I'm building a pyqt5 desktop interface where I'm using QWebEngineView to show a html file where I show a Leaflet map. This is working fine. The next step is to export all features the user added to the map. When I click on "Export Features" on the map nothing happen, but when I open the same html file on my Chromium web browser, the "Export feature" opens the download dialog fine.
PyQt5 script:
self.MainWindow.webMapViewer = QtWebEngineWidgets.QWebEngineView()
self.MainWindow.webPageLayout.addWidget(self.MainWindow.webMapViewer)
self.html_path = os.path.split(os.path.abspath(__file__))[0] + r'/html/test.html'
self.MainWindow.webMapViewer.load(QtCore.QUrl().fromLocalFile(self.html_path))
HTML:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
<title>FazMaraneyRGB_transparent_mosaic_group1</title>
<!-- Leaflet -->
<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.css" />
<script src="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.js"></script>
<!-- Leaflet.draw -->
<link rel="stylesheet" href="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.css" />
<script src="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.js"></script>
<!-- Leaflet Ajax -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet-ajax/2.1.0/leaflet.ajax.min.js"></script>
<!-- Leaflet Measument -->
<link rel="stylesheet" href="http://ljagis.github.io/leaflet-measure/leaflet-measure.css" />
<script src="http://ljagis.github.io/leaflet-measure/leaflet-measure.min.js"></script>
<style>
body { margin:0; padding:0; }
body, table, tr, td, th, div, h1, h2, input { font-family: "Calibri", "Trebuchet MS", "Ubuntu", Serif; font-size: 11pt; }
#map { position:absolute; top:0; bottom:0; width:100%; } /* full size */
.ctl {
padding: 2px 10px 2px 10px;
background: white;
background: rgba(255,255,255,0.9);
box-shadow: 0 0 15px rgba(0,0,0,0.2);
border-radius: 5px;
text-align: right;
}
.title {
font-size: 18pt;
font-weight: bold;
}
.src {
font-size: 10pt;
}
#delete, #export {
position: absolute;
top:100px;
right:10px;
z-index:100;
background:white;
color:black;
padding:6px;
border-radius:4px;
font-family: 'Helvetica Neue';
cursor: pointer;
font-size:12px;
text-decoration:none;
}
#export {
top:130px;
}
</style>
</head>
<body>
<div id='map'></div>
<div id='delete'>Delete Features</div>
<a href='#' id='export'>Export Features</a>
<script>
/* **** Leaflet **** */
// Base layers
// .. OpenStreetMap
var osm = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {attribution: '© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'});
// .. White background
var white = L.tileLayer("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEAAQMAAABmvDolAAAAA1BMVEX///+nxBvIAAAAH0lEQVQYGe3BAQ0AAADCIPunfg43YAAAAAAAAAAA5wIhAAAB9aK9BAAAAABJRU5ErkJggg==");
// Overlay layers (TMS)
var lyr1 = L.tileLayer('./tiles/{z}/{x}/{y}.png', {tms: true, maxZoom: 22, opacity: 0.9, attribution: ""});
// Map
var map = L.map('map', {
measureControl: true,
center: [-18.3604868606589, -52.694255477616245],
zoom: 22,
minZoom: 0,
maxZoom: 22,
layers: [osm]
});
lyr1.addTo(map);
//Geojson Layers
var basemaps = {"OpenStreetMap": osm, "Without background": white}
var overlaymaps = {"Layer 1": lyr1}
// Title
var title = L.control();
title.onAdd = function(map) {
this._div = L.DomUtil.create('div', 'ctl title');
this.update();
return this._div;
};
title.update = function(props) {
this._div.innerHTML = "FazMaraneyRGB_transparent_mosaic_group1";
};
title.addTo(map);
// Note
var src = 'Generated by Hawkit';
var title = L.control({position: 'bottomleft'});
title.onAdd = function(map) {
this._div = L.DomUtil.create('div', 'ctl src');
this.update();
return this._div;
};
title.update = function(props) {
this._div.innerHTML = src;
};
title.addTo(map);
var featureGroup = L.featureGroup().addTo(map);
var drawControl = new L.Control.Draw({
edit: {
featureGroup: featureGroup
}
}).addTo(map);
map.on('draw:created', function(e) {
// Each time a feaute is created, it's added to the over arching feature group
featureGroup.addLayer(e.layer);
});
// on click, clear all layers
document.getElementById('delete').onclick = function(e) {
featureGroup.clearLayers();
}
document.getElementById('export').onclick = function(e) {
// Extract GeoJson from featureGroup
var data = featureGroup.toGeoJSON();
// Stringify the GeoJson
var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));
// Create export
document.getElementById('export').setAttribute('href', 'data:' + convertedData);
document.getElementById('export').setAttribute('download','data.geojson');
}
// Add base layers
L.control.layers(basemaps, overlaymaps, {collapsed: true}).addTo(map);
// Fit to overlay bounds (SW and NE points with (lat, lon))
map.fitBounds([[-18.36827062251916, -52.6871074784942], [-18.35270287637126, -52.7014028427423]]);
</script>
</body>
</html>
That popup window is generated by the browser, in the case of QWebEngine we must create it. To start, the signal indicating the download must be detected, and this signal is downloadRequested from the QWebEngineProfile. That signal sends us a QWebEngineDownloadItem object that handles the download, in it we create a dialog window with the help of QFileDialog. For this case we will create a custom QWebEnginePage as shown below:
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
<title>FazMaraneyRGB_transparent_mosaic_group1</title>
<!-- Leaflet -->
<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.css" />
<script src="http://cdn.leafletjs.com/leaflet-0.7.5/leaflet.js"></script>
<!-- Leaflet.draw -->
<link rel="stylesheet" href="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.css" />
<script src="https://unpkg.com/leaflet-draw@0.4.1/dist/leaflet.draw.js"></script>
<!-- Leaflet Ajax -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet-ajax/2.1.0/leaflet.ajax.min.js"></script>
<!-- Leaflet Measument -->
<link rel="stylesheet" href="http://ljagis.github.io/leaflet-measure/leaflet-measure.css" />
<script src="http://ljagis.github.io/leaflet-measure/leaflet-measure.min.js"></script>
<style>
body {
margin: 0;
padding: 0;
}
body,
table,
tr,
td,
th,
div,
h1,
h2,
input {
font-family: "Calibri", "Trebuchet MS", "Ubuntu", Serif;
font-size: 11pt;
}
#map {
position: absolute;
top: 0;
bottom: 0;
width: 100%;
}
/* full size */
.ctl {
padding: 2px 10px 2px 10px;
background: white;
background: rgba(255, 255, 255, 0.9);
box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
border-radius: 5px;
text-align: right;
}
.title {
font-size: 18pt;
font-weight: bold;
}
.src {
font-size: 10pt;
}
#delete,
#export {
position: absolute;
top: 100px;
right: 10px;
z-index: 100;
background: white;
color: black;
padding: 6px;
border-radius: 4px;
font-family: 'Helvetica Neue';
cursor: pointer;
font-size: 12px;
text-decoration: none;
}
#export {
top: 130px;
}
</style>
</head>
<body>
<div id='map'></div>
<div id='delete'>Delete Features</div>
<a href='#' id='export'>Export Features</a>
<script>
/* **** Leaflet **** */
// Base layers
// .. OpenStreetMap
var osm = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
attribution: '© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
});
// .. White background
var white = L.tileLayer("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEAAQMAAABmvDolAAAAA1BMVEX///+nxBvIAAAAH0lEQVQYGe3BAQ0AAADCIPunfg43YAAAAAAAAAAA5wIhAAAB9aK9BAAAAABJRU5ErkJggg==");
// Overlay layers (TMS)
var lyr1 = L.tileLayer('./tiles/{z}/{x}/{y}.png', {
tms: true,
maxZoom: 22,
opacity: 0.9,
attribution: ""
});
// Map
var map = L.map('map', {
measureControl: true,
center: [-18.3604868606589, -52.694255477616245],
zoom: 22,
minZoom: 0,
maxZoom: 22,
layers: [osm]
});
lyr1.addTo(map);
//Geojson Layers
var basemaps = {
"OpenStreetMap": osm,
"Without background": white
}
var overlaymaps = {
"Layer 1": lyr1
}
// Title
var title = L.control();
title.onAdd = function(map) {
this._div = L.DomUtil.create('div', 'ctl title');
this.update();
return this._div;
};
title.update = function(props) {
this._div.innerHTML = "FazMaraneyRGB_transparent_mosaic_group1";
};
title.addTo(map);
// Note
var src = 'Generated by Hawkit';
var title = L.control({
position: 'bottomleft'
});
title.onAdd = function(map) {
this._div = L.DomUtil.create('div', 'ctl src');
this.update();
return this._div;
};
title.update = function(props) {
this._div.innerHTML = src;
};
title.addTo(map);
var featureGroup = L.featureGroup().addTo(map);
var drawControl = new L.Control.Draw({
edit: {
featureGroup: featureGroup
}
}).addTo(map);
map.on('draw:created', function(e) {
// Each time a feaute is created, it's added to the over arching feature group
featureGroup.addLayer(e.layer);
});
// on click, clear all layers
document.getElementById('delete').onclick = function(e) {
featureGroup.clearLayers();
}
document.getElementById('export').onclick = function(e) {
// Extract GeoJson from featureGroup
var data = featureGroup.toGeoJSON();
// Stringify the GeoJson
var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));
// Create export
document.getElementById('export').setAttribute('href', 'data:' + convertedData);
document.getElementById('export').setAttribute('download', 'data.geojson');
}
// Add base layers
L.control.layers(basemaps, overlaymaps, {
collapsed: true
}).addTo(map);
// Fit to overlay bounds (SW and NE points with (lat, lon))
map.fitBounds([
[-18.36827062251916, -52.6871074784942],
[-18.35270287637126, -52.7014028427423]
]);
</script>
</body>
</html>main.py
from PyQt5 import QtWebEngineWidgets, QtWidgets, QtCore
class WebEnginePage(QtWebEngineWidgets.QWebEnginePage):
def __init__(self, *args, **kwargs):
QtWebEngineWidgets.QWebEnginePage.__init__(self, *args, **kwargs)
self.profile().downloadRequested.connect(self.on_downloadRequested)
@QtCore.pyqtSlot(QtWebEngineWidgets.QWebEngineDownloadItem)
def on_downloadRequested(self, download):
old_path = download.path()
suffix = QtCore.QFileInfo(old_path).suffix()
path, _ = QtWidgets.QFileDialog.getSaveFileName(self.view(), "Save File", old_path, "*."+suffix)
if path:
download.setPath(path)
download.accept()
if __name__ == '__main__':
import sys
sys.argv.append("--remote-debugging-port=8000")
sys.argv.append("--disable-web-security")
app = QtWidgets.QApplication(sys.argv)
view = QtWebEngineWidgets.QWebEngineView()
page = WebEnginePage(view)
view.setPage(page)
path = QtCore.QDir.current().filePath("index.html")
view.load(QtCore.QUrl.fromLocalFile(path))
view.show()
sys.exit(app.exec_())
In your case:
self.MainWindow.webMapViewer = QtWebEngineWidgets.QWebEngineView()
self.MainWindow.webPageLayout.addWidget(self.MainWindow.webMapViewer)
page = WebEnginePage(self.MainWindow.webMapViewer) # create page
self.MainWindow.webMapViewer.setPage(page) # set page
self.html_path = os.path.split(os.path.abspath(__file__))[0] + r'/html/test.html'
self.MainWindow.webMapViewer.load(QtCore.QUrl().fromLocalFile(self.html_path))
Plus:
If you want to set a defined route use the following:
@QtCore.pyqtSlot(QtWebEngineWidgets.QWebEngineDownloadItem)
def on_downloadRequested(self, download):
directory = "/path/of/directory"
filename = QtCore.QFileInfo(download.path()).fileName()
download.setPath(QtCore.QDir(directory).filePath(filename))
download.accept()