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Modules

---

When GoAdmin engine is building, some modules are built. Such as: database module, user authentication module. And this chapter tells you how to reuse the modules.

Database Module

Database module can be used afrer the engine set the global config. For example:

import (
    ...
    "github.com/GoAdminGroup/go-admin/engine"
    ...
)

func main() {

    ...

    eng := engine.Default()

    cfg := config.Config{
        ...
        Databases: config.DatabaseList{
            "default": {
                Host:       "127.0.0.1",
                Port:       "3306",
                User:       "root",
                Pwd:        "root",
                Name:       "godmin",
                MaxIdleCon: 50,
                MaxOpenCon: 150,
                Driver:     config.DriverMysql,
            },
        },
        ...
    }

    _ = eng.AddConfig(cfg). // Here the database module built.
        AddPlugins(adminPlugin).
        Use(r)

    // get mysql connection
    conn := eng.MysqlConnection()

    // get mssql connection
    conn := eng.MssqlConnection()

    // get postgresql connection
    conn := eng.PostgresqlConnection()

    // get sqlite connection
    conn := eng.SqliteConnection()

    // Note: you get a pointer here which is point to the global database connection object.
    // If you want to reuse in you table models file, then you should call before the .Use(r) method.
    // Or it will panic. Like:
    //
    // _ = eng.AddConfig(cfg).
    //     ResolveMysqlConnection(tables.SetConn)
    //     AddPlugins(adminPlugin).
    //     Use(r)
    //
    // In your tables.go:
    //
    // var conn db.Connection
    //
    // func SetConn(c db.Connection) {
    //    conn = c   
    // }
    // 
    // And then you call the conn in your table model file.

    // get connection by setter function
    eng.ResolveMysqlConnection(SetConn)

    ...
}

var globalConn db.Connection

func SetConn(conn db.Connection) {
    globalConn = conn
}

When you receive connection object, you can call the built-in sql helper methods:

import (
    ...
    "github.com/GoAdminGroup/go-admin/modules/db"
    "github.com/GoAdminGroup/go-admin/modules/db/dialect"
    ...
)

func main() {

    // pass the global connection object, then call the helper methods

    // query
    db.WithDriver(globalConn).Table("users").Select("id", "name").First()

    // update
    db.WithDriver(globalConn).Table("users").Where("id", "=", 10).
        Update(dialect.H{
            "name": "jack",
        })

    // insert
    db.WithDriver(globalConn).Table("users").
        Insert(dialect.H{
            "name": "jack",
        })  

    // delete
    db.WithDriver(globalConn).Table("users").Where("id", "=", 10).Delete()

    // and so on...
}

You can use APIs of the Connection too.

// Connection is a connection handler of database.
type Connection interface {

    // Initialize
    InitDB(cfg map[string]config.Database) Connection

    // Get the driver name
    Name() string

    // Close the connection
    Close() []error

    // Get the default delimiter
    GetDelimiter() string

    // Get the sql.DB
    GetDB(key string) *sql.DB

    // Query with the default connection
    Query(query string, args ...interface{}) ([]map[string]interface{}, error)

    // Exec with the default connection
    Exec(query string, args ...interface{}) (sql.Result, error)

    // Query with the specify connection which is the key of Databases of config.Config.
    QueryWithConnection(conn, query string, args ...interface{}) ([]map[string]interface{}, error)

    // Exec  with the specify connection which is the key of Databases of config.Config.
    ExecWithConnection(conn, query string, args ...interface{}) (sql.Result, error)

    // Transaction operations:

    // begin the transaction
    BeginTx() *sql.Tx
    QueryWithTx(tx *sql.Tx, query string, args ...interface{}) ([]map[string]interface{}, error)
    ExecWithTx(tx *sql.Tx, query string, args ...interface{}) (sql.Result, error)
    BeginTxWithReadUncommitted() *sql.Tx
    BeginTxWithReadCommitted() *sql.Tx
    BeginTxWithRepeatableRead() *sql.Tx
    BeginTxWithLevel(level sql.IsolationLevel) *sql.Tx
    BeginTxWithReadUncommittedAndConnection(conn string) *sql.Tx
    BeginTxWithReadCommittedAndConnection(conn string) *sql.Tx
    BeginTxWithRepeatableReadAndConnection(conn string) *sql.Tx
    BeginTxAndConnection(conn string) *sql.Tx
    BeginTxWithLevelAndConnection(conn string, level sql.IsolationLevel) *sql.Tx    
}

Also you can use the orm, for example, `gorm

package main

import (
    ...
    "github.com/jinzhu/gorm"
    ...
)

func initORM() {
    // conn is the global connection object
    orm, _ := gorm.Open("mysql", conn.GetDB("default"))
    // See more about gorm: https://gorm.io
}

User Authentication Module

When we write the page content, need to get the corresponding login user, and to validate its information, need to use user authentication module.

import (
    ...
    adapter "github.com/GoAdminGroup/go-admin/adapter/gin"
    "github.com/GoAdminGroup/go-admin/engine"
    ...
)

func main() {

    ...

    eng := engine.Default()

    cfg := config.Config{        
        ...
    }

    if err := eng.AddConfig(cfg).
        AddPlugins(adminPlugin, examplePlugin).
        Use(r); err != nil {
        panic(err)
    }

    r.GET("/admin", adapter.Content(func(ctx *gin.Context) (types.Panel, error) {
        // get the auth user
        user, _ := engine.User(ctx)

        // Verify the permissions
        if !user.CheckPermission("dashboard") {
            return types.Panel{}, errors.New("no permission") 
        }

        // Verify the roles
        if !user.CheckRole("operator") {
            return types.Panel{}, errors.New("no permission") 
        }
    })
    ...
}

Retrieve the auth user model in the data model functions:

import (
    ...
    "github.com/GoAdminGroup/go-admin/modules/auth"
    "github.com/GoAdminGroup/go-admin/plugins/admin/models"
    ...
)

func GetUserTable(ctx *context.Context) table.Table {
    // retrieve the auth user.
    user = auth.Auth(ctx)
}