From 37f39264fa1521fdda0f10806605b1946c28208c Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sat, 2 Jan 2021 21:23:50 +0100
Subject: [PATCH] =?UTF-8?q?web.table:=20Podpora=20pro=20streamov=C3=A1n?=
=?UTF-8?q?=C3=AD=20exportu=20tabulek?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Table.rows může být cokoliv iterovatelného, z čeho padají řádky v podobě
slovníků, tedy i generátor.
Funkce send_as jde zavolat se streaming=True a pak odpověď streamuje.
To nicméně není default, protože je hezké, aby krátké odpovědi měly
Content-Length.
Také jsem vylepšil definici sloupečků, aby pouze key byl povinný
a vše ostatní defaultovalo.
---
mo/web/table.py | 49 ++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 40 insertions(+), 9 deletions(-)
diff --git a/mo/web/table.py b/mo/web/table.py
index a6d08b8f..c1e6a8f8 100644
--- a/mo/web/table.py
+++ b/mo/web/table.py
@@ -4,7 +4,7 @@ from flask import Response, url_for
from html import escape
import io
from markupsafe import Markup
-from typing import Sequence, Optional
+from typing import Sequence, Optional, Iterable
import werkzeug.exceptions
import mo.csv
@@ -16,7 +16,12 @@ from mo.web import app
class Column:
key: str # Jméno klíče ve slovnících
name: str # Název v hlavičce CSV
- title: Optional[str] # Titulek v HTML tabulkách
+ title: str # Titulek v HTML tabulkách
+
+ def __init__(self, key: str, name: Optional[str] = None, title: Optional[str] = None):
+ self.key = key
+ self.name = name or key
+ self.title = title or self.name
class Cell:
@@ -46,10 +51,10 @@ class CellLink(Cell):
class Table:
columns: Sequence[Column]
- rows: Sequence[dict]
+ rows: Iterable[dict]
filename: str
- def __init__(self, columns: Sequence[Column], rows: Sequence[dict], filename: str):
+ def __init__(self, columns: Sequence[Column], rows: Iterable[dict], filename: str):
self.columns = columns
self.rows = rows
self.filename = filename
@@ -58,7 +63,7 @@ class Table:
tab = ['<table class=data>', '<tr>']
for c in self.columns:
- tab.append(f'\t<th>{c.title or c.name}')
+ tab.append(f'\t<th>{c.title}')
for r in self.rows:
tab.append('<tr>')
@@ -87,19 +92,45 @@ class Table:
return out.getvalue()
- def send_as(self, format: str) -> Response:
+ def to_csv_stream(self, dialect: str) -> Iterable[str]:
+ out = io.StringIO()
+ writer = csv.writer(out, dialect=dialect)
+
+ header = [c.name for c in self.columns]
+ writer.writerow(header)
+
+ nrows = 0
+ for row in self.rows:
+ r = [row.get(c.key) for c in self.columns]
+ writer.writerow(r)
+
+ nrows += 1
+ if nrows >= 100:
+ yield out.getvalue()
+ out.seek(0)
+ out.truncate()
+ nrows = 0
+
+ yield out.getvalue()
+
+ def send_as(self, format: str, streaming: bool = False) -> Response:
if format == 'csv':
- out = self.to_csv(dialect='excel')
+ dialect = 'excel'
ctype = 'text/csv; charset=utf=8'
filename = self.filename + '.csv'
elif format == 'tsv':
- out = self.to_csv(dialect='tsv')
+ dialect = 'tsv'
ctype = 'text/tab-separated-values; charset=utf=8'
filename = self.filename + '.tsv'
else:
raise werkzeug.exceptions.NotFound()
- resp = app.make_response(out)
+ if streaming:
+ resp = Response(self.to_csv_stream(dialect=dialect))
+ else:
+ out = self.to_csv(dialect=dialect)
+ resp = app.make_response(out)
+
resp.content_type = ctype
resp.headers.add('Content-Disposition', f'attachment; filename={filename}')
return resp
--
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