Function handleDiff

src/client.ts:34–124

(state, diff)

};

function handleDiff(state, diff) {
  let diffEntities = 0;
  let entitiesWithUpdatedValues = {};

  let records = indexes.records;
  let dirty = indexes.dirty;

  for(let remove of diff.remove) {
    let [e, a, v] = remove;
    if(!records.index[e]) {
      console.error(`Attempting to remove an attribute of an entity that doesn't exist: ${e}`);
      continue;
    }

    let entity = records.index[e];
    let values = entity[a];
    if(!values) continue;
    dirty.insert(e, a);

    if(values.length <= 1 && values[0] === v) {
      delete entity[a];
    } else {
      let ix = values.indexOf(v);
      if(ix === -1) continue;
      values.splice(ix, 1);
    }

    // Update indexes
    if(a === "tag") indexes.byTag.remove(v, e);
    else if(a === "name") indexes.byName.remove(v, e);
    else if(a === "class") indexes.byClass.remove(v, e);
    else if(a === "style") indexes.byStyle.remove(v, e);
    // @NOTE: We intentionally leak children -> parent for now to easily restore
    // children that get recreated with the same id which don't have an associated diff in their parent.
    //else if(a === "children") indexes.byChild.remove(v, e);
    else if(a === "value") entitiesWithUpdatedValues[e] = true;

  }

  for(let insert of diff.insert) {
    let [e, a, v] = insert;
    let entity = records.index[e];
    if(!entity) {
      entity = {};
      records.insert(e, entity);
      diffEntities++; // Nuke this and use records.dirty
    }

    dirty.insert(e, a);

    if(!entity[a]) entity[a] = [];
    entity[a].push(v);

    // Update indexes
    if(a === "tag") indexes.byTag.insert(v, e);
    else if(a === "name") indexes.byName.insert(v, e);
    else if(a === "class") indexes.byClass.insert(v, e);
    else if(a === "style") indexes.byStyle.insert(v, e);