Service - Category Tree Standard

Overview

Handler service for the standard category tree type.

Repository

https://bitbucket.org/stb_working/category-tree-standard/src/master/

DynamoDB tables

Standard Config Table Per Service

Configuration tags

{
	configTag: "CategoryTreeServiceNameTag"
	configKey: "CategoryTreeServiceNameTag"
	configValue: xxx // this own services CategoryTreeServiceNameTag, eg "CategoryTreeStandard"
}

{
	configTag: "CatalogGraphServiceName"
	configKey: "CatalogGraphServiceName"
	configValue: xxx // eg: "CatalogGraph"
}

{
	configTag: "CategoryTreeService"
	configKey: xxx // categoryTreeServiceNameTag, eg: "CategoryTreeStandard", this is what is saved in each catalog record
	configValue: {
		serviceName: xxx // eg: "CategoryTreeStandard", this is the actual deployed service name}
	}
}

{
	configTag: "defaultValue"
	configKey: "locationTreeAreaNodeId"
	configValue: {eg: id for USA, or international?}
}

{
	configTag: "defaultValue"
	configKey: "browseQuantity"
	configValue: {eg: 1}
}

Graph database

Service - Catalog Graph

• Structure allows for one category to be found at the same level of the graph (same parent) multiple times, but eg with different filters
• Structure keeps a record of all changes, so can be rolled back eg if a user makes changes incorrectly

Nodes

catalogNode

Service - Catalog Standard#catalogNode

categoryNode

Represents one parent-child relationship in the graph, is never edited or removed from the graph. One category can have any number of categoryNodes

• NodeIdentifierLabels: categoryNode
• NodeIdentifierProperties: categoryNodeId - random uuid

Properties:

1. catalogId (maybe not needed but maybe more efficient if have)
2. categoryId (maybe not needed but maybe more efficient if have)
3. searchType: sellOffer|product|variantProduct, will often match catalog's default unless specifically set not to, is the current generated setting and can change regularly
4. filter: full filter for this node, will often match catalog's default unless specifically set not to, is the current generated setting and can change regularly
5. requiredData: full requiredData for this node, will often match catalog's default unless specifically set not to, is the current generated setting and can change regularly

categoryNodeSettings

Versioned data Holding the editable settings for a categoryNode.

see 2021-02-22 - Maintaining change history using graph database#Situation 2: Editable settings

Properties:

1. searchType: sellOffer|product|variantProduct
2. searchTypeMatchParent: boolean, if true will be updated to always match the parent node's searchType setting, if false must manually update
3. filter: full or additional filter set for this node, will be empty if matching parent categoryNode's filter
4. filterMatchParent: none|match|append, if none does not update when parent updates, if match will always match parent, if append will add this node's filter to the parent's
5. requiredData
6. requiredDataMatchParent: none|match|append, if none does not update when parent updates, if match will always match parent, if append will add this node's requiredData to the parent's

user

One userId, is never edited or removed from the graph.

• NodeIdentifierLabels: user
• NodeIdentifierProperties: userId

category

Service - Category Standard#category

Relationships

hasChildCategoryNode / hasDisabledChildCategoryNode

Creates a link between two categoryNode vertices or catalogNode > categoryNode vertices, relationship can be enabled or disabled, one of these relationships will always exist linking the same parent to the same child.

One categoryNode can have multiple child categoryNodes but only one parent categoryNode, traversing up the parents will reach the final catalog node.

changedBy

Creates a link between categoryNode > user nodes, is never edited or removed from the graph. Each time a categoryNode is disabled or enabled a new relationship is created linking the userId and saving the date, so have record of changes

Handled automatically in 2021-02-16 - Graph Handler - Functions#Relationship/ChangeRelationshipType

isCategory

Creates a link between categoryNode > category nodes, is never edited or removed from the graph.

calculating categoryNode's requiredData and searchType

• In most cases all categoryNodes will share the same settings as the catalog's requiredData and searchType, but we allow for per categoryNode settings.
• Each categoryNode maintains it's own final setting so can be efficiently pulled when browsing
• If a categoryNode sets {setting}MatchParent = match it inherits the parent categoryNode's setting, if traversing up the tree to the catalog node all parents inherit, then any changes to the catalog's setting will propagate down to all categoryNodes

Initial settings

• searchType can only be match or not match (no append)
• If {setting}MatchParent = none: the setting cannot be empty, and is saved in both the categoryNodeSettings and categoryNode nodes
• If {setting}MatchParent = match: no requiredData data is saved in categoryNodeSettings and the parent categoryNode's settings value is saved in this categoryNode node
• If {setting}MatchParent = append: the requiredData cannot be empty and is saved into the categoryNodeSettings node, then appended to the parent's setting and saved in the categoryNode node
• If the parent is a catalog node the same rules apply but the catalog's filter is used

calculating categoryNode's filter

The categoryNode's stored/active filter uses MatchParent the same as requiredData above, however child categories might include products that are not part of a parent category, when browsing the parent category we want to show all results from the parent's filter as well as all children's combined.

If child categoryNode's match parent then we not need to add them into the parents final filter. If not we can chaing them using or statements to create the parent's final filter.

Processing these large filters can be efficient due to cached results.

When a categoryNode's filter changes

If a categoryNode or catalog's filter changes, just like requiredData we need to traverse down the tree checking for any filterMatchParent = match|append and rebuild the child node's filter setting accordingly, whenever a categoryNode is found that has no child nodes with filterMatchParent = match|append we can stop traversing down, but need to re-trace back up the tree recalculating the final combined filter that adds in all children filters.

When creating a new categoryNode

A new categoryNode also needs to traverse up the tree recalculating the filter for all parents

Adding client submitted settings

• client (or requesting service) can overwrite or adjust these settings

searchType

• client submitted setting overwrites categoryNode's

filter

• would get added as an and grouped filter

requiredData

• client setting overwrites categoryNode's if set

Top level results

• Each catalog has a top level record saved into CategoryNode table, categoryId = 0, this will be a combination of catalog filter, and all child categoryIds

Ideas

• This service could hold a list of Products for each category and do things like record popularity etc.. partial lists would be OK, anything we want to add. For features like popularity might not want to remove products when they no longer match the catagory, might want to maintain their details in case get added again. This type of idea might be served through the graph database.

Working documents

Category Tree Standard