Develop Reference

How do I send Django object as parameter in Javascript?

So as mention in title, I'm trying to send my Django object to JavaScript so I can massage it in the front end. Let me show you the code (simplified).
views.py
def main_page(request):
contents = Contents.objects.all()
context = {
'contents' : contents
}
return render(request, 'main/home.html', context)
template
{% for u in all_ans_us_paginated %}
<div class="row">
<div class="col">
<div class="" id="{{u.id}}" onclick="DetailModal('{{u}}')">
</div>
</div>
</div>
{% endfor %}
...
<script>
function DetailModal(u) {
console.log('{{u.author}}');
console.log('{{u.body}}');
}
</script>
My intention is to show a modal when the click event is triggered. But putting the modal part aside, I can't pass data as parameter to JavaScript.
*I don't want to make any changes in the python code. Is it possible to do it only with HTML and JavaScript?
**JSON.parse(u) won't work, because u is string.

IN DJANGO
from django.shortcuts import render
from json import dumps
def send_dictionary(request):
# create data dictionary
dataDictionary = {
'hello': 'World',
'geeks': 'forgeeks',
'ABC': 123,
456: 'abc',
14000605: 1,
'list': ['geeks', 4, 'geeks'],
'dictionary': {'you': 'can', 'send': 'anything', 3: 1}
}
# dump data
dataJSON = dumps(dataDictionary)
return render(request, 'main / app.js', {'data': dataJSON})
IN JAVASCRIPT
app.js file :
var data = JSON.parse("{{data|escapejs}}");
for(var x in data){
// Write What You Want Here
}
if you want a clean view of the code use this way because javaScript considers dictionaries as separate objects
dataDictionary = [
["Laugh", "Cry"],
["Even", "Odd"],
["Hot", "Cold"],
["Light", "Dark"],
["Opposite", "Same"],
["Far", "Near"],
["Give", "Take"],
["Night", "Day"],
["Import", "Export"],
["Hard", "Easy"],
["Never", "Always"],
["Late", "Early"],
["Less", "More"],
["Male", "Female"],
["Happiness", "Sadness"],
["Fast", "Slow"],
["Old", "Young"],
["Boy", "Girl"],
["Up", "Down"],
["Left", "Right"],
["Rich", "Poor"],
["Love", "Hate"],
["Inside", "Outside"],
["Bad", "Good"],
["Short", "Tall"],
]

Visual Studio Code: Jinja Curly Braces inline for Javascript variable

I am trying to get Jinja braces to stay in line for a javascript variable used in an apexchart.js call for a flask HTML page.
labels = JSON.parse({{ labels | tojson}})
data = JSON.parse({{ data | tojson}})
The problem I am having is that when I save the html the braces get formatted apart.
labels = JSON.parse({
{
labels | tojson
}
})
data = JSON.parse({
{
data | tojson
}
})
Is there away to stop Visual Studio Code from splitting the Jinja code apart?
Current Code Below:
<!-- language: lang-html -->
<!-- templates/index.html -->
{% extends 'base.html' %} {% block content %}
<title>Dashboard | {{title}}</title>
<div class="flex h-screen justify-center">
<div id="chart" class="h-1/4 w-1/2 content-center"></div>
</div>
<script src="https://cdn.jsdelivr.net/npm/apexcharts"></script>
<script>
labels = JSON.parse({
{
labels | tojson
}
})
data = JSON.parse({
{
data | tojson
}
})
var options = {
colors: ['#01ca95'],
chart: {
type: 'bar'
},
dataLabels: {
enabled: false
},
series: [{
name: 'sales',
data: data
}],
xaxis: {
categories: labels
},
yaxis: {
labels: {
formatter: function(data) {
//Setup new Formatting class variable
var Formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD'
});
return Formatter.format(data);
}
}
},
}
var chart = new ApexCharts(document.querySelector("#chart"), options);
chart.render();
</script>
{% endblock content %}

how can I add a django array element into a js array using an if condition

I have a Django project with data being submitted by form , I am trying to use chart.js to display the data. I need to check whether an array exists() if so then add an item to 'labels' array in 'mycharts.js' . Heres what I have so far
django views.py
ing1 = request.POST.getlist('ingredients1')
ing2 = request.POST.getlist('ingredients2')
ing3 = request.POST.getlist('ingredients3')
( I've passed the above into my context )
mycharts.js
var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
type: 'bar',
data: {chart.js
labels: ['{{ing1.0}}', '{{ing2.0}}', {% if ing3|length > 1 %} '{{ing3.0}}', {% endif %}],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
(etc...)
if I take out the if statement inside of 'labels' array , then it shows the 'ing1' and 'ing2' headings , but I can't get it to work with this if statement , whats the correct way of doing it.

I put 'ing1, 'ing2' and 'ing3' into a list called 'title' inside my views , then put that list into the context , then did the following inside the chart.js script :
{% for item in title %} '{{ item }}', {% endfor %}
now it adds the correct data to the labels array.

Generate multiple line charts in Django with ChartJS

i'm working in Django, to draw some graph in function of my modules. ie: if i have 2 modules, i want 2 charts , if 8 modules, 8 charts.
Modules are integreted in a plugin. so i can list all modules found in a plugin. i did this in Django:
def plugin_graph(request, hub_uid, plugin_uid):
request.session['is_admin'] = True
hub = Hub.objects.get(mac=hub_uid)
fields = []
if request.method == 'GET':
if 'field' in request.GET:
fields.append(request.GET['field'])
plugin = Plugin.objects.get(uid=plugin_uid, hub=Hub.objects.get(mac=hub_uid))
#on recupere lensemble desmodules de ce plug
modules = plugin.get_modules_list()
#pour chak module, tracer son graph
for m in modules:
modules_list = {'uid':m.uid,
'name':m.name,
'version':m.version,
'type':m.type,
'time':m.last_time(),
'rssi':m.rssi(),
'status_icon':m.status_icon()}
module = Module.objects.get(uid=m.uid, plugin=Plugin.objects.get(uid=plugin_uid, hub=Hub.objects.get(mac=hub_uid)))
historic = sorted(ModuleDocument.objects.filter(module=module), key=getKey)
values = get_graph_values(historic=historic, dates=None, fields=fields)
print values
field = None if len(fields) < 1 else fields[0]
return render(request, "admin/graph2.html",
{
'values': values,
'hub': hub_uid,
'plugin': plugin_uid,
'uid': m.uid,
'module': module,
'fields': module.get_number_fields(),
'field': field,
'level': 'module',
}
)
After recovering all my modules i draw the charts like that in javascript:
<script>
var ctx = document.querySelector("#chart");
var data = JSON.parse('{{ values }}'.replace(/"/g, '"'));
var labels = [];
var values = [];
var beginAtZero = true;
for (obj in data) {
labels.push(data[obj].x);
values.push(data[obj].y);
if (data[obj].y < 0) {
beginAtZero = false;
}
}
var lineChart = new Chart(ctx, {
type: 'line',
data: {
labels: labels,
datasets: [{
label: "{{field}}",
data: values,
borderColor: '#97168F'
}]
},
options: {
scales: {
xAxes: [{
time: {
unit: 'day'
}
}],
yAxes: [{
ticks: {
beginAtZero:beginAtZero
}
}]
}
}
});
</script>
My problem is just one chart is printed. i would like to put it in a for loop to recuperate all data & labels of each module to draw normally all charts i want.
Thank u for your help

You need to utilise the forloop.counter method in the django template to dynamically name a number of items, otherwise the charts will just get overwritten each time and you are just left with the last chart. Its worth noting that I include this code in the block content not a specific js block.
In the example below, the items that are dynamically named are;
The container div
<div id = 'emg-{{forloop.counter}}'>
The canvas
<canvas id="myChart-{{forloop.counter}}">
The chart JS function name
var func_name = "container-{{forloop.counter}}";
func_name = new Chart(
document.getElementById('myChart-{{forloop.counter}}'),{
type: 'scatter',
I've included the full code below. I appreciate my example is different from your posted code, but it demonstrates the concept of dynamically creating certain elements.
{% for time, name_list, value_list, latitude_list, longitude_list, polyline_list in data %}
{% with forloop.counter as track_object_counter %}
<div id = 'emg-{{forloop.counter}}'>
{% for item in emg_data %}
{% if item.loop_id == track_object_counter %}
<div id = "emg-plot" style="height:15rem; padding-top: 1rem;">
<canvas id="myChart-{{forloop.counter}}">
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
<script>
var y_data = {{item.data|strip_apostrophe}}
var x_data = '{{item.name}}'
var func_name = "container-{{forloop.counter}}";
func_name = new Chart(
document.getElementById('myChart-{{forloop.counter}}'),{
type: 'scatter',
data: {
datasets: [{
showLine: true,
label: x_data,
data: y_data,
backgroundColor: 'rgba(141,49,123,0.7)',
borderWidth: 2,
borderColor: 'rgba(141,49,123,0.7)'
}],
},
});
</script>
</canvas>
</div>
{% endif %}
{% endfor %}
</div>
{% endwith %}
{% endfor %}

how to use symfony controller variables in frontend js?

Say I have a controller like this:
public function showAction(Request $request, $id, $context = array())
{
$url = $this->getPlayUrl($id, $context);
//some code here}
I want to use the variable $url in a frontend js file like this :
var html = '<iframe src=\''+ url +'\' name=\'viewerIframe\' id=\'viewerIframe\' width=\'100%\'allowfullscreen webkitallowfullscreen height=\'100%\' style=\'border:0px\'></iframe>';
How am I supposed to make this happen? For the code above ,it gave me 'undefined url' error.
Thank you.

Another option would be to have your template call a controller action (so you can pass parameters as required), for example, like this example for using highchart.js:
{% block javascripts %}
{{ parent() }}
<script src="/js/highcharts.js"></script>
<script src="/js/exporting.js"></script>
<script type="text/javascript">
{{ render(controller('AppBundle:Default:script')) }}
</script>
{% endblock %}
In the controller it looks like this:
public function scriptAction() {
$reports = $this->get('app.reports');
$chart = $reports->getDistsFYToDate();
return $this->render('Default/script.js.twig', array(
'chart' => $chart,
));
}
and script.js.twig looks like this:
$(document).ready(function () {
var options = {
chart: {
type: 'line'
},
title: {
text: 'Distributions, FY{{ chart.fy }} to date'
},
xAxis: {
categories: [{% for category in chart.categories %}{{category|raw}}{%endfor%}]
},
yAxis: {
title: {
text: 'Distributions'
}
},
series: {{ chart.series|raw }}
};
$('#linechart').highcharts(options);
})

Maybe it's better if you use HTML5 data attributes: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes

In you view add some script tags and assign a javascript vraible to the twig variable. Don't forget to quote the twig (if required).
Firstly, I would ensure that the $url always had a value;
return $this->render('MyWebBundle:Player:show.html.twig', array(
'file' => $file,
'url' => (empty($url)) ? '' : $url,
'context' => $context,
'player' => $player,
'agentInWhiteList' => $agentInWhiteList
));
Something like;
<script>
var jsVar = '{{ url }}';
var html = false;
if (jsVar.length > 0) {
html = '<iframe src=\''+ jsVar +'\' name=\'viewerIframe\' id=\'viewerIframe\' width=\'100%\'allowfullscreen webkitallowfullscreen height=\'100%\' style=\'border:0px\'></iframe>';
}
// test html !== false before using it
</script>