cube.js playground暴露的几个不错的功能

通过源码我们查看playground 提供的功能就会看到自己很不错的直接可以拿来使用的工具
主要代码在packages/cubejs-server-core/src/core/DevServer.ts

获取数据库schema 信息

代码如下，属于一个内部方法，可以基于driver获取数据库的schema

 

app.get('/playground/db-schema', catchErrors(async (req, res) => {

      this.cubejsServer.event('Dev Server DB Schema Load');

      const driver = await this.cubejsServer.getDriver({

        dataSource: req.body.dataSource || 'default',

        authInfo: null,

        securityContext: null,

        requestId: getRequestIdFromRequest(req),

      });

​

      const tablesSchema = await driver.tablesSchema();

      this.cubejsServer.event('Dev Server DB Schema Load Success');

      if (Object.keys(tablesSchema || {}).length === 0) {

        this.cubejsServer.event('Dev Server DB Schema Load Empty');

      }

      res.json({ tablesSchema });

    }));

当然我们也可以自己编写，代码不难

获取定义的schema

核心是利用了FileRepository的能力，我们可以自己扩展（基于s3的。。。。）

  app.get('/playground/files', catchErrors(async (req, res) => {

      this.cubejsServer.event('Dev Server Files Load');

      const files = await this.cubejsServer.repository.dataSchemaFiles();

      res.json({

        files: files.map(f => ({

          ...f,

          absPath: path.resolve(path.join(this.cubejsServer.repository.localPath(), f.fileName))

        }))

      });

    }));

schema 生成

此处利用了schema-compiler 包内部的工具，当然我们也可以利用此工具包，进行schema 的生成

 app.post('/playground/generate-schema', catchErrors(async (req, res) => {

      this.cubejsServer.event('Dev Server Generate Schema');

      if (!req.body) {

        throw new Error('Your express app config is missing body-parser middleware. Typical config can look like: `app.use(bodyParser.json({ limit: \'50mb\' }));`');

      }

​

      if (!req.body.tables) {

        throw new Error('You have to select at least one table');

      }

​

      const driver = await this.cubejsServer.getDriver({

        dataSource: req.body.dataSource || 'default',

        authInfo: null,

        securityContext: null,

        requestId: getRequestIdFromRequest(req),

      });

      const tablesSchema = req.body.tablesSchema || (await driver.tablesSchema());

​

      const ScaffoldingTemplate = require('@cubejs-backend/schema-compiler/scaffolding/ScaffoldingTemplate');

      const scaffoldingTemplate = new ScaffoldingTemplate(tablesSchema, driver);

      const files = scaffoldingTemplate.generateFilesByTableNames(req.body.tables);

​

      const schemaPath = options.schemaPath || 'schema';

​

      await Promise.all(files.map(file => fs.writeFile(path.join(schemaPath, file.fileName), file.content)));

      res.json({ files });

    }));

参考资料

https://github.com/cube-js/cube.js/blob/master/packages/cubejs-server-core/src/core/DevServer.ts
https://cube.dev/docs/@cubejs-backend-server
https://cube.dev/docs/@cubejs-backend-server-core
https://cube.dev/docs/config