chore(python): implement get request with path parameters

Part of #16

Author: php-coder

examples/python/routes.py

@@ -1,7 +1,8 @@
 import os
 import psycopg2
+import psycopg2.extras
 
-from fastapi import APIRouter
+from fastapi import APIRouter, HTTPException
 
 router = APIRouter()
 
@@ -16,14 +17,17 @@ def get_v1_categories_count():
         port = 5432)
     try:
         with conn:
-            with conn.cursor() as cur:
+            with conn.cursor(cursor_factory = psycopg2.extras.RealDictCursor) as cur:
                 cur.execute('SELECT COUNT(*) AS counter FROM categories')
-                return cur.fetchone()[0]
+                result = cur.fetchone()
+                if result is None:
+                    raise HTTPException(status_code=404)
+                return result
     finally:
         conn.close()
 
 @router.get('/v1/collections/{collectionId}/categories/count')
-def get_v1_collections_collection_id_categories_count():
+def get_v1_collections_collection_id_categories_count(collectionId):
     conn = psycopg2.connect(
         database = os.getenv('DB_NAME'),
         user = os.getenv('DB_USER'),
@@ -32,9 +36,12 @@ def get_v1_collections_collection_id_categories_count():
         port = 5432)
     try:
         with conn:
-            with conn.cursor() as cur:
-                cur.execute('SELECT COUNT(DISTINCT s.category_id) AS counter FROM collections_series cs JOIN series s ON s.id = cs.series_id WHERE cs.collection_id = :collectionId')
-                return cur.fetchone()[0]
+            with conn.cursor(cursor_factory = psycopg2.extras.RealDictCursor) as cur:
+                cur.execute('SELECT COUNT(DISTINCT s.category_id) AS counter FROM collections_series cs JOIN series s ON s.id = cs.series_id WHERE cs.collection_id = %(collectionId)s', { "collectionId": collectionId })
+                result = cur.fetchone()
+                if result is None:
+                    raise HTTPException(status_code=404)
+                return result
     finally:
         conn.close()
 
@@ -47,7 +54,7 @@ def post_v1_categories():
     pass
 
 @router.get('/v1/categories/{categoryId}')
-def get_v1_categories_category_id():
+def get_v1_categories_category_id(categoryId):
     conn = psycopg2.connect(
         database = os.getenv('DB_NAME'),
         user = os.getenv('DB_USER'),
@@ -56,9 +63,12 @@ def get_v1_categories_category_id():
         port = 5432)
     try:
         with conn:
-            with conn.cursor() as cur:
-                cur.execute('SELECT id , name , name_ru , slug FROM categories WHERE id = :categoryId')
-                return cur.fetchone()[0]
+            with conn.cursor(cursor_factory = psycopg2.extras.RealDictCursor) as cur:
+                cur.execute('SELECT id , name , name_ru , slug FROM categories WHERE id = %(categoryId)s', { "categoryId": categoryId })
+                result = cur.fetchone()
+                if result is None:
+                    raise HTTPException(status_code=404)
+                return result
     finally:
         conn.close()
 

src/cli.js

@@ -164,6 +164,10 @@ const createEndpoints = async (destDir, lang, config) => {
             // "... WHERE id = :p.id" => [ "p.id" ]
             "extractParamsFromQuery": (query) => query.match(/(?<=:)[pb]\.\w+/g) || [],
 
+            // "/categories/:categoryId" => [ "categoryId" ]
+            // (used only with FastAPI)
+            "extractParamsFromPath": (query) => query.match(/(?<=:)\w+/g) || [],
+            
             // [ "p.page", "b.num" ] => '"page": req.params.page, "num": req.body.num'
             // (used only with Express)
             "formatParamsAsJavaScriptObject": (params) => {

src/templates/routes.py.ejs

@@ -1,7 +1,8 @@
 import os
 import psycopg2
+import psycopg2.extras
 
-from fastapi import APIRouter
+from fastapi import APIRouter, HTTPException
 
 router = APIRouter()
 
@@ -12,6 +13,12 @@ function generate_method_name(method, path) {
     return `${method}${name}`
 }
 
+// "INSERT INTO ... VALUES(:categoryId)" => "INSERT INTO ... VALUES(%(categoryId)s)"
+// See: https://www.psycopg.org/docs/usage.html#passing-parameters-to-sql-queries
+function convertToPsycopgNamedArguments(sql) {
+    return sql.replace(/:([_a-zA-Z]+)/g, '%($1)s')
+}
+
 // "/categories/:categoryId" => "/categories/{categoryId}"
 function convertToFastApiPath(path) {
     return path.replace(/:([_a-zA-Z]+)/g, '{$1}')
@@ -20,17 +27,23 @@ function convertToFastApiPath(path) {
 
 endpoints.forEach(function(endpoint) {
     const path = convertToFastApiPath(endpoint.path)
+    const paramsFromPath = extractParamsFromPath(endpoint.path)
 
     endpoint.methods.forEach(function(method) {
         const hasGetOne = method.name === 'get'
         const hasGetMany = method.name === 'get_list'
         const pythonMethodName = generate_method_name(method.name, path)
-        const sql = formatQuery(method.query)
+        const sql = convertToPsycopgNamedArguments(formatQuery(method.query))
+        const params = extractParamsFromQuery(method.query);
+        const formattedParams = params.length > 0
+            // [ "p.categoryId" ] => [ '"categoryId": categoryId' ]
+            ? ', { ' + params.map(param => param.substring(2)).map(param => `"${param}": ${param}`).join(', ') + ' }'
+            : ''
 
         if (hasGetOne || hasGetMany) {
 %>
 @router.get('<%- path %>')
-def <%- pythonMethodName %>():
+def <%- pythonMethodName %>(<%- paramsFromPath.join(', ') %>):
 <%          if (hasGetOne) { -%>
     conn = psycopg2.connect(
         database = os.getenv('DB_NAME'),
@@ -40,9 +53,12 @@ def <%- pythonMethodName %>():
         port = 5432)
     try:
         with conn:
-            with conn.cursor() as cur:
-                cur.execute('<%- sql %>')
-                return cur.fetchone()[0]
+            with conn.cursor(cursor_factory = psycopg2.extras.RealDictCursor) as cur:
+                cur.execute('<%- sql %>'<%- formattedParams %>)
+                result = cur.fetchone()
+                if result is None:
+                    raise HTTPException(status_code=404)
+                return result
     finally:
         conn.close()
 <%