DoneJS StealJS jQuery++ FuncUnit DocumentJS
6.0.1
5.33.2 4.3.0 3.14.1 2.3.35
  • About
  • Guides
  • API Docs
  • Community
  • Contributing
  • Bitovi
    • Bitovi.com
    • Blog
    • Design
    • Development
    • Training
    • Open Source
    • About
    • Contact Us
  • About
  • Guides
  • API Docs
    • Observables
      • can-bind
      • can-compute
      • can-debug
      • can-deep-observable
      • can-define
      • can-define/list/list
      • can-define/map/map
      • can-define-backup
      • can-define-stream
      • can-define-stream-kefir
      • can-event-queue
      • can-kefir
      • can-list
      • can-map
      • can-map-compat
      • can-map-define
      • can-observable-array
      • can-observable-object
      • can-observation
      • can-observation-recorder
      • can-observe
      • can-simple-map
      • can-simple-observable
      • can-stream
      • can-stream-kefir
      • can-value
    • Views
      • can-attribute-observable
      • can-component
      • can-observable-bindings
      • can-stache
        • Tags
          • {{expression}}
          • {{{expression}}}
          • {{#expression}}
          • {{/expression}}
          • {{else}}
          • {{<partialName}}
          • {{!expression}}
          • {{-expression-}}
        • Helpers
          • and
          • console
          • debugger
          • domData
          • eq
          • for(of)
          • portal
          • if
          • joinBase
          • let
          • not
          • or
          • switch
          • case
          • default
        • Expressions
          • Bracket Expression
          • Call Expression
          • Hash Expression
          • KeyLookup Expression
          • Literal Expression
        • Methods
          • addBindings
          • addConverter
          • addHelper
          • addLiveHelper
          • from
          • safeString
        • Key Operators
          • ~compute
          • ./current
          • ../parent
          • scope
          • scope/key
          • this
          • key
        • Pages
          • Expressions
          • Helpers
        • Types
          • getterSetter
          • helper
          • helperOptions
          • sectionRenderer
          • simpleHelper
          • view
        • Deprecated
          • Helper Expression
          • scope.vars
          • {{data name}}
          • {{#each(expression)}}
          • {{#is(expressions)}}
          • {{#unless(expression)}}
          • {{#with(expression)}}
          • registerConverter
          • registerHelper
          • registerPartial
          • Legacy Scope Behavior
          • {{^expression}}
          • {{>key}}
      • can-stache-bindings
      • can-stache-converters
      • can-stache-element
      • can-stache-route-helpers
      • can-view-autorender
      • can-view-callbacks
      • can-view-import
      • can-view-model
      • can-view-parser
      • can-view-scope
      • can-view-target
      • steal-stache
    • Data Modeling
      • can-connect
      • can-connect-feathers
      • can-connect-ndjson
      • can-connect-tag
      • can-define-realtime-rest-model
      • can-define-rest-model
      • can-fixture
      • can-fixture-socket
      • can-local-store
      • can-memory-store
      • can-ndjson-stream
      • can-query-logic
      • can-realtime-rest-model
      • can-rest-model
      • can-set-legacy
      • can-super-model
    • Routing
      • can-deparam
      • can-param
      • can-route
      • can-route-hash
      • can-route-mock
      • can-route-pushstate
    • JS Utilities
      • can-assign
      • can-define-lazy-value
      • can-diff
      • can-globals
      • can-join-uris
      • can-key
      • can-key-tree
      • can-make-map
      • can-parse-uri
      • can-queues
      • can-string
      • can-string-to-any
      • can-zone-storage
    • DOM Utilities
      • can-ajax
      • can-attribute-encoder
      • can-child-nodes
      • can-control
      • can-dom-data
      • can-dom-events
      • can-dom-mutate
      • can-event-dom-enter
      • can-event-dom-radiochange
      • can-fragment
    • Data Validation
      • can-define-validate-validatejs
      • can-type
      • can-validate
      • can-validate-interface
      • can-validate-legacy
      • can-validate-validatejs
    • Typed Data
      • can-cid
      • can-construct
      • can-construct-super
      • can-data-types
      • can-namespace
      • can-reflect
      • can-reflect-dependencies
      • can-reflect-promise
      • can-types
    • Polyfills
      • can-symbol
      • can-vdom
    • Core
    • Infrastructure
      • can-global
      • can-test-helpers
    • Ecosystem
    • Legacy
  • Community
  • Contributing
  • GitHub
  • Twitter
  • Chat
  • Forum
  • News
Bitovi

~compute

  • Edit on GitHub

Pass a compute instead of a value if an observable is found within Call Expression.

~key

This makes non-helper expression arguments behave similarly to helper expression arguments.

{{#each(~todos)}} ... {{/each}}

Use

The following illustrates what ~some.key would return given different data structures:

// A non-observable JS object:
const data1 = { some: { key: "value" } };

//-> "value"

// A non-observable JS object w/ a function at the end
const data2 = { some: { key: function() {
    return "value";
} } };

//-> "value"

// A non-observable JS object with intermediate functions:
const data3 = { some: function() {
    return { key: "value" };
} };

//-> "value"

// A observable can-map
const data4 = { some: new ObservableObject( { key: "value" } ) };

//-> canCompute("value")

// A method on an observable can-map that reads observables
class Some extends ObservableObject {
    static props = {
        value: String,
    };

    key() {
        return this.value;
    }
}
const data5 = { some: new Some( { value: "value" } ) };

//-> compute(function(){ return this.value; })

Notice that ~ should only be used once in a value lookup expression.

CanJS is part of DoneJS. Created and maintained by the core DoneJS team and Bitovi. Currently 6.0.1.

On this page

Get help

  • Chat with us
  • File an issue
  • Ask questions
  • Read latest news