From 9143dfa134fdd5ff9bf98d87907c0fc6b575169b Mon Sep 17 00:00:00 2001
From: Dan Howe <d.howe@wrl.unsw.edu.au>
Date: Fri, 30 Aug 2019 17:03:09 +1000
Subject: [PATCH] Store csv data as json object

---
 daqviewer/daqviewer.py | 46 +++++++++++++++++++++++++-----------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/daqviewer/daqviewer.py b/daqviewer/daqviewer.py
index db103d5..3ec5714 100644
--- a/daqviewer/daqviewer.py
+++ b/daqviewer/daqviewer.py
@@ -1,5 +1,6 @@
 import io
 import os
+import json
 import base64
 import datetime
 import numpy as np
@@ -38,6 +39,7 @@ app.layout = html.Div([
         # Only upload one file
         multiple=False),
     html.Div(id='output-data-upload'),
+    html.Div(id='json-storage', style={'display': 'none'}),
 ])
 
 
@@ -70,7 +72,6 @@ def parse_contents(contents, filename):
                              skiprows=[4])
 
     except Exception as e:
-        print(e)
         return html.Div(['There was an error processing this file.'])
 
     # Zero time series based on first 5s
@@ -79,12 +80,31 @@ def parse_contents(contents, filename):
     # Round dataframe to save disk space
     df = df.round(1)
 
+    return df.to_json(orient='table')
+
+
+@app.callback(Output('json-storage', 'children'), [
+    Input('upload-data', 'contents'),
+    Input('upload-data', 'filename'),
+])
+def update_output(contents, name):
+    if contents is not None:
+        return parse_contents(contents, name)
+
+
+@app.callback(Output('output-data-upload', 'children'),
+              [Input('json-storage', 'children')])
+def read_json_data(json_data):
+    if json_data is None:
+        return html.Div([])
+
+    df = pd.read_json(json_data, orient='table')
     ts = []
     for col in df.columns:
         trace = go.Scatter(x=df.index, y=df[col], name=col, opacity=0.8)
         ts.append(trace)
 
-    layout = {'title': basename, 'xaxis': {'rangeslider': {}}}
+    layout = {'title': 'basename', 'xaxis': {'rangeslider': {}}}
     graph_timeseries = dcc.Graph(id='time-series',
                                  figure={
                                      'data': ts,
@@ -150,25 +170,15 @@ def parse_contents(contents, filename):
         },
     )
 
-    return graph_timeseries, graph_energy, table_energy
+    elements = html.Div([
+        graph_timeseries, graph_energy, table_energy,
+        html.Div(id='datatable-row-ids-container')
+    ])
 
+    return elements
 
-@app.callback(Output('output-data-upload', 'children'), [
-    Input('upload-data', 'contents'),
-    Input('upload-data', 'filename'),
-])
-def update_output(contents, name):
-    if contents is not None:
-        graph_ts, graph_spec, table_spec = parse_contents(contents, name)
-        elements = html.Div([
-            graph_ts, graph_spec, table_spec,
-            html.Div(id='datatable-row-ids-container')
-        ])
 
-        return elements
-
-    else:
-        return html.Div([])
+#####
 
 
 def main():