Database

Service URI - luna://com.palm.db

Enables apps to store persistent data.

 

DB8 is an API for managing embedded JSON database. DB8 allows apps to store persistent data. DB8 provides various functions that allow entry, storage and retrieval of large quantities of information as well as provides ways to manage how that information is organized.

 

It provides the following data management functions:

• Add objects
• Update objects
• Delete objects
• Query objects
• Manage access to objects within the database

 

To learn about webOS Database (DB8) service and how to use it, see Database (DB8).

Methods

Method	Description	Supported in Emulator
batch	Enables apps to execute multiple database operations in one service request.	Yes
del	Deletes the JSON data objects from the database.	Yes
delKind	Deletes a kind from the database.	Yes
find	Returns a set of objects that match the query specified in the query parameter.	Yes
get	Retrieves JSON data objects by IDs.	Yes
merge	Updates the object properties in existing objects.	Yes
put	Stores JSON data objects of a particular kind into the database.	Yes
putKind	Registers a kind with the database.	Yes
putPermissions	Enables other apps or services to access the apps stored DB8 data.	Yes
reserveIds	Reserves a block of objects IDs.	Yes
search	Supports the ? operator which is used for full-text searching.	Yes
watch	Watches for updates to the database that would change the results of a query.	Yes

 

Open All

batch

Description

Enables apps to execute multiple database operations in one service request. It allows only the following database operations:

• put
• get
• del
• find (without a watch)
• merge 

 

Atomicity is NOT guaranteed across batched operations.

Syntax

batch(Object[] operations)

Parameters

Name	Required	Type	Description
operations	Required	Object array	The list of database operations to perform.

Call Returns

Name	Required	Type	Description
BatchResponse	Optional	Object	If the method succeeds, it will return the BatchResponse object.
ErrResponse	Optional	Object	If the method fails, it will return the ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3984	No required key: "method"	The required database operations name is missing.
-3984	No required key: "params"	The required parameters for a database operation is missing.
-3982	db: invalid operation in batch	An incorrect or an unsupported database operation was specified in the operations parameter.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "batch",
	parameters: {
		"operations":[
			{
				"method":"put",
				"params":{
					"objects":[
						{
							"_kind":"com.yourdomain.test:1",
							"sample":"sample1",
							"test":"test1"
						}
					]
				}
			},
			{
				"method":"merge",
				"params":{
					"query":{
						"from":"com.yourdomain.test:1",
						"where":[
							{
								"prop":"sample",
								"op":"=",
								"val":"sample1"
							}
						]
					},
					"props":{
						"sample":"sample2",
						"test": "test2"
					}
				}
			}
		]
	},
	onSuccess: function (inResponse) {
		console.log("The batch work is excuted");
		console.log(JSON.stringify(inResponse);
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to execute the batch work");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "responses": [
        {
            "returnValue": true,
            "results": [
                {
                    "id": "JHd3Dg427oB",
                    "rev": 21868
                }
            ]
        },
        {
            "count": 1,
            "returnValue": true
        }
    ],
    "returnValue": true
}

See Also

• del

del

Description

Deletes the JSON data objects from the database.
Apps can specify the objects as:

• A set of IDs
• A DB8 query

Syntax

del([String[] ids][, Object query][, Boolean purge])

Parameters

Name	Required	Type	Description
ids	Optional	String array	An array of JSON object ids that you wish to delete. If you do not wish to specify JSON object ids, you must specify a query of in the query parameter.
query	Optional	Object	A query for a set of objects to be deleted. If you do not wish to specify a query, you must specify a list of JSON object ids in the ids parameter.
purge	Optional	Boolean	The default value is false. false: The target objects will only be marked for deletion. Objects marked for deletion can still be restored. They will be purged permanently only when an administrative purge operation is run. true: The target objects will be deleted permanently immediately.

Call Returns

Name	Required	Type	Description
PutResponse	Optional	Object	When the method succeeds, and the objects to be deleted were specified as a list of JSON object ids, it will return a PutResponse object.
CountResponse	Optional	Object	When the method succeeds, and the objects to be deleted were specified as a query, it will return a CountResponse object
ErrResponse	Optional	Object	If the method fails, it will return the ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3963	db: permission denied	The app does not have permission to delete the specified object.
-3965	db: no index for query	The query is referring to an index that does not exist for the specified kind.
-3962	db: quota exceeded	There is no space left on the device to complete this operation. It is recommended that the app should call the method again with purge set to true.

Example

// Delete data with ID
var request = webOS.service.request("luna://com.palm.db", {
	method: "del",
	parameters: {
		"ids" :["JHd3Dg427oB"]
	},
	onSuccess: function (inResponse) {
		console.log("The " + inResponse.results.id "object is deleted");
		// To-Do something
		}
	},
	onFailure: function (inError) {
		console.log("Failed to delete the obejct");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

// Delete data with query
// Delete all data object from com.yourdomain.test:1 kind
var request = webOS.service.request("luna://com.palm.db", {
	method: "del",
	parameters: {
                "query" : { 
                        "from" : "com.yourdomain.test:1"
                }
        },
	onSuccess: function (inResponse) {
		console.log("The " + inResponse.count "object(s) is(are) deleted");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to delete the obejct");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

// Result: Delete with ID 
{
    "returnValue": true,
    "results": [
        {
            "id": "J8rBI6u7uh+"
        }
    ]
}

// Result: Delete with Query
{
    "count": 11,
    "returnValue": true
}

See Also

• delKind

• put

delKind

Description

Deletes a kind from the database. Deleting a kind deletes ALL data objects of that kind.

Syntax

delKind(String id)

Parameters

Name	Required	Type	Description
id	Required	String	The id of kind the app wants to delete.

Call Returns

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
errorCode	Optional	Number	errorCode contains the error code if the method fails. The method will return errorCode only if it fails. See the Error Codes Reference of this method for more details.
errorText	Optional	String	errorText contains the error text if the method fails. The method will return errorText only if it fails. See the Error Codes Reference of this method for more details.

Error Reference

Error Code	Error Message	Error Description
-3970	db: kind not registered	The specified kind doesn't exist in the database.
-3999	db: access denied	The specified kind exists in the database, however the app does not have the delete permissions.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "delKind",
	parameters: {
		"id": "com.yourdomain.test:1"
	},
	onSuccess: function (inResponse) {
		console.log("The kind is deleted");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to delete the kind");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

See Also

• del

• putKind

find

Description

Returns a set of objects that match the query specified in the query parameter.

 

The app can specify the number of results to return. However, if the app does not want to specify a limit, it can set the count parameter to true. This will cause the find method to return the total number of results returned in the FindResponse object.

The app can also request to be notified if any of the returned results from the query change in the future. In order to receive change notifications, set the watch parameter to true.

 

The find method supports group by(distinct) enabling the app to remove duplicate objects. 

Syntax

find(Object query[, Boolean count][, Boolean watch])

Parameters

Name	Required	Type	Description
query	Required	Object	DB8 query for retrieving results.
count	Optional	Boolean	The default value of the count parameter is false. If the app did not specify a limit on the number of results to return, and wants to know the total number of results returned, the app should set the count parameter to true.
watch	Optional	Boolean	The default value of the watch parameter is false.  If an app wants to be notified about any change in the returned results, the app should set the watch parameter to true.

Call Returns

Name	Required	Type	Description
FindResponse	Optional	Object	If the find method succeeds, the find method will return the FindResponse​ object.
NotificationResponse	Optional	Object	If the watch parameter was set to true by the app, the find method will return the NotificationResponse object.
ErrResponse	Optional	Object	If the find method fails, it will return the ErrResponse​ object.

Error Reference

Error Code	Error Message	Error Description
-3970	db: kind not registered	The specified kind is not registered in the database.
-3978	db: invalid query	The query syntax is correct, but contains misspelled commands or logical errors.
-3965	db: no index for query	The SELECT query contains field name(s) that do not exist for the selected kind.
-3963	db: permission denied	The specified kind exists in the database, however the app does not have permissions to read the data for the specified kind.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "find",
	parameters: { 
		"query": {
			"from": "com.yourdomain.test:1",
			"where": [ 
				{ "prop":"sample", "op":"=", "val":"sample1"	} 
			]
		}
	},
	onSuccess: function (inResponse) {
		console.log( inResponse.results.length() + " object(s) is(are) found");
		console.log( "Result: " + JSON.stringify(inResponse) );
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to find the obejct with query");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "returnValue": true,
    "results": [
        {
            "_rev": 21873,
            "sample": "sample2",
            "test": "test2",
            "_id": "JHdxo18aqjZ",
            "_kind": "com.yourdomain.test:1"
        },
        {
            "_rev": 21875,
            "sample": "sample2",
            "test": "test2",
            "_id": "JHdyO1clmYs",
            "_kind": "com.yourdomain.test:1"
        }
    ]
}

See Also

• get
• search

get

Description

Retrieves JSON data objects by ids. This is the fastest way to retrieve data.

Syntax

get(String[] ids)

Parameters

Name	Required	Type	Description
ids	Required	String array	Ids of the JSON data objects to retrieve.

Call Returns

Name	Required	Type	Description
GetResponse	Optional	Object	If the method succeeds, it will return the GetResponse​ object.
ErrResponse	Optional	Object	If the method fails, it will return the ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3999	db: access denied	The specified object exists in the database, but the app does not have permissions to access the object.
-3950	db: I/O error	It is not possible to read from the database and that this is a critical error.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "get",
	parameters: { 
		"ids" : ["J8rKTaBClIo"]
	},
	onSuccess: function (inResponse) {
		console.log( inResponse.results.length() + " object(s) is(are) retrieved");
		console.log( "Result: " + JSON.stringify(inResponse) );
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to get the obejct(s)");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "returnValue": true,
    "results": [
        {
            "_rev": 21,
            "sample": "sample1",
            "test": "test1",
            "_id": "J8rKTaBClIo",
            "_kind": "com.yourdomain.test:1"
        }
    ]
}

See Also

• find

• search

merge

Description

Updates the object properties in existing objects.

The objects can be specified in one of the following ways.

• A query
• An array of IDs

 

Objects can be specified using a query (returns CountResponse) or array of IDs (returns PutResponse).

Syntax

merge([Object[] objects][, Object query][, Object props])

Parameters

Name	Required	Type	Description
objects	Optional	Object array	The objects parameter is an array of objects, each object will have an id and key/value pairs that represents the object properties the app needs to merge. The objects parameter is required if the query​ parameter is not specified.
query	Optional	Object	Query object specifying the set of object whose properties the app wants to update. The query parameter is required if the objects parameter is not specified.
props	Optional	Object	The props parameter is an object with key/value pairs that specify the set of properties to be merged into the existing object(s) specified in the query parameter. If the app specifies the properties in the prop parameter, the query​ is required.

Call Returns

Name	Required	Type	Description
PutResponse	Optional	Object	If the objects parameter was specified, and the method succeeds, it will return the PutResponse object.
CountResponse	Optional	Object	If the parameter was specified, and the merge method succeeds, it will return the CountResponse ​object.
ErrResponse	Optional	Object	If the method fails, it will return the ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3961	db: quota exceeded	The app has exceeded its quota or there no free space is available on the device.
-3963	db: permission denied	The app does not have permission to modify the specified objects.
-3965	db: no index for query	The query contains a SELECT for object properties that do not have an index associated with them.

Example

// Update object with ids and values
var request = webOS.service.request("luna://com.palm.db", {
	method: "merge",
	parameters: { 
		"objects" : [
			{
				"_id":"J8rKTaBClIo",
				"test":"test1",
				"sample":"sample_updated_value"
			}
		]
	},
	onSuccess: function (inResponse) {
		console.log( "The object(s) is(are) updated");
		console.log( "Result: " + JSON.stringify(inResponse) );
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to update the obejct(s)");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

// Update data with query
var request = webOS.service.request("luna://com.palm.db", {
	method: "merge",
	parameters: { 
		"query":{
			"from":"com.yourdomain.test:1",
			"where":[
				{
					"prop":"sample",
					"op":"=",
					"val":"sample1"
				}
			]
		},
		"props":{
			"sample":"sample_updated_value"
		}
	},
	onSuccess: function (inResponse) {
		console.log( inResponse.count + " object(s) is(are) updated");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to update the obejct(s)");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

// Return: Update object with ids and values
{
    "returnValue": true,
    "results": [
        {
            "id": "J8rKTaBClIo",
            "rev": 23
        }
    ]
}

// Return: Update data with query
{
    "count": 2,
    "returnValue": true
}

See Also

• del

• put

• watch

put

Description

Stores JSON data objects of a particular kind into the database. The put method will:

• Assign an id field to each object, if it was not set
• Return the id and rev for each stored object

Syntax

put(Object[] objects)

Parameters

Name	Required	Type	Description
objects	Required	Object array	List of JSON data objects of a particular kind that the app wants to store in the database.

Call Returns

Name	Required	Type	Description
PutResponse	Optional	Object	If the method succeeds, it will return PutResponse object.
ErrResponse	Optional	Object	If the method fails, it will return ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3962	db: quota exceeded	The app has exceeded its quota or there no free space is available on the device.
-3970	db: kind not registered	The kind for the specified object is not registered with the database.
-3963	db: permission denied	The app does not have permission to save objects of a specified kind.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "put",
	parameters: { 
		"objects":[
        {
            "_kind":"com.yourdomain.test:1",
            "sample":"sample1",
            "test":"test1"
        }
    ]
	},
	onSuccess: function (inResponse) {
		console.log("The object(s) is(are) added");
		console.log("Result: " + JSON.stringify(inResponse));
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to add the obejct(s)");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "returnValue": true,
    "results": [
        {
            "id": "J8rTIa65u++",
            "rev": 27
        }
    ]
}

See Also

• del

• merge

• putKind

putKind

Description

Registers a kind with the database.

Kinds define the owner, and the indexes for a JSON data object. Indexes can be composed of single or multiple properties. When you create your index, be aware that queries can only return results that are indexed, and are contiguously ordered.

If your app or service wants to be notified only when a subset of an object's properties are updated, then you can use revision sets.

If your app or service creates objects that other apps or services need to access, then see the putPermissions method for more information.

Syntax

putKind(String id, String owner[, Object schema][, Boolean sync][, String[] extends][, Object indexes][, Object[] revsets])

Parameters

Name	Required	Type	Description
id	Required	String	Id of the kind.
owner	Required	String	Onwer of the kind. Possible values: The service's bus address, or The app's app ID Only the owner has permission to modify the kind.
schema	Optional	Object	JSON Syntax for data objects of a specific kind. If set, this kind's data objects are validated before being stored. For details refer to http://www.json.org/.
sync	Optional	Boolean	Enables apps to enable backing up and restoring specific kinds of objects.  The default value for the parameter is false. If the app wants to enable backing up and restoring objects to LG servers on a daily basis, the app should set sync to true.  If the user moves to another device, the saved app data can be restored.
extends	Optional	String array	List of the ids of kind parents.
indexes	Optional	Object	The kind indexes.
revsets	Optional	Object array	List of database revision sets.

Call Returns

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
errorCode	Optional	Number	errorCode contains the error code if the method fails. The method will return errorCode only if it fails. See the Error Codes Reference of this method for more details.
errorText	Optional	String	errorText contains the error text if the method fails. The method will return errorText only if it fails. See the Error Codes Reference of this method for more details.

Error Reference

Error Code	Error Message	Error Description
-3981	db: invalid owner for kind	The specified owner does not have permissions to add or modify the specified kind.
-3962	db: quota exceeded	App has exceeded its quota or does not have enough disk space available to create the specified kind.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "putKind",
	parameters: { 
		"id": "com.yourdomain.test:1",
		"owner":"com.yourdomain.test",
		"indexes":[
			{ 
				"name":"sample",
				"props":[ {"name":"sample"} ]
			},
			{
				"name":"testsample",
				"props":[ {"name":"test"}, {"name":"sample"}]
			} 
		]
	},
	onSuccess: function (inResponse) {
		console.log("The kind is created");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to create the kind");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

See Also

• put
• putPermissions

putPermissions

Description

Enables other apps or services to access the apps stored DB8 data. The app can give permissions to access data objects of a particular kind.

Syntax

putPermissions(String type, String object, String caller, Object operations[, String create][, String read][, String update][, String delete])

Parameters

Name	Required	Type	Description
type	Required	String	Must be set to db.kind.
object	Required	String	The DB8 kind of the object for which the app wants to provide access.
caller	Required	String	The id of the app or service that the app is granting permission to access its data.
operations	Required	Object	Database operations the app is granting permissions for.
create	Optional	String	To grant create permission, set the create parameter to allow.
read	Optional	String	To grant read permission, set the read parameter to allow.
update	Optional	String	To grant update permission, set the update parameter to allow.
delete	Optional	String	To grant delete permission, set the delete parameter to allow.

Call Returns

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
errorCode	Optional	Number	errorCode contains the error code if the method fails. The method will return errorCode only if it fails. See the Error Codes Reference of this method for more details.
errorText	Optional	String	errorText contains the error text if the method fails. The method will return errorText only if it fails. See the Error Codes Reference of this method for more details.

Error Reference

Error Code	Error Message	Error Description
-3999	db: access denied	The app cannot modify the permissions of the specified kind

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "putPermissions",
	parameters: { 
		"permissions":[
			{
				"operations":{
					"read":"allow",
					"create":"allow",
					"update":"allow",
					"delete":"allow"
				},
				"object":"com.yourdomain.test:1",
				"type":"db.kind",
				"caller":"com.yourdomain.testapp"
			}
		]
	},
	onSuccess: function (inResponse) {
		console.log("The permission(s) is(are) set");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to set the permission(s)");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

See Also

• putKind

reserveIds

Description

Reserves a block of object ids.

Syntax

reserveIds(Number count)

Parameters

Name	Required	Type	Description
count	Required	Number	Number of Ids to reserve.

Call Returns

Name	Required	Type	Description
ReserveIdsResponse	Optional	Object	If the method succeeds it will return ReserveIdsResponse object.
ErrResponse	Optional	Object	If the method fails, it will return ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3968	db: malformed id	The specified count contains invalid value.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "reserveIds",
	parameters: { 
		"count": 3
	},
	onSuccess: function (inResponse) {
		console.log(inResponse.ids.length() + " object ID(s) is(are) reserved");
		console.log("Result: " + JSON.stringify(inResponse) );
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to reserve object IDs");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "ids": [
        "J9FJ12j0Usk",
        "J9FJ12j18hJ",
        "J9FJ12j1Mic"
    ],
    "returnValue": true
}

See Also

• del

• get

• merge

• put

search

Description

Supports the ? operator. The ​?  operator can be used for full-text searching. However, the search method is significantly slower, and should only be used for full-text type-down search. The search method should not be used for retrieving results that are going to be scrolled in a list.

The search method supports:

• Ordering by any property
• Distinct method to remove duplicate objects
• %% operator in filter to search in a substring

 

The search method has some limitations:

• There must be an index for the field you are searching on
• The search operation looks for words beginning with the search string.

Syntax

search(Object query[, Boolean watch])

Parameters

Name	Required	Type	Description
query	Required	Object	Query for search.
watch	Optional	Boolean	The default value of the watch parameter is false. If the app wants to be notified of any changes in the search results, it should set the watch parameter to true​.

Call Returns

Name	Required	Type	Description
FindResponse	Optional	Object	If the method succeeds, it will return the FindResponse object.
NotificationResponse	Optional	Object	If the method succeeds and the app had set the watch parameter to true, search will return the NotificationResponse  object.
ErrResponse	Optional	Object	If the method fails, it will return a ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3987	db: invalid filter op	An invalid operation was specified in the filter.
-3978	db: invalid query	There was a syntax error in the query.
-3977	db: collations on property do not match	The collation sequence of a property  across different objects do not match.
-3975	db: invalid combination of query operations	The query syntax is correct, but contains logical errors.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "search",
	parameters: { 
		"query":{
			"from":"com.yourdomain.test:1",
			"where":[
				{
					"prop":"sample",
					"op":"?",
					"val":"sample"
				}
			]
		}
	},
	onComplete: function (inResponse) {
		console.log(inResponse.count + " objects is(are) returned.");
		console.log("Results: " + JSON.stringify(inResponse));
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to search");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "count": 4,
    "returnValue": true,
    "results": [
        {
            "_rev": 22,
            "sample": "sample_updated_value",
            "test": "test1",
            "_id": "J8rKQDOvxdF",
            "_kind": "com.yourdomain.test:1"
        },
        {
            "_rev": 23,
            "sample": "sample_updated_value",
            "test": "test1",
            "_id": "J8rKTaBClIo",
            "_kind": "com.yourdomain.test:1"
        },
        {
            "_rev": 26,
            "sample": "sample1",
            "test": "test1",
            "_id": "J8rTH76hfcB",
            "_kind": "com.yourdomain.test:1"
        },
        {
            "_rev": 27,
            "sample": "sample1",
            "test": "test1",
            "_id": "J8rTIa65u++",
            "_kind": "com.yourdomain.test:1"
        }
    ]
}

See Also

• find

• get

watch

Description

Watches for updates to the database that would change the results of a query.

Syntax

watch(Object query)

Parameters

Name	Required	Type	Description
query	Required	Object	Query whose results the app wants to watch.

Call Returns

Name	Required	Type	Description
SuccessResponse	Optional	Object	If DB8 have enough resources to add client into  "watch stack" and the wtch method succeeds, it will return the SuccessResponse ​object.
NotificationResponse	Optional	Object	If DB8 have enough resources to add into "watch stack" and DB8 found some record for query, it will return a NotificationResponse object.
ErrResponse	Optional	Object	If the method fails, it will return ErrResponse object.

Error Reference

Error Code	Error Message	Error Description
-3999	db: access denied	The app does not have permissions to monitor the database.

Example

var request = webOS.service.request("luna://com.palm.db", {
	method: "watch",
	parameters: { 
		"query":{
			"from":"com.yourdomain.test:1",
			"where":[
				{
					"prop":"sample",
					"op":"=",
					"val":"sample1"
				}
			]
		}
	},
	onSuccess: function (inResponse) {
		console.log("The object, which is met specified criteria, was found.");
		// To-Do something
	},
	onFailure: function (inError) {
		console.log("Failed to watch");
		console.log("[" + inError.errorCode + "]: " + inError.errorText);
		// To-Do something
		return;
	}
});

Return Example

{
    "returnValue": true,
    "fired": true
}

See Also

• merge

• put

Object

BatchOperation Object

Object for batch operation.

{
    "method" : string,
    "params" : any
}

Name	Required	Type	Description
method	Required	String	Database operation to perform. Allowed values are: del find get merge put
params	Required	String	List of parameters for the database operation.

BatchResponse Object

Response to batch operation.

{
    "returnValue": boolean,
    "responses"  : any array
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
responses	Required	Array	Array of responses for each of the operations in the batch

ErrResponse Object

Standard error response, containing operation success or failure flag, error code and error message.

{
    "returnValue": boolean,
    "errorCode"  : int,
    "errorText"  : string
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure If the method fails, the method will return error message and error message description in errorCode and errorText fields respectively.
errorCode	Required	Number	Numeric error code.
errorText	Required	String	Error message from the service. This property is available when request fails.

Query Object

Defines a DB8 query.

// Schema

{
      "select"  : string array,
      "from"    : string,
      "where"   : WhereClause array,
      "orderBy" : string,
      "desc"    : boolean,
      "incDel"  : boolean,
      "limit"   : int,
      "page"    : string
}

// Example

{
      "select"  : ["displayName", "state"],
      "from"    : "com.mystuff.contacts:1",
      "where"   : [{"prop":"state","op":"=","val":"CA"}],
      "orderBy" : "displayName",
      "desc"    : true
}

Name	Required	Type	Description
select	Optional	String array	Array of property names to return.
from	Required	String	Name of kind to retrieve results from.
where	Optional	Object array	Array of clauses to test.
orderBy	Optional	String	Order results on this property.
desc	Optional	Boolean	If set to true, query results will be returned in a descending order.
incDel	Optional	Boolean	If incDel is true, the query results will include the deleted object. Note: You can only request this if the incDel field was true when you created your indexes during a putKind operation. Otherwise, the query fails with a "no index for this query" message.
limit	Optional	Number	Specifies maximum number of results to return (0-500). Default is 500.
page	Optional	String	Page key returned by previous query.
filter	Optional	Object array	Array of clauses - works only in the search method - identical to WhereClause. Can be used along with where to perform a range search.

putResponse Object

Indicates success of operation and returns id and rev fields for each object.

{
      "returnValue" : boolean,
      "results"     : PutResult
} 

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
results	Required	Object array	Array of objects containing the id and rev of each object that was put.

countResponse Object

Number of objects affected by operation.

{
      "returnValue" : boolean,
      "count"       : int
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
count	Required	Number	Array of objects containing the id and rev of each object that was put.

FindResponse Object

Response to a find objects operation.

{
      "returnValue" : boolean,
      "results"     : any,
      "count"       : int,
      "next"        : string
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
results	Required	Any	Array of DB8 kind data objects. What is returned depends on the query and what is stored.
count	Optional	Number	Number of results that would have been returned if a limit had not been specified.
next	Optional	String	Key to pass as query's "page" property when retrieving next page of results.

NotificationResponse Object

Notifies caller of change in query results returned from a "find" call.

{
      "returnValue" : boolean,
      "fired"       : boolean
}

Name	Required	Type	Description
returnValue	Optional	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
fired	Required	Boolean	Change notification flag.

GetResponse Object

Parameters for get objects operation response.

{
      "returnValue" : boolean,
      "results"     : any
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
results	Required	Object array	Returns array of stored DB8 data objects.

IndexClause Object

Used in the putKind call for creating kind object indexes. Note that indexes determine the type of queries your app can make. See Queries and Indexing for more information. Set the incDel flag to true if you want future queries to return marked as deleted objects. Objects are not completely deleted until an administrative purge operation takes place.

//Schema
{
      "name"    : string,
      "props"   : IndexPropClause,
      "incDel"  : boolean 
}

//Example

{
      "name"   : "state",
      "props"  : [{"name": "state"}],
      "incDel" : false
}

Name	Required	Type	Description
name	Required	String	Index name
props	Required	Object array	Array of properties to index together.
incDel	Optional	Boolean	If incDel is true, the query results will include the deleted object. Note: You can only request this if the incDel field was true when you created your indexes during a putKind operation. Otherwise, the query fails with a "no index for this query" message.

RevSetClause Object

Defines a revision set—subset of an object's properties that your app can be notified about when one of the properties is modified. See Change Notification for more information.

// Schema

{
      "name"  : string,
      "props" : RevSetPropClause array
}

Name	Required	Type	Description
name	Required	String	Name of the revision set (unique to this kind).
props	Required	Object array	Array of properties to include in revision set.

operation Object

Object used to represent a batch operation to run.
(This object has different format as product. Following object example is for TV product).

{
      "method" : string,
      "params" : []
}

Name	Required	Type	Description
method	Required	String	Operation being requested.
params	Required	Any array	Params will depend on the type of operation being requested

ReserveIdsResponse Object

Contains operation success or failure flag and array of reserved db8 IDs returned from "reserveIds" call.

{
      "returnValue" : boolean,
      "ids"         : string array
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure
ids	Optional	String array	Array of reserved IDs.

SuccessResponse Object

Indicates operation success or failure.

// Schema
{
      "returnValue"  : boolean
}

// Example
{
      "returnValue": false
}

Name	Required	Type	Description
returnValue	Required	Boolean	Flag that indicates success/failure of the request. true: Success false: Failure

WhereClause Object

Defines a SQL-like JSON where clause for a DB8 Query.

// Schema
{
     "prop"    : string,
      "op"      : string,
      "val"     : any,
      "collate" : string
}
// Example
{
      "prop"    : "state",
      "op"      : "=",
      "val"     : "CA"
}

Name	Required	Type	Description
prop	Required	String	Name of property to test.
op	Required	String	Test operator. Must be one of the following: <, <=, =, >=, >, !=, %, ?, %% (less than, less than or equal, equals, greater than or equal, greater than, not equal, wildcard, and full-text) The % operator (aka - the prefix operator) will return all matches beginning with the value specified. The %% operator is used to locate substrings or partial string matches.
val	Required	Any	Value to test against.
collate	Optional	String	Indicates the string comparison routine used to order the results. See the collate field in the IndexPropClause data structure for more information.

FilterClause Object

Definition of the Filter clause that is part of the Query object.

// Schema
{
      "prop"    : string,
      "op"      : string,
      "val"     : any,
      "collate" : string
}

// Example
{
      "prop" : "state",
      "op"   : "=",
      "val"  : "CA"
}

Name	Required	Type	Description
prop	Required	String	Name of property to test.
op	Required	String	Test operator. Must be one of the following: <, <=, =, >=, >, !=, ?, %, %% (less than, less than or equal, equals, greater than or equal, greater than, not equal, wildcard, full-text, and partial-text) The % operator (aka - the prefix operator) will return all matches beginning with the value specified. The %% operator is used to locate substrings or partial string matches.
val	Required	Any	Value to test against.
collate	Optional	String	Indicates the string comparison routine used to order the results. See the collate field in the IndexPropClause data structure for more information.

PutResult Object

Contains "id" and "rev" fields in PutResponse for JSON data object.

// Schema
{
      "id"    : any,
      "rev"   : any
} 

Name	Required	Type	Description
id	Required	Any	ID of the object that was put.
rev	Required	Any	Object's revision ID. Every DB8 object has this ID field. DB8 maintains a global rev id counter that is incremented every time a DB8 object is created or updated.

IndexPropClause Object

Defines index property for IndexClause.

// Schema
{
      "name"     : string,
      "collate"  : string,
      "default"  : any,
      "tokenize" : string,
      "type"     : string
}

Name	Required	Type	Description
name	Required	String	Name of property being indexed.
collate	Required	String	Indicates the string comparison routine used to order the index. Must be one of the following: default: Does binary comparison. primary: Compares base characters (for example, "a" < "b") without considering accents, case, or tone marks. secondary: Accents in the characters are considered secondary differences (for example, "as" < "às" < "at"). Other differences between letters can also be considered secondary differences, depending on the language. A secondary difference is ignored when there is a primary difference anywhere in the strings. tertiary: Upper and lower case differences in characters are distinguished at the tertiary level (for example, "ao" < "Ao" < "aò"). In addition, a variant of a letter differs from the base form on the tertiary level (such as "A" and "?"). A tertiary difference is ignored when there is a primary or secondary difference anywhere in the strings.
default	Optional	Any	Default value to set for this property at insertion time, if not present.
tokenize	Optional	String	Indicates if words in strings should be broken up, i.e., should "Hello World" become "Hello" and "World" for purposes of indexing. Must be one of the following: none: Does not tokenize. default: Use the default for the locale (which may strip stop-words). Stop-words are common words that are stripped for purposes of indexing, i.e., "the", "a", "an", "is", etc. all: Tokenizes all words.
type	Required	String	single or multi. Single property or multiple properties.

RevSetPropClause Object

Object for RevSetPropClause.

{
      "name"     : string
}

Name	Required	Type	Description
name	Required	String	Name of property to include in revision set.