Overview
Simple util to provide the ability to evaluate targets based on simple evaluation conditions expressed as arrays.
Example
The below example shows the simple filter expressions on a collection.
// Import evaluate from the library
import { evaluate } from 'json-filter-expressions';
// JSON definition of filter
const json = {
"filter": ["all", ["==", "type", "document"], ["in", "tags", "example", "other"]]
}
// Example objects
const objects = [
{ type: "document", src: "https://alpacamaps/document1.json", tags: ["example"] },
{ type: "document", src: "https://alpacamaps/document2.json", tags: ["something"] },
{ type: "document", src: "https://alpacamaps/document3.json", tags: ["other"] },
{ type: "image", src: "https://alpacamaps/image.png", tags: ["example"] }
]
// Match the objects
const matched = evaluate(json.filter, objects);
// Returns [
// { type: "document", src: "https://alpacamaps/document1.json", tags: ["example"] },
// { type: "document", src: "https://alpacamaps/document3.json", tags: ["other"] }
// ]Supported Evaluators
- Existence: exists / exist / !exists / !exist
- Comparison: == / != / > / >= / < / <=
- Membership: in / !in
- Combining: all / any / none
Notes
- Comparisons are done as using lodash "isEqual".
- Run npm t to run tests
- Inspired based on mapbox style filters