myData Filter

Small filter library for working with immutable AST(abstract syntax trees) and queries

Installation

npm install mydata-filter

Usage

Compile a JSON-AST code that can be used later by a transformer:

import { Parse } from "mydata-filter";

const code = `(user.username == "Ana") or (username == "Mari")`;

Parse(code).then(ast => {
    console.log(ast); // { type: "...", ... }
}).catch(error => {
    console.error(error);
});

Compile a mysql where clause from a string using a transformer:

import { Parse } from "mydata-filter";
import MySqlTransformer from "mydata-filter-mysql";

const code = `(user.username == "Ana") or (username == "Ana")`;

Parse(code, {
    transformer: new MySqlTransformer({
        clause: "WHERE"
    })
}).then(query => {
    console.log(query); // (`user`.`username` == 'Ana') OR (`username` == 'Ana')
}).catch(error => {
    console.error(error);
});

Supported Functions

Parse(code, {
  cache?: boolean,
  transformer?: ITransformer
}): Promise<any>;

ParseSync(code, {
  cache?: boolean,
  transformer?: ITransformer
}): any;

Available Common Transformers

• mydata-filter-mysql
• mydata-filter-postgresql

Functions Syntax

FunctionName(arg1)
FUNCTION_NAME(arg1, arg2, ...)

Supported Operators

Name	Operator	Alias
Equals	==
Not Equals	!=
Less than or equal	<=
Greater Than or Equal	>=
Less Than	<
Greater Than	>
Logical And	&&	AND
Logical Or	||	OR
Contains	*=
Contains Word	~=
Starts With	^=
Ends With	=$
Arithmetic Add	+
Arithmetic Subtraction	-
Arithmetic Multiplication	*
Arithmetic Division	/
Sorter ascending	ASC
Sorter descending	DESC

Supported Features Identifiers Name

Name	Description
OR	Logical Or
AND	Logical And
LT	Less Than
GT	Greater Than
LE	Less than or equal
GE	Greater Than or Equal
NEQ	Not Equals
EQ	Equals
CONTAINS	Contains Operator
CONTAINS_WORD	Contains Word Operator
STARTS_WITH	Starts With Operator
ENDS_WITH	Ends With Operator
ADDITION	Arithmetic Addiction
SUBTRACTION	Arithmetic Subtraction
MULTIPLICATION	Arithmetic Multiplication
DIVISION	Arithmetic Division
PARENTHESES	Parentheses
IDENTIFIER_PATH	Deep Identifier separated by dot
IDENTIFIER	Simple identifier
BOOLEAN	Boolean Type
NUMBER	Number Type
STRING	String Type
FUNCTION_CALL	Call Function
ASC	Sort ascending
DESC	Sort descending
SORTING_LIST	Multiple sorters separated by comma