Logs

Logs represent events, both active and passive. Observations, harvests, and inputs are all types of Logs. Modules can provide additional Log types.

Type

Each Log must have a type. All Log types have a common set of attributes and relationships. Specific Log types may also add additional attributes and relationships (collectively referred to as "fields"). Log types are defined by modules, and are only available if their module is enabled. The modules included with farmOS define the following Log types:

• Activity
• Observation
• Input
• Harvest
• Lab test
• Maintenance
• Medical
• Seeding
• Transplanting

ID

Each Log will be assigned two unique IDs in the database: a universally unique identifier (UUID), and an internal numeric ID.

The UUID will be unique across farmOS databases. The internal ID will only be unique to a single farmOS database. Therefore, the farmOS API uses UUIDs to ensure that IDs pulled from multiple farmOS databases do not conflict. Internally, farmOS modules use the internal IDs to perform CRUD operations.

Attributes

Logs have a number of attributes that serve to describe their meta information. All Logs have the same standard set of attributes. Modules can add additional attributes.

Standard attributes

Attributes that are common to all Log types include:

• Name
• Timestamp
• Status
• Flags
• Geometry
• Is movement
• Notes
• Data

Name

Logs must have a name that describes them. This will be automatically generated using a type-specific naming pattern if the Log is saved with an empty name. The name is used in lists of Logs to easily identify them at quick glance.

Timestamp

Logs always have a timestamp which indicates when they took place.

Status

Logs can be marked as "pending" or "done", to indicate whether they are "planned" or "actual" events. Every change that is made to a Log is stored as a revision, so that it's possible to see how a plan evolves over time until it eventually becomes a canonical record of the event that took place.

Flags

Flags can be added to Logs to help with sorting and filtering. farmOS provides a set of default flags, including "Priority", "Needs review", and "Monitor". Modules can provide additional flags, such as "Organic".

Geometry

Geometry data can be added to a Log to describe where it took place using points, lines, and polygons.

When combined with the "Is movement" attribute (below), this will update the computed geometry of all Assets referenced on the Log.

See the "Geometry" attribute of Assets. For more information, see farmOS Location Logic.

Is movement

A Log can be designated as a "movement" to indicate that any Assets referenced by it are being moved to the specified locations and/or geometry (see "Geometry" above and "Locations" below).

If a Log is designated as a movement, and no location or geometry are defined, then the referenced Assets will no longer have a location or geometry.

For more information, see farmOS Location Logic.

Notes

Notes can be added to a Log to describe it in more detail. This is a freeform text field that allows a limited set of HTML tags, including links, lists, blockquotes, emphasis, etc.

Data

Logs have a hidden "data" field on them that is only accessible via the API. This provides a freeform plain text field that can be used to store additional data in any format (eg: JSON, YAML, XML). One use case for this field is to store remote system IDs that correspond to the Log. So if the Log is created or managed by software outside of farmOS, it can be identified easily. It can also be used to store additional structured metadata that does not fit into the standard Log attributes.

Additional attributes

Logs may contain additional attributes:

• Is group assignment

Is group assignment

A log can be designated as a "group assignment" to indicate that any Assets referenced by it are being assigned to the referenced Group Assets (see "Groups" below).

If a Log is designated as a group assignment, and no Group Assets are referenced, then the referenced Assets will no longer be members of a group.

For more information, see farmOS Group Membership Logic.

Relationships

Logs can be related to the Assets and location(s) they pertain to. They can have quantitative data via related Quantities. They can be assigned to the Users who are responsible for them. And they can be organized using Terms and other metadata.

These relationships are stored as reference fields on Logs. References are uni-directional, meaning that Logs reference Assets, but Assets do not reference Logs. It is possible to retrieve all Logs that reference a particular Asset, as well as retrieve all Assets referenced by a Log.

All Logs have the same standard set of relationships. Modules can add additional relationships.

Standard relationships

Relationships that are common to all Log types include:

• Assets
• Locations
• Quantities
• Owners
• Categories
• Images
• Files

Assets

Logs can specify which Assets they pertain to. Over time, this builds a rich historical record of everything that has happened to a particular Asset.

Locations

Logs can reference Assets that are designated as "locations" to indicate where they took place.

This differs from the Assets relationship described above. The distinction is:

• The "Asset" relationship means "this happened TO this Asset".
• The "Location" relationship means "this happened IN this Asset".

This distinction is important, and it makes intuitive sense for many use-cases. For example, if you are creating a Maintenance Log, you can say that it was maintenance applied to a tractor Asset (referenced in the "Asset" field), and it was performed in a barn Asset (referenced in the "Location" field).

However, some cases are less intuitive - specifically when you want to represent an action that is being performed directly to Assets that are designated as locations.

For example: if you are applying an input to a pasture (represented as an Asset of type "Land"), then the action is happening both TO the pasture and IN the pasture. In this case, the pasture Asset can be referenced in either or both the "Asset" and "Location" fields. This decision is left up to the convention of the end-user or module that implements it.

When combined with the "Is movement" attribute (above), this will move all Assets referenced on the Log to the locations specified. For more information, see farmOS Location Logic.

See also: the "Is location" attribute of Assets.

Quantities

Quantities are records that contain quantitative data. These are used to represent things like input amounts, harvest totals, time tracking, etc. For more information, see: Quantities.

Owners

Logs can be assigned to one or more Users in farmOS.

Categories

Logs can be assigned to one or more categories to help with sorting and filtering.

Categories differ from the "Log Type" in a few ways:

• A Log can be in multiple categories.
• Categories of a Log can change.
• The same set of Categories is available across all Log types.
• Categories are optional, type is required.

Categories are therefore a more flexible and dynamic method of organizing sets of Logs, regardless of type.

Categories differ from "Flags" in that categories only apply to Logs. Flags can be applied to Assets, Plans, and Logs. Flags are intended to bring attention to a Log, and are often highlighted in the UI. Flags may also be added and removed from a Log (eg: adding/removing the "Needs review" flag), whereas categories will tend to be fixed.

Flags are also more strictly defined and controlled than categories. Categories are Terms in the "Log categories" vocabulary, so they can be added, edited, deleted, and rearranged through the UI. Flags must be defined in code by a module.

Images

Images can be attached to Logs. This provides a place to store photos associated with the task.

Files

Files can be attached to Logs. This provides a place to put documents such as Shapefiles, PDFs, CSVs, or other files associated with the task.

Additional relationships

Logs may contain additional relationships:

• Equipment used
• Groups

Equipment used

Logs can specify which Equipment Assets were used to perform a task.

This differs from the Assets field (described above), which is for referencing the Assets that were the focus of the task. For example, if a Tractor is used to cultivate a field, the "Equipment used" field would reference the Tractor, and the "Assets" field would reference a Land Asset representing the field.

This field is added to all Log types by default only if the Equipment module is enabled.

Groups

Logs can reference Group Assets, along with the "Is group assignment" attribute (above) to indicate which group(s) the Assets will be members of.

This field is added to all Log types by default only if the Group module is enabled.

For more information, see farmOS Membership Logic.

Type-specific fields

In addition to the fields that are common to all Log types described above, some types add additional type-specific fields. These include:

Harvest Logs

Harvest Logs have the following additional attributes:

• Lot number (string)

Input Logs

Input Logs have the following additional attributes:

• Lot number (string)
• Method (string)
• Purchase date (timestamp)
• Source (string)

Lab Test Logs

Lab Test Logs have the following additional attributes:

• Test type (string)
• Soil texture (string)

Lab Test Logs have the following additional relationships:

• Laboratory (Term reference)

Medical Logs

Medical Logs have the following additional attributes:

• Veterinarian (string)

Seeding Logs

Seeding Logs have the following additional attributes:

• Lot number (string)
• Purchase date (timestamp)
• Source (string)