Filters
Contents
Introduction
Filters work differently from queries. When searching with a regular query, steps like sorting and scoring are done to produce the result.
These are relatively costly operations. A filter does none of these steps. A filter only removes nodes from the result - and is executed after the query statement, if it exists.
As such, filters are the most efficient way of limiting hits when you only need basic comparison statements.
| It is recommended to use query filtering instead of filters, however they can be used simultaneously. |
Syntax
Filters are defined using a DSL (Domain Specific Language) expressed in JSON.
Below is an example of a filter used in the content-API
var result = contentLib.query({
start: 0,
count: 2,
query: "data.city = 'Oslo' AND fulltext('data.description', 'garden', 'AND') ",
filters: {
boolean: {
must: {
exists: {
field: "modifiedTime"
}
},
mustNot: {
hasValue: {
field: "myField",
values: [
"cheese",
"fish",
"onion"
]
}
}
},
notExists: {
field: "unwantedField"
},
ids: {
values: ["id1", "id2"]
}
}
});If specifying several filters on root level, the filters are automatically joined with a boolean "must" clause, meaning all filters much match.
The following filters are supported:
exists
The exists filter filter outs any document not containing any values in the given property.
- field (string)
-
The property path
{
"start": 0,
"count": 2,
"filters": {
"exists": {
"field": "publish.from"
}
}
}notExists
The notExists filter removes nodes containing values in the given property.
- field (string)
-
The property path
{
"start": 0,
"count": 2,
"filters": {
"notExists": {
"field": "publish.from"
}
}
}hasValue
The hasValue filter matches if document contain any of the values given in the value list
field (string) The property path
values (object[]) Array of values to decide a match
{
"start": 0,
"count": 2,
"filters": {
"hasValue": {
"field": "product",
"values" : [
"plunge saw",
"combination square",
"router",
"mitre saw"
]
}
}
}ids
The ids filter is a shorthand filter to filter on ids
values (string[]) Arrays of ids to match
{
"start": 0,
"count": 2,
"filters": {
"ids": {
"values": [
"0123456789",
"1234567890"
]
}
}
}boolean
The boolean filter combines functions in logical expressions
- must (filter[])
-
All functions on the must array must evaluate to true for the filter to match
- mustNot (filter[])
-
All functions in the mustNot array must evaluate to false for the filter to match
- should (filter[])
-
One or more of the functions in the should array must evaluate to true for the filter to match
{
"start": 0,
"count": 2,
"filters": {
"boolean": {
"must": {
"exists": {
"field": "modifiedTime"
}
},
"mustNot": {
"hasValue": {
"field": "myField",
"values": [
"cheese",
"fish",
"onion"
]
}
}
}
}
}