This is an experimental library to test a new way of managing global state in Vue applications.

The Branch Plugin structures the global state as one or multiple roots (think of individual state modules), where each root should have the entire state needed by a feature or a view.

Then, by adding the Branch Mixin to a component, we can pick any branch of the state to be mapped to the component's data.

When the component's branch data is mutated, it will update the root state.

The branch is an object that gets mapped to this.branch in the component's data. It is constructed by picking the key-value pairs of the object found at the specified object path.

All branches have the following properties:

1. root - the name of the root to be used
2. path - the string containing a valid object path
3. keys - the array of keys to be picked and mapped to this.branch

main.js

import { BranchPlugin } from "vue-data-branch";

Vue.use(BranchPlugin, { roots: [
  {
    name: "someName",
    initialData: {
      some: {
        nested: {
          property: {
            a: 1,
            b: 2,
            c: 3,
            d: 4
          }
        }
      }
    }
  }
]});

SomeComponent.vue

import { BranchMixin } from "vue-data-branch";

export default {
  mixins: [BranchMixin],
  branch: {
    root: "someName",
    path: "some.nested.property",
    keys: ["a", "b"]
  },
  mounted() {
    console.log(this.branch); // will display { a: 1, b: 2 }
  },
  methods: {
    update() {
      this.branch.a += 1;  // branch properties can be mutated directly
    }
  }
}

If we want to dinamically construct the branch options, we can define the getRootName, getBranchKeys and getBranchPath methods on our component.

methods: {
  getRootName() {
    return "someName";
  },
  getBranchPath() {
    return "some.nested.property";
  },
  getBranchKeys() {
    return ["a", "b"];
  }
}

By default, when the branch is mutated, it will update the root's state automatically.
But, we can use the shouldUpdateBranch method in our component to control when to update the root state.

Example:

methods: {
  // the root state will be updated only if this.branch.a is even.
  shouldUpdateBranch() {
    if (this.branch.a % 2 === 0) {
      return true;
    }
    return false;
  }
}

By default, all branches are kept in sync with the root data.

But, if we use the same branch in multiple components and we want to control how or when the component's branch data will be synced, then we can define the handleConflictSync method.

Example:

methods: {
  handleConflictSync() {
    if (this.syncedBranch.a % 2 !== 0) {
      return; // do not sync if the "a" property is not even
    }
    this.syncBranch(); // sync the branch manually
  }
}

Feel free to dive in! Open an issue or submit PRs.