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"
]
}
}
}
}
}