Filterparams Client

This is a library, which provides an object oriented approach to define queries and output them into a filterparams compatible format.

Installation

The package is available on npm. Simply install it through npm into your project.

npm install --save-dev filterparams

At the moment the project is not available on bower, due to the necessity in bower to keep compiled data in the repository. You're welcome to host it yourself. I refuse to keep any compiled data in the main git repository.

Usage

At the moment the package provided is using node modules. The package provides a public api when directly importing it.

var params = require('filterparams');
 
var query = params.query();
var filters = params.filters({
    equals: 'eq',
    greater: 'gt',
    lesser: 'lt',
    like: 'like'
});
 
query = (
    query.filter(
        params.or(filters('firstName').equals('joe'), 
                  filters('lastName').like('%doe%')))
    .filter(filters('age').greater(25))
    .order('lastName', true)
    .order('firstName')
);
 
console.log(query.generateParams());

This would generate:

{ 'filter[binding]': '(firstName|lastName)&age',
  'filter[param][firstName][eq]': 'joe',
  'filter[param][lastName][like]': '%doe%',
  'filter[param][age][gt]': 25,
  'filter[order]': [ 'desc(lastName)', 'asc(firstName)' ] }

You can then pass this data into the AJAX request of your choice to request the data from your backend.

API

The external API provides the following functions:

Filters

The #filters function is a convenience method to create parameters for specific filters, which are easier readable than specifying the parameters through the #params function.

You must know which filters are supported by the backend and their filter code. Then you can create a configuration object with the names of the created functions as keys and the filter code as values.

var filters = require('filterparams').filters({
    'equals': 'eq',
    'like': 'like'
});
 
console.log(filters('name').like('%brand%'));
# >>> Parameter { name: 'name', filter: 'like', alias: null, value: '%brand%' }
 
console.log(filters.equals('name', 'brand'));
# >>> Parameter { name: 'name', filter: 'eq', alias: null, value: 'brand' }

These are equivalent to:

console.log(require('filterparams').param('name', 'eq', 'brand'));

Query

The Query class is designed to not change their state. This means that every changing method in the query is creating and returning a new query object.

Thus existing queries can be kept for preconfiguration purposes.

The query class has the following functions:

• #filter(filterObj) - Applies a filter to the query. If there are already filters present in the configuration the passed filter is combined with the existing ones through an AND combination.
• #order(orderName, isDesc) - Applies an order configuration to the query. It can be called multiple times and is then concatenated. So query.order('firstName', true).order('lastName') would generate query which result is first ordered by firstName in descending order and afterwards by lastName in ascending order.
• #generateParams() - Generates the object which has to be passed to the AJAX request and serializes the configuration of the query into the filterparams format.

Combinations

Combinations of parameters can be arbitrarily nested. If you for example would like to express the following SQL Statement:

SELECT * FROM users WHERE (firstName = 'john' and lastName = 'doe' and age > 25) or lastName != 'ryan'

you can do so with the following javascript code:

var params = require('filterparams');

var query = params.query();
var filters = params.filters({
    equals: 'eq',
    greater: 'gt'
});

query = (
    query.filter(
        params.or(
            params.and(filters('firstName').equals('john'), 
                       filters('lastName').equals('doe'),
                       filters('age').greater(25)),
            params.not(filters('lastName').equals('ryan')))
);

console.log(query.generateParams());

License

The project is licensed under the MIT License.

Server Side Bindings

At the moment the following parsers exist for parsing the filterparams definition in a server side application.

• Go - go-filterparams
• Python - filterparams