From 8063657daf781d32ef7e9117fba6b5d0c83127e1 Mon Sep 17 00:00:00 2001
From: Vytor Calixto <vytorcalixto@gmail.com>
Date: Tue, 10 Jan 2017 10:04:39 -0200
Subject: [PATCH] Added a "query builder" middleware for fields
It uses a object to set the url fields accepted and it's values, parse the
fields and build the query with the values automagically
---
src/libs/middlewares/reqQueryFields.js | 167 +++++++++++++++++++++++++
1 file changed, 167 insertions(+)
create mode 100644 src/libs/middlewares/reqQueryFields.js
diff --git a/src/libs/middlewares/reqQueryFields.js b/src/libs/middlewares/reqQueryFields.js
new file mode 100644
index 00000000..10836590
--- /dev/null
+++ b/src/libs/middlewares/reqQueryFields.js
@@ -0,0 +1,167 @@
+const libs = `${process.cwd()}/libs`;
+
+const log = require(`${libs}/log`)(module);
+
+const parseParams = require(`${libs}/middlewares/parseParams`);
+
+const _ = require('lodash');
+
+class ReqQueryFields {
+ constructor(fields = {}, fieldValues = {}) {
+ // Parâmetros no campo query da requisição.
+ // Exemplo de field:
+ // {
+ // name: 'dims',
+ // field: true,
+ // where: false
+ // }
+ this.fields = fields;
+ this.fieldValues = fieldValues;
+ }
+
+ addField(field) {
+ // Parâmetro no campo query da requisição.
+ // Exemplo de field:
+ // {
+ // name: 'dims',
+ // field: true,
+ // where: false,
+ // fieldValues: {}
+ // }
+ if(typeof this.fields[field.name] === 'undefined') {
+ this.fields[field.name] = field;
+ }
+ return this;
+ }
+
+ addValue(fieldValue) {
+ // Array de valores aceitos pelo campo
+ // Exemplo de valor:
+ // {
+ // name: 'location',
+ // table: 'localizacao',
+ // tableField: 'descricao'
+ // resultField: 'location_name',
+ // where: {
+ // relation: '=',
+ // type: 'integer',
+ // field: 'id_localizacao',
+ // table: 'turma'
+ // },
+ // join: {
+ // primary: 'pk_localizacao_id',
+ // foreign: 'id_localizacao',
+ // foreignTable: 'turma'
+ // }
+ // }
+
+ if(typeof this.fieldValues[fieldValue.name] === 'undefined') {
+ this.fieldValues[fieldValue.name] = fieldValue;
+ }
+ return this;
+ }
+
+ parse() {
+ return (req, res, next) => {
+ Object.keys(this.fields).map((key, index) => {
+ let params = [];
+ let f = this.fields[key];
+ log.debug('f');
+ log.debug(f);
+ Object.keys(this.fieldValues).map((k, i) => {
+ let value = this.fieldValues[k];
+ log.debug('value');
+ log.debug(value);
+ params.push(value.name);
+ });
+ let queryField = f.name;
+ let arrayOfParams = params;
+ req[queryField] = {};
+ if (req.query[queryField]) {
+ const params = req.query[queryField].split(',');
+ // Temporary object to hold the params and it's values
+ const obj = {};
+ for (const param of params) {
+ // Get the key and the value - state:41 is key 'state' whith value 41.
+ // kv is then an array [key, value] or [key] if there is no value
+ const kv = param.split(':');
+ // Check if there is a value. If there isn't, assign true
+ obj[kv[0]] = (typeof kv[1] === 'undefined') ? true : kv[1];
+ // obj is now an object {kv[0]: kv[1]} ou {kv[0]: true}
+ }
+
+ // If the array exists and is not empty we intersect
+ if (typeof arrayOfParams !== 'undefined' && arrayOfParams.length > 0) {
+ // Intersect the keys of the obj with the array arrayOfParams
+ // The intersection array is assigned with the keys
+ const intersection = _.intersection(arrayOfParams, Object.keys(obj));
+ // This is a bit tricky...
+ // For each key in the intersection array we get it's value in the obj
+ // and assign it to the custom attribute in the req obj.
+ // For example: instersection => ["state"] so
+ // obj[intersection[i]] (with i=0) is obj["state"], that is 41
+ // and req[queryField]["state"] = 41
+ for (let i = 0; i < intersection.length; ++i) {
+ req[queryField][intersection[i]] = obj[intersection[i]];
+ }
+ req[queryField].size = intersection.length;
+ } else {
+ req[queryField] = obj;
+ req[queryField].size = Object.keys(obj).length;
+ }
+ }
+ });
+ next();
+ };
+ }
+
+ build() {
+ return (req, res, next) => {
+ Object.keys(this.fields).map((key, index) => {
+ let field = this.fields[key];
+ log.debug(field);
+ let param = req[field.name];
+ log.debug(param);
+ Object.keys(param).map((k, i) => {
+ let values = this.fieldValues;
+ log.debug(k);
+ if(typeof values[k] !== 'undefined') {
+ // Clonamos para não alterar
+ let value = _.clone(values[k]);
+ log.debug(value);
+ // Checa se não fizemos o join para este valor e se é necessário fazer
+ if(!value.hasJoined && typeof value.join !== 'undefined') {
+ let foreignTable = '';
+ if(value.join.foreignTable) foreignTable = value.join.foreignTable+'.';
+ // Fazemos o join
+ req.sql.join(value.table, null, foreignTable+value.join.foreign+'='+value.table+'.'+value.join.primary);
+ // Marcamos o join como feito para não ter problemas
+ value.hasJoined = true;
+ }
+ // Se o valor é um campo a ser incluÃdo no SELECT
+ if(typeof field.field !== 'undefined' && field.field) {
+ log.debug('SELECT');
+ req.sql.field(value.table+'.'+value.tableField, value.resultField || value.tableField)
+ .group(value.table+'.'+value.tableField)
+ .order(value.table+'.'+value.tableField);
+ }
+ // Se o valor é um campo para ser usado no WHERE
+ if(typeof field.where !== 'undefined' && field.where) {
+ log.debug('WHERE');
+ // Valor do where
+ let whereValue = param[k];
+ // Valor sempre vem como string, necessário fazer parse para o banco
+ if(value.where.type === 'integer') whereValue = parseInt(whereValue, 10);
+ if(value.where.type === 'double') whereValue = parseFloat(whereValue);
+ let tbl = value.where.table || value.table;
+ req.sql.where(tbl+'.'+value.where.field+' '+value.where.relation+' ?', whereValue);
+ }
+ }
+ });
+ });
+ next();
+ };
+ }
+}
+
+module.exports = ReqQueryFields;
--
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