Query Parser

The Query Parser is a utility for creating complex Nymph entity queries from a simple text input. Essentially, it turns a string into a Nymph query.

npm install --save @nymphjs/query-parser

The query parser will turn a string into an Options and Selectors array for the Nymph Client. It has a syntax that allows for most features of a Nymph query to be expressed in a text input.

import queryParser from '@nymphjs/query-parser';

import BlogPost from './BlogPost';
import Category from './Category';

async function doQuery() {
  const [options, ...selectors] = queryParser({
    query:
      'limit:4 sort:mdate foobar (| [archived] mdate<"2 weeks ago") category<{Cat Tech}>',
    entityClass: BlogPost,
    defaultFields: ['title', 'body'],
    qrefMap: {
      Cat: {
        class: Category,
        defaultFields: ['name'],
      },
    },
  });
  /*
  Options will be
    {
      class: BlogPost,
      limit: 4,
      sort: 'mdate'
    }

  And selectors will be (equivalent to)
    [
      {
        type: "|",
        truthy: [
          "archived"
        ],
        lt: [
          ["mdate", null, "2 weeks ago"]
        ]
      },
      {
        type: "&",
        qref: [
          "category",
          [
            {
              class: Category
            },
            {
              type: "|",
              ilike: ["name", "%Tech%"]
            }
          ]
        ]
      },
      {
        type: "|",
        ilike: [
          ["title", "%foobar%"],
          ["body", "%foobar%"]
        ]
      }
    ]
  */
  const entities = await nymph.getEntities(options, ...selectors);
}

You can set limit, offset, sort, and reverse like this.

• limit:number
• offset:number
• sort:string or sort:-
• reverse:true, reverse:false, reverse:1, or reverse:0

These must appear in the top level of the query (outside of any parentheses).

Using a dash for sort means the results will not be sorted in any particular order. You can also use "cdate" for created date and "mdate" for modified date.

These are the available clauses, and their syntax.

Check for string or JSON representation equality.

• name=string or -name=string
• name="string value" or -name="string value"
  • (Use this if you have a space in your string, or if your string could be interpreted as valid JSON. Escape double quotes with a leading backslash.)
• name=JSON or -name=JSON
  • (Match a JSON encoded value (like true, 1, [1,2,3], or {"prop":"val"}).)

Check for entity GUID.

• {guid} or -{guid}

Check for a tag.

• <name> or -<name>

Check for truthiness.

• [name] or -[name]

Check for a reference to another entity.

• name<{guid}> or -name<{guid}>

Check for a reference to another entity using a query.

• name<{refclassname inner query}> or -name<{refclassname inner query}>
  • (Escape curly brackets with a leading backslash.)
  • (Requires a map of refclassname to their actual class and default fields.)

Check if the array at the named property contains a value.

• name<value> or -name<value>
  • (Escape angle brackets with a leading backslash. If your value could be interpreted as valid JSON, encode it as a JSON string and use the JSON syntax instead.)
• name<JSON> or -name<JSON>
  • (Search for a JSON encoded value (like true, 1, [1,2,3], or {"prop":"val"}).)

Check for full-text search query match. Use single quotes to find sequential terms and double quotes to find exact terms. Use "or" as the or operator. Use "-" before a term as the negation operator. Stop words and punctuation are stripped. Case insensitive.

• name(query) or -name(query)
• name:query or name:'sequence query' or name:"exact query" or -name:query or -name:'sequence query' or -name:"exact query"
  • (The "limit", "offset", "sort", and "reverse" properties cannot be used with the colon syntax.)

Check for POSIX regex match.

• name~/pattern/ or -name~/pattern/

Check for case insensitive POSIX regex match.

• name~/pattern/i or -name~/pattern/i

Check for pattern match where _ is single char wildcard and % is any length wildcard.

• name~pattern or -name~pattern
• name~"pattern" or -name~"pattern"
  • (Use this if you have a space in your pattern.)

Check for case insensitive pattern match where _ is single char wildcard and % is any length wildcard.

• name~"pattern"i or -name~"pattern"i

Check a prop's value is greater than a given value.

• name>number or -name>number
• name>relative or -name>relative
  • (A single relative time value like now or yesterday.)
• name>"relative time value" or -name>"relative time value"
  • (Use this for a time value with a space like "two days from now", "last thursday", "+4 weeks", or "5 minutes ago".)

Check a prop's value is greater than or equal to a given value.

• name>=number or -name>=number
• name>=relative or -name>=relative
  • (A single relative time value like now or yesterday.)
• name>="relative time value" or -name>="relative time value"
  • (Use this for a time value with a space like "two days from now", "last thursday", "+4 weeks", or "5 minutes ago".)

Check a prop's value is less than a given value.

• name<number or -name<number
• name<relative or -name<relative
  • (A single relative time value like now or yesterday.)
• name<"relative time value" or -name<"relative time value"
  • (Use this for a time value with a space like "two days from now", "last thursday", "+4 weeks", or "5 minutes ago".)

Check a prop's value is less than or equal to a given value.

• name<=number or -name<=number
• name<=relative or -name<=relative
  • (A single relative time value like now or yesterday.)
• name<="relative time value" or -name<="relative time value"
  • (Use this for a time value with a space like "two days from now", "last thursday", "+4 weeks", or "5 minutes ago".)

You can specify nested selectors with different types using pairs of parentheses. The first character (or two) inside the parentheses can be a type: "&", "!&", "|", "!|", or "!" (the same as "!&").

Here are some examples of nested selectors.

Either enabled is truthy and abilities contains "subscriber", or abilities contains "lifelong-subscriber".

(| ([enabled] abilities<"subscriber">) abilities<"lifeline-subscriber">)


Published is not truthy and cdate is not greater than 6 months ago.

(! [published] cdate>"6 months ago")

Anything contained in the query (including in selector parentheses) that doesn't match any of the options or clause syntaxes listed above (bare query parts) will be added (at the appropriate nesting level) to a selector with an "|" type in an ilike clause surrounded by "%" characters for each field passed in to the defaultFields argument.

You can also supply a function in the option bareHandler that will handle bare query parts instead of the "Default Fields" behavior described above. It will receive three arguments, the query parts, the entity class, and the default fields entry for that class. It should return a partial selector that will replace or extend the "|" selector.