feat: Cities uses GenericHandler

lib/Handlers/Generic.handler.js

@@ -0,0 +1,59 @@
+"use strict";
+const { ROOT_PATH, LIB_PATH, MODELS_PATH, HANDLERS_PATH } = process.env;
+
+async function getPage( page, elements, Model, filter=null, projection=null){
+    const skip = elements * page;
+	const total = await Model.count( filter );
+	const list = await Model.find( filter , projection, { skip : skip , limit : elements } );
+	return {
+        total : total,
+        limit : elements,
+        skip : skip,
+		data : list 
+	}
+}
+
+async function getPageQuery(page, elements, Model, filter=null, projection=null){
+    const skip = elements * page;
+	const total = await Model.count( filter );
+	return {
+		query : Model.find( filter , projection, { skip : skip , limit : elements } ),
+		total : total,
+		skip : skip
+	};
+}
+
+class GenericHandler{
+    constructor( Model, search_param, populate_list=null ) {
+        this.Model = Model;
+        this.search_param = search_param;
+        this.populate_list = populate_list || [];
+    }
+
+    async populateQuey( query ){
+        if( this.populate_list.length > 0 ){
+            query.populate( this.populate_list );
+        }
+        return await query.exec();
+    }
+
+    async getList( page, elements, filter=null, projection=null ){
+        const { query } = await getPageQuery( page , elements, this.Model, filter, projection );
+        return await this.populateQuey( query );
+    }
+    
+    async findList( find_string, page, elements, projection=null ){
+        const search_param = this.search_param;
+        const re = new RegExp( find_string );
+        const filter = {};
+        filter[ search_param ] =  { $regex: re, $options: 'i' };
+        return await this.getList( page, elements, filter, projection );
+    }
+    
+    async getById( id, projection=null ){
+        const query = Model.findById( id, projection );
+        return await this.populateQuey( query );
+    }
+};
+
+module.exports = { getPage, getPageQuery, GenericHandler };