JavaScript code samples

This document shows code samples in order to help you play JavaScript templates.

Pre-requisites

Before reading this article, we recommend that you read the documentation about JavaScript templates.

Create indexes for MongoDB

This template will produce a JSON containing all indexes that should be created in MongoDB according to the field requirements. It creates an index for searchable or sortable fields or entity references. It also creates a unique index for unique fields and a text index for searchable string fields.

JavaScript

/** Generate indexes for a model */
function _model(out, model) {

    const modelName = model.names.snake;

    const strings = { fields: {} };
    const uniques = {
        fields: {},
        options: { unique: true }
    };


    // Even if no fields have indexes, Include this collection
    // Get fields objects
    out[modelName] = model.fields.list.reduce((p, field) => {

        // Non primary fields
        if (field.primary) {
            return p;
        }

        // Only if the field is searchable, sortable a reference or is unique
        if (!(field.sortable || field.searchable || field.type === 'entity' || field.unique)) {
            return p;
        }

        const fieldName = field.names.snake;

        // Special text index for strings
        if (field.type === 'string' && field.searchable) {
            strings.fields[fieldName] = 'text';
        }

        // Normal indexes
        p[`${modelName}_${fieldName}`] = { fields: { [fieldName]: 1 } };

        if (field.unique) {
            p[`${modelName}_${fieldName}`].options = { unique: true };
            uniques.fields[fieldName] = 1;
        }

        return p;
    }, {});

    // Add labels
    if (Object.keys(strings.fields).length > 0) {
        out[modelName][`${modelName}__text`] = strings;
    }

    // Optimize unique indexes
    if (Object.keys(uniques.fields).length > 1) {
        // Remove unique from other indexes
        model.fields.unique.map(field => {
            const fieldName = field.names.snake;
            if (out[modelName][`${modelName}_${fieldName}`]) {
                delete out[modelName][`${modelName}_${fieldName}`].options;
            }
        });
        // Add unique
        out[modelName][`${modelName}__uniques`] = uniques;
    }

    return out;
}

const _output = models.reduce(_model, {});
return JSON.stringify(_output, null, 2);

Sample output

{
  "service": {
    "service_created_at": {
      "fields": {
        "created_at": 1
      }
    },
    "service_name": {
      "fields": {
        "name": 1
      },
      "options": {
        "unique": true
      }
    },
    "service__text": {
      "fields": {
        "name": "text"
      }
    }
  },
  "user": {
    "user_created_at": {
      "fields": {
        "created_at": 1
      }
    },
    "user_name": {
      "fields": {
        "name": 1
      }
    },
    "user_email": {
      "fields": {
        "email": 1
      },
      "options": {
        "unique": true
      }
    },
    "user_role": {
      "fields": {
        "role": 1
      }
    },
    "user_banned": {
      "fields": {
        "banned": 1
      }
    },
    "user__text": {
      "fields": {
        "name": "text",
        "email": "text",
        "role": "text"
      }
    }
  }
}

Output model description as JSON

This template will output a JSON that lists fields and resolves dependencies between models.

JavaScript

const _output = models.map((m) => {
    return {
        collection: m.names.snake,
        dependencies: m.dependencies.list.map((d) => {
            return d.names.snake
        }),
        fields: m.fields.list.map((f) => {
            const out = {
              name: f.names.snake,
              notes: f.notes,
              type: f.type,
              subtype: f.subtype,
              properties: []
            };
            // Convert boolean properties to list
            for (const prop of Object.keys(f)) {
                if (typeof f[prop] === 'boolean' && f[prop]) {
                    out.properties.push(prop)
                }
            }
            // Append model reference if any
            if (f.model) {
                out.reference = f.model.names.snake;
            }
            return out;
        })
    };
});

return JSON.stringify(_output, null, 4);

Sample output

[
    {
        "collection": "bookmark",
        "dependencies": [
            "user",
            "place"
        ],
        "fields": [
            {
                "name": "_id",
                "notes": null,
                "type": "string",
                "subtype": null,
                "properties": [
                    "primary",
                    "internal"
                ]
            },
            {
                "name": "created_at",
                "notes": null,
                "type": "datetime",
                "subtype": null,
                "properties": [
                    "sortable",
                    "internal"
                ]
            },
            {
                "name": "owner",
                "notes": "Current user when creating the bookmark",
                "type": "entity",
                "subtype": null,
                "properties": [
                    "unique",
                    "searchable",
                    "internal",
                    "ownership"
                ],
                "reference": "user"
            },
            {
                "name": "place",
                "notes": null,
                "type": "entity",
                "subtype": null,
                "properties": [
                    "unique",
                    "searchable"
                ],
                "reference": "place"
            }
        ]
    }
]