Field Metadata

1. Introduction to Field Metadata

Field metadata is a collection of descriptive information about model fields. It defines various fields used in the business scenario for that model, as well as the field type, length, default value, required status, readonly status, and relationships of each field. Through this metadata, the system can control data response, processing, and interaction according to a unified pattern. It also allows for the abstraction of common requirements, ensuring data consistency, accuracy, and integrity.

2. Field Metadata Attributes

2.1 labelName Field Label

The label name of the field, i.e., the semantic name of the field, usually displayed as the field name in the list page header or form page. For example, Contact Number.

2.2 modelName Model Name

The name of the model to which the field belongs. The model name here refers to the technical name of the model, such as ProductCategory.

2.3 fieldName Field Name

The technical name of the field, corresponding to the property name definition of the entity class, such as unitPrice. Before querying, the field name is converted to underscore naming based on the storage type, such as unit_price.

2.4 fieldType Field Type

Predefined field types in the system include string text, various numeric types, date types, option set types, JSON types, and various relationship types. For details, refer to the FieldType section.

2.5 optionCode Option Set Code

Option sets are generally used in scenarios where options are relatively fixed, the number of options is limited, but expansion support is needed. In OpenMeta, all option information is stored in the SysOptionSet and SysOptionItem.

When the field type is Option or MultiOption, the optionCode option set code property needs to be configured.

2.6 defaultValue Default Field Value

Configuration of the field’s default value. When creating a new record, if the current field is not assigned a value, the default value will be used.

Logic for assigning default values in the Create scenario: (1) Check if the field has a value (not NULL). If there is a value, use the current value, and the default value will not be used. An empty string “ for text fields and 0 for numeric fields are considered values.

(2) If the current field has not been assigned a value, the default value will be used.

(3) If the field is not configured with a default value, the default value corresponding to the field type will be used. Refer to the FieldType section for specific default values for different field types.

2.7 length Field Length

The length of the field, corresponding to the character length for string types and the number of digits for integer types and high-precision numeric types.

2.8 scale Decimal Places

Decimal places for float and high-precision numeric types, with a default of 2 decimal places.

2.9 required Required Field

Control for the field’s required property. OpenMeta’s data processing layer immediately performs validation, independent of the database. When creating or updating data, the field’s required property is checked. Unlike the database’s not null property, a required=true field must be assigned a value during creation, and the value cannot be empty (including not allowing empty strings). Updating this field cannot set it to null.

2.10 readonly Read-Only Field

Whether client updates are allowed. For fields with readonly=true, client/API assignments and updates are not allowed; only server-side updates are supported, such as for calculated or auto-fill fields. Client-side creation and updating data check this property, and an error will occur when assigning a value to a read-only field.

Audit fields createdId, createdTime, updatedId, and updatedTime are automatically maintained by the underlying system, defaulting to readonly=true.

2.11 hidden Hidden Field

Whether to hide this field by default on the client, defaulting to false.

2.12 copyable Copyable Field

Whether the data of the current field is copied when duplicating data on the client, defaulting to true. All fields are copyable, except for the primary key id field.

2.13 searchable Searchable Field

Whether this field can be used as a query condition in a general search scenario. Defaults to true, meaning all fields are searchable.

2.14 dynamic Dynamic Field

Whether this field a dynamic field. The default is false. The value of the dynamic field is automatically calculated at runtime and is not stored in the database.

Scenarios where it can be true: dynamic computed fields, dynamic cascade fields. The value of the dynamic field generally represents the calculation result of the latest data. When using dynamic computed fields, the impact on client performance needs to be considered.

2.15 translatable Translatable Field

In multilingual data scenarios, indicates whether the value of this field can be translated. translatable=true indicates that this field is a multilingual field. Defaults to false.

2.16 encrypted Encrypted Field

Whether this field is an encrypted field, defaulting to AES256 encryption.

2.17 maskingType Masking Type

When this field contains sensitive data, the data masking type can be configured according to rules for phone numbers, names, ID numbers, bank card numbers, etc.

When the client retrieves data through the API, the program will automatically mask the data of this field. The masking method can be configured to replace all or part of the field’s data with the **** string.

Masked fields do not affect cascade fields or calculated fields that are processed on the server side. This means calculated fields can rely on masked fields, or calculated fields can also be masked fields simultaneously.

The client can obtain sensitive data of specified fields through the getUnmaskedField interface, during which the server will record access logs of sensitive data.

• All: Full masking, replacing all characters with ****.
• Name: Name masking, retaining the first and last characters, and retaining the last character if the name has only two characters.
• Email: Email masking, retaining the first 4 characters.
• PhoneNumber: Phone number masking, masking the last 4 characters.
• IdNumber: ID number masking, retaining the first and last 4 characters.
• CardNumber: Card number masking, retaining the last 4 characters.

2.18 computed Computed Field

Indicates whether this field is a computed field. Computed fields can be configured with computation expressions and depend on other fields of the current model in the computation expression.

Currently, due to performance considerations, cross-model field references are not supported in a single computation expression. If necessary, you can read field data across models in Flow orchestration and participate in computations.

For dynamic=false computed fields, when the dependent fields change, recalculation is triggered automatically.

For dynamic=true computed fields, the computation result is not stored in the database. When reading this computed field, the computation is executed automatically.

2.19 expression Computation Expression

In the expression expression, you can reference other fields of the current model for computation. In the expression, common utility functions such as arithmetic operations, string functions, and date functions can be used.

For numeric types, high-precision computations are used to avoid precision loss, with 16 decimal places retained during the computation process, using the banker's rounding method at the end. Since the decimal places parameter configuration for numeric fields is generally less than or equal to 16, the precision of this computation process does not affect the precision control of the field itself.

OpenMeta uses AviatorScript as the expression engine and sets it to safe sandbox mode.

2.20 cascadedField Cascaded Field

Refers to the values of fields in related models through OneToOne/ManyToOne field references. The configuration format is dot-separated cascaded fields, with the left side being the OneToOne/ManyToOne field name of the current model, and the right side being the field name of the related model, such as productId.productName.

For dynamic=false cascaded fields, recalculation is triggered automatically when the dependent OneToOne/ManyToOne field changes.

For dynamic=true cascaded fields, it means that the cascaded value is not stored in the database. When reading this cascaded field, the latest field values are automatically cascaded.

This cascade is a logical cascade, not a database cascade.

2.21 relatedModel Related Model

The associated model for relational fields, i.e., the model name for OneToOne, ManyToOne, OneToMany, and ManyToMany field types. For ManyToMany field types, this associated model is the model name of the intermediate table.

2.22 middleModel Middle Model

The ManyToMany field stores the middle model for the relationship data between the left and right models, which is also the intermediate table.

2.23 relatedField Related Field

• When the field type is OneToMany, the related model stores the field name of the current model id.
• When the field type is ManyToMany, the middle model stores the field name of the current model id.
• In the case of OneToOne and ManyToOne, this attribute defaults to the id of the related model.

2.24 inverseLinkField Inverse Link Field

When the field type is ManyToMany, the field name in the target table that is linked to the middle table.

2.25 filters Filtering Conditions for Relational Fields

Basic filtering conditions for OneToOne, ManyToOne relational fields, used to filter optional data based on business scenarios. When executing queries, clients can carry fixed filtering conditions along with user search conditions; the relationship is an AND relationship.

2.26 columnName Data Table Column Name

Read-only field, the data table column name corresponding to the field, automatically converted from the field name, such as unit_price.

When the field name changes, the data table column name is synchronized by default. The automatic modification of the data table can be turned off through the global DDL switch to meet the scenario of submitting DDL in other ways.

2.27 description Field Description

The business description of the field.

3 Field Types FieldType

• The default value of a field is automatically set to its zero value based on the field type.
• The foreign keys of OneToOne and ManyToOne are logical foreign keys, not physical database foreign keys.

3.1 String

A field of string type, using length to configure the length of the string.

3.2 Integer

An integer type field, using length to configure the number of integer digits.

3.3 Long

Long integer type.

3.4 Double

Ordinary decimal type, used in scenarios that accept precision loss in calculations.

3.5 BigDecimal

Precise decimal type, used in high-precision calculation scenarios such as money, currency, and exchange rates.

3.6 Boolean

Boolean type field.

3.7 Date

Date type, LocalDate object, displayed in the format yyyy-MM-dd, such as 2024-02-29.

3.8 DateTime

Date and time type accurate to seconds, LocalDateTime object, stored as a timestamp in the database, displayed in the format yyyy-MM-dd HH:mm:ss, such as 2024-02-29 19:15:20.

3.9 Option Single Select

Single select field, must configure the OptionCode property, i.e., the option set code.

When saving the value of a single select field, the actual transmission and storage are the codes of the option entries.

When fetching the value of a single select field through the API, it defaults to returning the format [itemCode, itemName], i.e., returning both the code and name of the entry.

For configuration and usage of option sets, refer to the Option Set section.

3.10 MultiOption Multi Select

The difference between multi-select fields and single select fields is that multi-select fields allow multiple selections from the same option set. When saving, a list of code strings for the selected options is passed, and in the database, the codes of multiple option entries are stored, separated by ,.

When reading the value of a multi-select field through the API, it defaults to returning the format [[itemCode, itemName], ...], i.e., the codes and names of multiple options.

3.11 MultiString String List

Used to store multiple string values through a single field. In the program, it processes a string list object, and in the database, it is stored with , as the separator.

3.12 JSON JSON Field

JSON format field, generally used for storing JSON data and object conversion. When indexing and querying conditions for JSON data are required, manual processing is needed.

3.13 Filter Filter Condition Field

Used only for storing and converting filter condition objects, stored in the database as a string.

3.14 OneToOne One-to-One

Relational field, requires configuration of relatedModel and relatedField properties. The selected data is unique.

3.15 ManyToOne Many-to-One

Relational field, requires configuration of relatedModel and relatedField properties.

3.16 OneToMany One-to-Many

Data for the OneToMany field is generally added, edited, and deleted on the client side for a single piece of data by calling the model interface of the Many side.

For scenarios where multiple OneToMany field values are edited in batches:

(1) If the field value is [], an empty list indicates the deletion of all historical records.

(2) When the field value is not empty, such as [{...}, {...}], a list structure of Many side data, it automatically recognizes added, edited, and deleted records on the Many side and processes them accordingly.

3.17 ManyToMany Many-to-Many

(1) Updating ManyToMany Fields

In Create/Update scenarios, the values of ManyToMany fields are passed with a list of associated model IDs. For example, in an Update request:

{
	"id": 12,
	"attendeeIds": [1, 2, 3]
}
 
(2) Cascading Search for ManyToMany Fields
 
Use case: Filter data in the current table through the filter conditions of the associated table field. Refer to the [Query Conditions](../../develop/query) section for details.