nedb/docs/model.md

model

Handle models (i.e. docs) Serialization/deserialization Copying Querying, update

• model
  • static
    • .checkObject(obj)
    • .serialize(obj) ⇒ string
    • .deserialize(rawData) ⇒ document
    • .compareThings(a, b, [_compareStrings]) ⇒ number
    • .modify(obj, updateQuery) ⇒ document
    • .getDotValue(obj, field) ⇒ *
    • .areThingsEqual(a, a) ⇒ boolean
    • .match(obj, query) ⇒ boolean
  • inner
    • ~modifierFunctions : enum
    • ~comparisonFunctions : enum
    • ~logicalOperators
    • ~modifierFunction : function
    • ~comparisonOperator ⇒ boolean
    • ~whereCallback ⇒ boolean

model.checkObject(obj)

Check a DB object and throw an error if it's not valid Works by applying the above checkKey function to all fields recursively

Kind: static method of model
Params

• obj document | Array.<document>

model.serialize(obj) ⇒ string

Serialize an object to be persisted to a one-line string For serialization/deserialization, we use the native JSON parser and not eval or Function That gives us less freedom but data entered in the database may come from users so eval and the like are not safe Accepted primitive types: Number, String, Boolean, Date, null Accepted secondary types: Objects, Arrays

Kind: static method of model
Params

• obj document

model.deserialize(rawData) ⇒ document

From a one-line representation of an object generate by the serialize function Return the object itself

Kind: static method of model
Params

• rawData string

model.compareThings(a, b, [_compareStrings]) ⇒ number

Compare { things U undefined } Things are defined as any native types (string, number, boolean, null, date) and objects We need to compare with undefined as it will be used in indexes In the case of objects and arrays, we deep-compare If two objects dont have the same type, the (arbitrary) type hierarchy is: undefined, null, number, strings, boolean, dates, arrays, objects Return -1 if a < b, 1 if a > b and 0 if a = b (note that equality here is NOT the same as defined in areThingsEqual!)

Kind: static method of model
Params

• a *
• b *
• [_compareStrings] compareStrings -

  String comparing function, returning -1, 0 or 1, overriding default string comparison (useful for languages with accented letters)

model.modify(obj, updateQuery) ⇒ document

Modify a DB object according to an update query

Kind: static method of model
Params

• obj document
• updateQuery query

model.getDotValue(obj, field) ⇒ *

Get a value from object with dot notation

Kind: static method of model
Params

• obj object
• field string

model.areThingsEqual(a, a) ⇒ boolean

Check whether 'things' are equal Things are defined as any native types (string, number, boolean, null, date) and objects In the case of object, we check deep equality Returns true if they are, false otherwise

Kind: static method of model
Params

• a *
• a *

model.match(obj, query) ⇒ boolean

Tell if a given document matches a query

Kind: static method of model
Params

• obj document -

  Document to check

• query query

model~modifierFunctions : enum

Kind: inner enum of model
Properties

Name	Type	Default	Description
$set	modifierFunction		Set a field to a new value
$unset	modifierFunction		Unset a field
$min	modifierFunction		Updates the value of the field, only if specified field is smaller than the current value of the field
$max	modifierFunction		Updates the value of the field, only if specified field is greater than the current value of the field
$inc	modifierFunction		Increment a numeric field's value
$pull	modifierFunction		Removes all instances of a value from an existing array
$pop	modifierFunction		Remove the first or last element of an array
$addToSet	modifierFunction		Add an element to an array field only if it is not already in it No modification if the element is already in the array Note that it doesn't check whether the original array contains duplicates
$push	modifierFunction		Push an element to the end of an array field Optional modifier $each instead of value to push several values Optional modifier $slice to slice the resulting array, see https://docs.mongodb.org/manual/reference/operator/update/slice/ Difference with MongoDB: if $slice is specified and not $each, we act as if value is an empty array

model~comparisonFunctions : enum

Kind: inner enum of model
Properties

Name	Type	Default	Description
$lt	comparisonOperator		Lower than
$lte	comparisonOperator		Lower than or equals
$gt	comparisonOperator		Greater than
$gte	comparisonOperator		Greater than or equals
$ne	comparisonOperator		Does not equal
$in	comparisonOperator		Is in Array
$nin	comparisonOperator		Is not in Array
$regex	comparisonOperator		Matches Regexp
$exists	comparisonOperator		Returns true if field exists
$size	comparisonOperator		Specific to Arrays, returns true if a length equals b
$elemMatch	comparisonOperator		Specific to Arrays, returns true if some elements of a match the query b

model~logicalOperators

Kind: inner enum of model
Properties

Name	Default	Description
$or		Match any of the subqueries
$and		Match all of the subqueries
$not		Inverted match of the query
$where		Use a function to match

model~modifierFunction : function

Kind: inner typedef of model
Params

• obj Object -

  The model to modify

• field String -

  Can contain dots, in that case that means we will set a subfield recursively

• value document

model~comparisonOperator ⇒ boolean

Kind: inner typedef of model
Params

• a * -

  Value in the object

• b * -

  Value in the query

model~whereCallback ⇒ boolean

Kind: inner typedef of model
Params

• obj document