EntreeJS Class: Provider

new Provider(opts, schema)

Constructor for the data provider base class. This class cannot be used directly.

Options

connStr {String} , connection string.

Parameters:

Name	Type	Argument	Description
`opts`	object		Additional options. The only required option is `connStr`.
`schema`	object	<optional>	Defines the database schema such as fields, indexes, types and structure.

Source:

provider.js, line 26

Methods

<protected> _do()

Source:

provider.js, line 299

<virtual> _get()

Source:

provider.js, line 386

<protected> _getId()

Source:

provider.js, line 272

<protected> _getIdKey()

Source:

provider.js, line 292

<virtual> _insert()

Source:

provider.js, line 363

<virtual> _select()

Source:

provider.js, line 393

<protected> _setId()

Source:

provider.js, line 283

<virtual> _update()

Source:

provider.js, line 375

<virtual> _upsert()

Source:

provider.js, line 368

delete(context, item|identity, callback) → {null}

Removes the specified item from the data collection. If an item with the specified identity is not found an error is returned.

Parameters:

Name	Type	Argument	Description
`context`	Object	<optional>	provides context for the current execution. Usually this is information about the user making the call. Although this parameter is optional, it might be required by some interceptors, such as authorization.
`item\|identity`	Object \| String \| Number		the item or the identity of an item to be deleted.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 123

Returns:

Type: null

dispose(callback) → {null}

Releases its database connection, clears current state and any cached data.

This is utility method intended mainly for data provider implementers.

Parameters:

Name	Type	Description
`callback`	function	Optional callback that will be called when the provider is disposed.

Source:

provider.js, line 334

Returns:

Type: null

get(context, item|identity, callback) → {null}

Retrieves the specified item from the data collection. If an item with the specified identity is not found an error is returned.

Parameters:

Name	Type	Argument	Description
`context`	Object	<optional>	provides context for the current execution. Usually this is information about the user making the call. Although this parameter is optional, it might be required by some interceptors, such as authorization.
`item\|identity`	Object \| String \| Number		the item or the identity of an item to be retrieved.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 142

Returns:

Type: null

handleError(err, callback) → {null}

Creates new error object with the specified error message or error code.

This is utility method intended mainly for data provider implementers.

Parameters:

Name	Type	Argument	Description
`err`	string \| Error		This argument should be either error message, EntreeJS error code or error object.
`callback`	function	<optional>	Error handler. If omitted the error will be thrown immediately.

Source:

provider.js, line 348

Returns:

Type: null

init(callback) → {null}

This is utility method intended mainly for data provider implementers.

Parameters:

Name	Type	Description
`callback`	function	Optional callback that will be called when the provider is initialized.

Source:

provider.js, line 321

Returns:

Type: null

insert(context, items, callback) → {null}

Inserts new item in the data collecton. If an item with the same identity is already present in the data collection, the operation is aborted and an error is returned.

Parameters:

Name	Type	Argument	Description
`context`	object	<optional>	Provides context for the current execution. Usually this is information about the user making the call. Although this parameter is optional, it might be required by some interceptors, such as authorization.
`items`	object \| Array.<object>		An item or an array of items to be inserted in the data store.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 67

Returns:

Type: null

select(context, query, options, callback) → {null|Cursor}

Selects items in the data collection and returns a Cursor to the selected items.

This method can return a Cursor either directly or with a callback. In most cases a cursor is created and returned synchronously, but some interceptors like module:cache require a callback. If you plan to use asynchronous interceptors you have to use the callback form.

Select uses MongoDB query syntax. All Entree data providers should support the full specification.

Options

skip {Number}, the number of items to skip.
limit {Number}, limit the number of returned items.
sort {Object}, set to sort the documents coming back from the query.

Parameters:

Name	Type	Argument	Description
`context`	object	<optional>	Provides context for the current execution.
`query`	object	<optional>	Specifies selection criteria. To return all items in a collection, omit this parameter or pass an empty object.
`options`	object	<optional>	Additional options for the cursor.
`callback`	function	<optional>	Optional callback function that will be called when the Cursor is constructed.

Source:

provider.js, line 222

Returns:

The method returns null if a callback is provided otherwise it returns a Cursor.

Type: null | Cursor

Example

 // Select at most 10 teenagers starting from the 21th that matches the criteria:
 entree.users.select({ age: { $gte: 13,  $lte: 19 }})
     .skip(20)
     .limit(10)
     .sort({ age: 1 })
     .each(function (err, user)) {
         if (err) {
             return console.log(err);
         }
         console.log(JSON.stringify(user));
     });

 // Do the same but with a callback - the recommended way if interceptors are used on the select method:
 entree.users.select({ age: { $gte: 13, $lte: 19 }}, function (err, cursor) {
     if (err) {
         return console.log(err);
     }
     cursor
         .skip(20)
         .limit(10)
         .sort({ age: 1 })
         .each(function (err, user) {
             if (err) {
                 return console.log(err);
             }
             console.log(JSON.stringify(user));
         });
 });

 // Again the same but limitations set as options:
 entree.users.select({ age: { $gte: 13,  $lte: 19 }}, { skip: 20, limit: 10, sort: { age: 1 }}, function (err, cursor) {
     if (err) {
         return console.log(err);
     }
     cursor.each(function (err, user) {
         if (err) {
             return console.log(err);
         }
         onsole.log(JSON.stringify(user));
     });
 });

 // Get the total number of all users in the collection:
 entree.users.select(function (err, currsor) {
     cursor.count(err, count) {
         if (err) {
             return console.log(err);
         }
         console.log(count);
     });
 });

selectOne(context, query, options, callback) → {null}

This method is the same as select, but instead of cursor it returns the first item that matches the select and sort criteria. If there is no match, null is returned.

Parameters:

Name	Type	Argument	Description
`context`	object	<optional>	Provides context for the current execution.
`query`	object	<optional>	Specifies selection criteria.
`options`	object	<optional>	Additional options for the cursor.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 239

Returns:

Type: null

update(context, item, callback) → {null}

Updates the specified item with the provided fields. If an item with the specified identity could not be found an error is returned.

Parameters:

Name	Type	Argument	Description
`context`	Object	<optional>	provides context for the current execution. Usually this is information about the user making the call. Although this parameter is optional, it might be required by some interceptors, such as authorization.
`item`	Object		the item to be updated.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 104

Returns:

Type: null

upsert(context, item, callback) → {null}

Inserts new item in the data collection if the item is not present, otherwise updates it.

Parameters:

Name	Type	Argument	Description
`context`	Object	<optional>	provides context for the current execution. Usually this is information about the user making the call. Although this parameter is optional, it might be required by some interceptors, such as authorization.
`item`	Object		the item to be added or updated.
`callback`	Provider~actionCallback		The callback that handles the result of this action.

Source:

provider.js, line 85

Returns:

Type: null

use(fn) → {null}

Adds an interception module to this provider instance. See Interceptors tutorial for more details.

Parameters:

Name	Type	Description
`fn`	function	The function that handles the interception.

Source:

provider.js, line 265

Returns:

Type: null

Type Definitions

actionCallback(err, res)

This callback will be called after executing the method. The first parameter will contain an error object if an error occurred during execution, while the second parameter will contain the result from the execution if it was successful.

For insert, upsert and update operations the result should be an object containing the same set of fields that were originally passed plus any fields that were automatically updated, such as timestamps or identity fields.

NOTE: the returned result on insert, update and delete may differ slightly for the different providers, but if no error is returned the operation is considered successful.

Parameters:

Name	Type	Description
`err`	object	the error object upon unsuccessful execution.
`res`	object	the result object upon successful execution.

Source:

provider.js, line 38