the component server
GET /configurations
Description

Every configuration has an icon. In the response an icon key is returned. this icon key can be one of the bundled icons or a custom one. The consumer of this endpoint will need to check if the icon key is in the icons bundle otherwise the icon need to be gathered using the familyId from this endpoint configurations/{id}/icon

Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

Nodes
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • datastore

Return a form description ( Ui Spec ) without a specific configuration
GET /configurations/form/initial/{type}
Parameters
Type Name Schema

Path

type
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

Nodes
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • dataset

  • datastore

  • form

  • ui spec

Return a form description ( Ui Spec ) of a specific configuration
GET /configurations/form/{id}
Parameters
Type Name Schema

Path

id
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

UiNode
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • dataset

  • datastore

  • form

  • ui spec

Return the configuration icon file in png format
GET /configurations/icon/{id}
Parameters
Type Name Schema

Path

id
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

CompletionStageByte[]
Consumes

  • application/json

Produces

  • application/json

  • application/octet-stream

Tags

  • icon

Update a configuration.
POST /configurations/persistence/edit/{id}
Parameters
Type Name Schema

Path

id
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

EntityRef
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • dataset

  • datastore

  • form

  • persistence

  • ui spec

Saves a configuration based on a type. Concretely it is the same as /persistence/save/{formId} but the formId is contained into the payload itself and marked in the metadata as such.
POST /configurations/persistence/save-from-type/{type}
Parameters
Type Name Schema

Path

type
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

EntityRef
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • dataset

  • datastore

  • form

  • persistence

  • ui spec

Saves a configuration based on a form identifier.
POST /configurations/persistence/save/{formId}
Parameters
Type Name Schema

Path

formId
required

string
Responses
HTTP Code Description Schema

200

successful operation
Headers :
Talend-Component-Server-Error (boolean) : This header indicate the error origin. true indicate an error from the component server, false indicate that the error is from this proxy.

EntityRef
Consumes

  • application/json

Produces

  • application/json

Tags

  • configurations

  • dataset

  • datastore

  • form

  • persistence

  • ui spec

Definitions

CompletionStage

Type : object

CompletionStageByte[]

Type : object

CompletionStageCollectionSimplePropertyDefinition

Type : object

CompletionStageMapStringObject

Type : object

CompletionStageMapStringString

Type : object

CompletionStageNodes

Type : object

EntityRef
Name Description Schema

id
optional

The identifier of the entity related to current request. It is generally thecreated entity of updated one.

string
JsonSchema
Name Schema

defaultValue
optional

object

description
optional

string

enumValues
optional

< string > array

id
optional

string

items
optional

JsonSchema

maxItems
optional

integer (int32)

maxLength
optional

integer (int32)

maximum
optional

number (double)

minItems
optional

integer (int32)

minLength
optional

integer (int32)

minimum
optional

number (double)

pattern
optional

string

properties
optional

< string, JsonSchema > map

ref
optional

string

required
optional

< string > array

schema
optional

string

title
optional

string

type
optional

string

uniqueItems
optional

boolean
NameValue
Name Schema

name
optional

string

value
optional

string
Node
Name Description Schema

children
optional

The list of configuration reusing this one as a reference (can be created "next").

< string > array

familyId
optional

The identifier of the family of this configuration.

string

familyLabel
optional

The display name of the family of this configuration.

string

icon
optional

The icon of this configuration. If you use an existing bundle (@talend/ui/icon), ensure it is present by default and if not do a request using the family on the related endpoint.

string

id
optional

The identifier of this configuration/node.

string

label
optional

The display name of this configuration.

string

name
optional

The technical name of this node (it is human readable but not i18n friendly), useful for debug purposes.

string

version
optional

The version of this configuration for the migration management.

integer (int32)
Nodes
Name Description Schema

nodes
optional

The list of nodes matching the request. The key is the node identifier.

< string, Node > map
Option
Name Schema

path
optional

string

type
optional

string
Parameter
Name Schema

key
optional

string

path
optional

string
ProxyErrorPayload
Name Description Schema

code
optional

The error code independently of the locale and not as precise as a message (not context aware).

string

message
optional

A human readable message to help understanding the error

string
Trigger
Name Schema

action
optional

string

family
optional

string

onEvent
optional

string

options
optional

< Option > array

parameters
optional

< Parameter > array

type
optional

string
Ui
Name Schema

jsonSchema
optional

JsonSchema

properties
optional

object

uiSchema
optional

< UiSchema > array
UiNode
Name Description Schema

metadata
optional

The metadata associated to the node if needed by the UI.

Node

ui
optional

The ui specification corresponding to the requested node. It is literally the form representing this configuration.

Ui
UiSchema
Name Schema

autoFocus
optional

boolean

condition
optional

< string, < object > array > map

description
optional

string

disabled
optional

boolean

itemWidget
optional

string

items
optional

< UiSchema > array

key
optional

string

options
optional

< string, string > map

placeholder
optional

string

readOnly
optional

boolean

required
optional

boolean

restricted
optional

boolean

title
optional

string

titleMap
optional

< NameValue > array

triggers
optional

< Trigger > array

type
optional

string

widget
optional

string

There are two ways to call the save endpoint. If you don’t want to pass the form identifier and prefer to use a generic endpoint that simply passes the type of configuration you are configuring, then you need to modify your enrichment configuration to ensure that the form identifier is present and to specify which form field it is.

To do that, add the proxyserver::formId Boolean to the metadata:

{
  "path": "$datasetMetadata.type",
  "displayName": "Types",
  "type": "STRING",
  "metadata": {
    // other metadata as seen previously
    "proxyserver::formId": "true"
  }
}
Only the first property with proxyserver::formId set to "true" is used. The path cannot contain any array.

Configuring the server module

The server module contains several configurations that you can set in:

  • Environment variables.

  • System properties.

  • A file located based on the --component-configuration CLI option.

the configuration is read from system properties, environment variables, …​.
talend.component.server.component.coordinates

A comma separated list of gav to locate the components

talend.component.server.component.extend.dependencies

Default value: true. Should the component extensions add required dependencies.

talend.component.server.component.registry

A property file where the value is a gav of a component to register (complementary with coordinates)

talend.component.server.documentation.active

Default value: true. Should the /documentation endpoint be activated.

talend.component.server.execution.dataset.retriever.timeout

Default value: 180. How long the read execution endpoint can last (max)

talend.component.server.execution.pool.wait

Default value: PT10S. How long the application waits during shutdown for the execution tasks to complete

talend.component.server.jaxrs.exceptionhandler.defaultMessage

Default value: false. If set it will replace any message for exceptions. Set to false to use the actual exception message.

talend.component.server.maven.repository

The local maven repository used to locate components and their dependencies

talend.component.server.metrics.active

Default value: true. Should the /api/v1/metrics endpoint be activated.

talend.component.server.monitoring.brave.service.name

Default value: component-server. The name used by the brave integration (zipkin)

talend.component.server.security.command.handler

Default value: securityNoopHandler. How to validate a command/request. Accepted values: securityNoopHandler.

talend.component.server.security.connection.handler

Default value: securityNoopHandler. How to validate a connection. Accepted values: securityNoopHandler.

Services

The module provides some services usable to fulfill some basic requirements of the component interaction:

  • ConfigurationFormatter to (un)flatten the properties (JSON from/to key-value format)

  • ConfigurationVisitorService to browse properties and identify credentials to cipher them

  • ValidationService to validate a JSON properties set before any persistence action

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