mongo-queryfilter
=================

Generate an object suitable for use as a a mongo query from a querystring or request object.

The filter function takes either a raw object, a node http request object or a string containing the "query" portion of the request (e.g. "param=foo¶m2=bar"). Numeric values will be cast as appropriate.


Options

``javascript
var querystring = '_p_value=bob';
var options = {
"prefix": "_p_" // Optional prefix for the key names. If present only keys starting with the prefix will be passed through
};
var result = require('mongo-queryfilter').filter(querystring, options);
`

Examples




$3


`javascript
var querystring = 'value=bob';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: "bob"}
`

$3

`javascript
var querystring = 'value=__ne_bob';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$ne: "bob"}}
`

$3

`javascript
var querystring = 'value=__gt_5;
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$gt: 5}}
`

The same applies to "\__lt_" "\__gte_" "\__lte_" (<, >= AND <=)

$3

`javascript
var querystring = 'value=__in_alice||bob';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$in: ['alice', 'bob']}}

$3

`javascript
var querystring = 'value=__all_alice||bob';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$all: ['alice', 'bob']}}
`

$3

`javascript
var querystring = 'value=__or_alice||bob';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$or: ['alice', 'bob']}}
`

$3

`javascript
var querystring = 'value=__exists_true';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$exists: true}}
`

$3

`javascript
var querystring = 'array="__elemMatch_alice__eq_a,bob__gt_1';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{array: {$elemMatch: {alice: 'a', bob: {$gt: 1}]}}
`

$3

`javascript
var querystring = 'array="__elemMatch_id__in_a||b,bob__gt_1';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{array: {$elemMatch: {id: {$in: ['a', 'b']}, bob: {$gt: 1}]}}
`

$3

Filters for values between two numbers.

`javascript
var querystring = 'value="__range_10_20';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$gte: 10, $lt: 20}}
`

$3

Filters for values not between two numbers.

`javascript
var querystring = 'value="__nrange_10_20';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$not: {$gte: 10, $lt: 20}}}
`

$3


`javascript
// define a function that returns an operator $thing, that doubles the value
var thingfn = function(value, helpers, operatorName, fieldName){
return value * 2;
};

var result = require('mongo-queryfilter').filter('extra.color=red&price=__thing_2', {operators: {'thing': {'fn': thingfn, 'ns': '$thing', "rawvalue": false}}});
`
Output:
`javascript
{"extra.color": "red", price: {$thing: 4}]}}

// Note that $thing isn't valid in mongo, just an example - this will allow you to inject more complicated operators
`

$3

You can apply multiple conditions to the same key to create ranges:

`javascript
var querystring = 'value=__gt_1&value=__lt_10';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{$and: [{value: {$gt: 1}},{value: {$lt: 10}}]}
`




$3

You can filter based on both relative and absolute dates.
There are the following date comparisons: dtgt,dtlt,dtgte,dtlte, dteq.
You can pass an absolute value in ISO8601 format (e.g. 2014-01-01) or as a timestamp (1388534400000)

Alternatively, you can pass a relative value e.g. "now" "5minutes" "1hour" "-2days" "4weeks", "1year"

`javascript
var querystring = 'value=__dtlte_2weeks';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{$value: {$lte: Date 2 weeks from now}}
`

$3


`javascript
var querystring = 'value=__bool_true';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: true}
`

$3

Sometimes, it is desirable to not cast to a number (e.g. 0 prefixed numeric strings)
`javascript
var querystring = 'value=__streq_007';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: "007"}
`

The same can be done for $in and $nin:

`javascript
var querystring = 'value=__strin_007||008';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
{value: {$in: ['007', '008']}}
`




Sorting

The module can also handle the generation of the sorting parameter for you. Values of the "sort" parameter will be used from the querystring.
A prefix can be used to avoid clashes.

`javascript
var querystring = 'sort=dt__-1';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
[[dt, -1]]
`

$3

Duplicate the sort parameter, in the order you wish the sort to occur in:

`javascript
var querystring = 'sort=dt__-1&sort=name__1';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
[["dt", -1], ["name", 1]]
`


$3

"asc" and "desc" are also supported as values

`javascript
var querystring = 'sort=dt__desc&sort=name__asc';
var result = require('mongo-queryfilter').filter(querystring);
`
Output:
`javascript
[["dt", -1], ["name", 1]]
`


$3

A prefix can be specified

`javascript
var querystring = '__sort=dt__-1&__sort=name__1&sort=ignored__1';
var result = require('mongo-queryfilter').filter(querystring, {"prefix": "__"});
`
Output:
`javascript
[["dt", -1], ["name", 1]]
``