Plugins

Plugins modify the behaviour of Field, Model and Query classes simply by overloading their methods.

To load plugins into the ORM, use Knorm.prototype.use:

const { knorm } = require('@knorm/knorm');
const { knormRelations } = require('@knorm/relations');
const { Model, Query } = knorm({
/* knorm options */
}).use(
knormRelations({
/* plugin options */
})
);

see @knorm/relations for this plugin's documentation

Available plugins

PluginDescription
@knorm/postgresenables connecting to postgres
@knorm/to-jsonadds a toJSON method to Model
@knorm/relationsenables SQL joins
@knorm/soft-deleteenables soft-deletion
@knorm/paginateenables counting and paginating rows
@knorm/timestampsenables timestamps

Creating custom plugins

A Knorm plugin can be any named function or an object with an init function and a name property. See Knorm.prototype.use more info.

When a plugin is loaded via Knorm.prototype.use, the function (or object's init function) is called with the knorm instance. The plugin can then modify the classes on the instance:

const preventDelete = knorm => {
class YouShallNotDelete extends knorm.Query {
async delete() {
throw new Error('deleting is not allowed!');
}
}
knorm.updateQuery(YouShallNotDelete);
};
const { Model } = knorm().use(preventDelete);
Model.delete().catch(console.log);
// result:
// Error('deleting is not allowed!')
info

Knorm provides some utility methods for plugins to update the instance's classes:

  • Knorm.prototype.updateTransaction
  • Knorm.prototype.updateModel
  • Knorm.prototype.updateQuery
  • Knorm.prototype.updateField
  • Knorm.prototype.updateConnection
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