Where to write reusable code to access in all the models

Questions and Answers Strapi Backend
1
System Information
  • Strapi Version: 3.2.5
  • Operating System: Ubuntu
  • Database: Postgresql
  • Node Version:14.15.3
  • NPM Version: 6.14.9
  • Yarn Version: 1.22.10

Hi i have a piece of code which i am using for external id encryption and decrytion.
The code is working fine.
but i am facing the code redundancy issue. as i have placed same code in all the models/{modelName}.js

Here is the small snippet i am trying to use…
./api/{apiName}/models/{modelName}.js

const Hashids = require("hashids/cjs");
const hashids = new Hashids("RandomSalt", 10);

/**
 * Read the documentation (https://strapi.io/documentation/v3.x/concepts/models.html#lifecycle-hooks)
 * to customize this model
 */
function decrypt(id) {
  id = hashids.decode(id);
  if (id.length === 0) return 0;
  else if (id.length === 1) return Number(id[0]);
  return id;
}
function decryptId(params) {
  if (params.id) params.id = decrypt(params.id);
  return params;
}
module.exports = {
  /**
   * Triggered before products find
   */

      lifecycles: {
        async beforeFind(params, populate) {
          params = decryptId(params);
        },
    }
}

const Hashids = require(“hashids/cjs”);
const hashids = new Hashids(“RandomSalt”, 10);
function decrypt(id){..}
function decryptId(params){...}

now where can i add this reusable functionality
so that somehow i can call them at all the models/{ModelName}.js.
Thank you.

1 Like
2

You should not write business logic inside the model/{model}.js files.

For these purposes you can use functions:
https://strapi.io/documentation/developer-docs/latest/concepts/configurations.html#functions

Create a file under ./config/functions/encryption.js

With the content:

const Hashids = require("hashids/cjs");
const hashids = new Hashids("RandomSalt", 10);

module.exports = {
  async decrypt(id) {
     id = hashids.decode(id);
     if (id.length === 0) return 0;
     else if (id.length === 1) return Number(id[0]);
     return id;
  },
  async decryptId(params) {
     if (params.id) params.id = decrypt(params.id);
     return params;
  }
}

Now these functions are accessible from anywhere as follows:

  • await strapi.config.functions['encryption'].decrypt(id)
  • await strapi.config.functions['encryption'].decryptId(params)
3 Likes
3

Thank you very much :slight_smile:

4

Hey Sunny, great answer. Just out of curiosity for learning purposes, why should we not write core business functions inside the model.js files?

5

They are used for life cycles, and this structure will change likely later on in 2021.

2 Likes
6

I tried the same for Strapi v4, but it does not work. Is this still supposed to work the same way?

const slug = await strapi.config.functions['utils'].slugify(data.name);


error: Cannot read properties of undefined (reading 'utils')

TypeError: Cannot read properties of undefined (reading 'utils')

    at Object.afterUpdate ((...)\src\api\cookbook\content-types\cookbook\lifecycles.js:13:51)

    at modelsLifecyclesSubscriber ((...)\node_modules\@strapi\database\lib\lifecycles\subscribers\models-lifecycles.js:15:41)

    at Object.run ((...)\node_modules\@strapi\database\lib\lifecycles\index.js:47:17)

    at Object.update ((...)\node_modules\@strapi\database\lib\entity-manager.js:260:27)

    at async Object.update ((...)\node_modules\@strapi\strapi\lib\services\entity-service\index.js:219:18)

    at async Object.<anonymous> ((...)\node_modules\@strapi\strapi\lib\services\entity-service\index.js:67:20)

    at async Object.update ((...)\node_modules\@strapi\plugin-content-manager\server\controllers\collection-types.js:123:27)

    at async returnBodyMiddleware ((...)\node_modules\@strapi\strapi\lib\services\server\compose-endpoint.js:52:18)

    at async module.exports ((...)\node_modules\@strapi\plugin-content-manager\server\middlewares\routing.js:39:3)

    at async policiesMiddleware ((...)\node_modules\@strapi\strapi\lib\services\server\policy.js:24:5)    at async (...)\node_modules\@strapi\strapi\lib\middlewares\body.js:24:7

    at async (...)\node_modules\@strapi\strapi\lib\middlewares\logger.js:22:5

    at async (...)\node_modules\@strapi\strapi\lib\middlewares\powered-by.js:16:5

    at async cors ((...)\node_modules\@koa\cors\index.js:95:16)

    at async (...)\node_modules\@strapi\strapi\lib\middlewares\errors.js:13:7

    at async (...)\node_modules\@strapi\strapi\lib\services\metrics\middleware.js:29:5
7

You can create a file called index.js inside the config folder. Inside it you can define functions like this

    module.exports = {
      async something(param) {
        
      },
    };

Then use it somewhere like this: strapi.config.index.something(param);

5 Likes
8

This works for me thanks very much!

9

Is there any way to access the strapi object in these functions, e.g. await strapi.service("api::list.list").find(...)

10

worked for v4.4, also your file name in config folder can be everything, it’s not have to called index.js