autoform-arrays.js

// Track arrays; this allows us to add/remove fields or groups of fields for an array
// but still easily respect minCount and maxCount, and properly add/remove the same
// items from the database once the form is submitted.

ArrayTracker = function afArrayTracker() {
  var self = this;
  self.info = {};
};

ArrayTracker.prototype.getMinMax = function atGetMinMax(
  ss,
  field,
  overrideMinCount,
  overrideMaxCount
) {
  var defs = AutoForm.Utility.getFieldDefinition(ss, field);

  // minCount is set by the schema, but can be set higher on the field attribute
  overrideMinCount = overrideMinCount || 0;
  var minCount = defs.minCount || 0;
  minCount = Math.max(overrideMinCount, minCount);

  // maxCount is set by the schema, but can be set lower on the field attribute
  overrideMaxCount = overrideMaxCount || Infinity;
  var maxCount = defs.maxCount || Infinity;
  maxCount = Math.min(overrideMaxCount, maxCount);

  return { minCount: minCount, maxCount: maxCount };
};

ArrayTracker.prototype.initForm = function atInitForm(formId) {
  var self = this;

  if (self.info[formId]) return;

  self.info[formId] = {};
};

ArrayTracker.prototype.getForm = function atInitForm(formId) {
  var self = this;
  self.initForm(formId);
  return self.info[formId];
};

ArrayTracker.prototype.ensureField = function atEnsureField(formId, field) {
  var self = this;
  self.initForm(formId);

  if (!self.info[formId][field]) self.resetField(formId, field);
};

ArrayTracker.prototype.initField = function atInitField(
  formId,
  field,
  ss,
  docCount,
  overrideMinCount,
  overrideMaxCount
) {
  var self = this;
  self.ensureField(formId, field);

  if (self.info[formId][field].array != null) return;

  // If we have a doc: The count should be the maximum of docCount or schema minCount or field minCount or 1.
  // If we don't have a doc: The count should be the maximum of schema minCount or field minCount or 1.
  var range = self.getMinMax(ss, field, overrideMinCount, overrideMaxCount);
  var arrayCount = Math.max(range.minCount, docCount == null ? 1 : docCount);

  // If this is an array of objects, collect names of object props
  var childKeys = [];
  if (AutoForm.Utility.getFieldDefinition(ss, field + ".$").type === Object) {
    childKeys = ss.objectKeys(AutoForm.Utility.makeKeyGeneric(field) + ".$");
  }

  let collection = new Mongo.Collection(null);

  var loopArray = [];
  for (var i = 0; i < arrayCount; i++) {
    var loopCtx = createLoopCtx(
      formId,
      field,
      i,
      childKeys,
      overrideMinCount,
      overrideMaxCount
    );
    loopArray.push(loopCtx);
    collection.insert(loopCtx);
  }

  self.info[formId][field].collection = collection;
  self.info[formId][field].array = loopArray;
  var count = loopArray.length;
  self.info[formId][field].count = count;
  self.info[formId][field].visibleCount = count;
  self.info[formId][field].deps.changed();
};

ArrayTracker.prototype.resetField = function atResetField(formId, field) {
  var self = this;
  self.initForm(formId);

  if (!self.info[formId][field]) {
    self.info[formId][field] = {
      deps: new Tracker.Dependency()
    };
  }

  if (self.info[formId][field].collection) {
    self.info[formId][field].collection.remove({});
  }

  self.info[formId][field].array = null;
  self.info[formId][field].count = 0;
  self.info[formId][field].visibleCount = 0;
  self.info[formId][field].deps.changed();
};

ArrayTracker.prototype.resetForm = function atResetForm(formId) {
  var self = this;
  Object.keys(self.info[formId] || {}).forEach(function(field) {
    self.resetField(formId, field);
  });
};

ArrayTracker.prototype.untrackForm = function atUntrackForm(formId) {
  var self = this;
  if (self.info[formId]) {
    Object.keys(self.info[formId]).forEach(field => {
      if (self.info[formId][field].collection) {
        self.info[formId][field].collection.remove({});
      }
    });
  }
  self.info[formId] = {};
};

ArrayTracker.prototype.tracksField = function atTracksField(formId, field) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  return !!self.info[formId][field].array;
};

ArrayTracker.prototype.getField = function atGetField(formId, field) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  return self.info[formId][field].collection.find({});
};

ArrayTracker.prototype.getCount = function atGetCount(formId, field) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  return self.info[formId][field].count;
};

ArrayTracker.prototype.getVisibleCount = function atGetVisibleCount(
  formId,
  field
) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  return self.info[formId][field].visibleCount;
};

ArrayTracker.prototype.isFirstFieldlVisible = function atIsFirstFieldlVisible(
  formId,
  field,
  currentIndex
) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  var firstVisibleField = self.info[formId][field].array.find(function(
    currentField
  ) {
    return !currentField.removed;
  });
  return firstVisibleField && firstVisibleField.index === currentIndex;
};

ArrayTracker.prototype.isLastFieldlVisible = function atIsLastFieldlVisible(
  formId,
  field,
  currentIndex
) {
  var self = this;
  self.ensureField(formId, field);
  self.info[formId][field].deps.depend();
  var lastVisibleField = self.info[formId][field].array
    .filter(function(currentField) {
      return !currentField.removed;
    })
    .pop();
  return lastVisibleField && lastVisibleField.index === currentIndex;
};

ArrayTracker.prototype.addOneToField = function atAddOneToField(
  formId,
  field,
  ss,
  overrideMinCount,
  overrideMaxCount
) {
  var self = this;
  self.ensureField(formId, field);

  if (!self.info[formId][field].array) return;

  var currentCount = self.info[formId][field].visibleCount;
  var maxCount = self.getMinMax(ss, field, overrideMinCount, overrideMaxCount)
    .maxCount;

  if (currentCount < maxCount) {
    var i = self.info[formId][field].array.length;

    // If this is an array of objects, collect names of object props
    var childKeys = [];
    if (AutoForm.Utility.getFieldDefinition(ss, field + ".$").type === Object) {
      childKeys = ss.objectKeys(AutoForm.Utility.makeKeyGeneric(field) + ".$");
    }

    var loopCtx = createLoopCtx(
      formId,
      field,
      i,
      childKeys,
      overrideMinCount,
      overrideMaxCount
    );

    self.info[formId][field].collection.insert(loopCtx);
    self.info[formId][field].array.push(loopCtx);
    self.info[formId][field].count++;
    self.info[formId][field].visibleCount++;
    self.info[formId][field].deps.changed();

    AutoForm.resetValueCache(formId, field);
  }
};

ArrayTracker.prototype.removeFromFieldAtIndex = function atRemoveFromFieldAtIndex(
  formId,
  field,
  index,
  ss,
  overrideMinCount,
  overrideMaxCount
) {
  var self = this;
  self.ensureField(formId, field);

  if (!self.info[formId][field].array) return;

  var currentCount = self.info[formId][field].visibleCount;
  var minCount = self.getMinMax(ss, field, overrideMinCount, overrideMaxCount)
    .minCount;

  if (currentCount > minCount) {
    self.info[formId][field].collection.update(
      { index: index },
      { $set: { removed: true } }
    );
    self.info[formId][field].array[index].removed = true;
    self.info[formId][field].count--;
    self.info[formId][field].visibleCount--;
    self.info[formId][field].deps.changed();

    AutoForm.resetValueCache(formId, field);
  }
};

/*
 * PRIVATE
 */
var createLoopCtx = function(
  formId,
  field,
  index,
  childKeys,
  overrideMinCount,
  overrideMaxCount
) {
  var loopCtx = {
    formId: formId,
    arrayFieldName: field,
    name: field + "." + index,
    index: index,
    minCount: overrideMinCount,
    maxCount: overrideMaxCount
  };

  // If this is an array of objects, add child key names under loopCtx.current[childName] = fullKeyName
  if (childKeys.length) {
    loopCtx.current = {};
    childKeys.forEach(function(k) {
      loopCtx.current[k] = field + "." + index + "." + k;
    });
  }

  return loopCtx;
};