gradconnection / immstruct-construct

Initialize localized immstruct data within each component, rather than forcing the building of the immstruct at the top.

This module provides the ability to initialize localized immstruct data within each component, rather than forcing the building of the immstruct at the top.

Usage

    /* This module provides the ability to initialize localized immstruct data
    within each component, rather than forcing the building of the immstruct at the
    top. */

    var immstruct = require("immstruct")
    var createConstruct = require('./index').createConstruct;

    /* Imagine attaching this function to FriendListItem.construct,
       FriendListItem is a `component`. */
    var FriendListItemState = createConstruct(function(name) {
      return {
        firstName: name,
        country: new Promise(function(resolve, reject) {
          setTimeout(function() {
            // Does a 1 second lookup, simulating API access.
            resolve(this.state.routeParams.country)
          }.bind(this), 1000)
        }.bind(this)),
      }
    })

    /* Imagine attaching this function to FriendList.construct,
       FriendList is a `component`.*/
    var FriendListState = createConstruct(function(names) {
      return {
        friendListItemStates: Promise.all(names.map(
            function(name, i) {
              return FriendListItemState(this, ["friendListItemStates", i], name)
            }.bind(this)))
      };
    })

    /* Imagine attaching this function to App.construct,
       App is a `component`.*/
    var AppState = createConstruct(function() {
      return {
        friendListState: FriendListState(this, "friendListState", 
          ["John", "Shepard", "Liara"])
      }
    });

    var structure = immstruct({});

    structure.on('swap', function(a, b, path) {
      console.log("swap at path:", path);
    })

    AppState({
      structure: structure,
      path: [],
      state: {
        routeParams: { country: "Australia" }
      }
    }).then(function() {
      console.log("All promises complete. structure:")
      console.log(JSON.stringify(structure.cursor().deref(), null, " "));
    });

    /* output:

    swap at path: [ 'friendListState', 'friendListItemStates', 0 ]
    swap at path: [ 'friendListState', 'friendListItemStates', 1 ]
    swap at path: [ 'friendListState', 'friendListItemStates', 2 ]
    swap at path: [ 'friendListState', 'friendListItemStates', 0 ]
    swap at path: [ 'friendListState', 'friendListItemStates', 1 ]
    swap at path: [ 'friendListState', 'friendListItemStates', 2 ]
    swap at path: [ 'friendListState' ]
    All promises complete. structure:
    {
     "friendListState": {
      "friendListItemStates": [
       {
        "firstName": "John",
        "country": "Australia"
       },
       {
        "firstName": "Shepard",
        "country": "Australia"
       },
       {
        "firstName": "Liara",
        "country": "Australia"
       }
      ]
     }
    }
    */

To run example:

 npm install
 node usage.js