I have some values on my controller that I want to pass to a javascript function in the view page.
In the controller, I have:
$f3->set('value', $value);
I can access the value on the view with {{#value}}, but how do I use(access) that value inside a javascript function on the view page??
<script type="text/javascript">
var value = XXX; //XXX in the {{#value}}, how do i access it in here???
</script>
It depends on the content stored inside $value.
If it's a basic string with no single/double quote inside, then the following code will work:
<script>
var value='{{ #value }}';
</script>
If it's an integer, the following code will work:
<script>
var value={{ #value }};
</script>
... although your IDE will probably report a syntax error.
If it's a float, the following code will work:
<script>
var value={{ str_replace(',', '.', #value) }};
</script>
... and your IDE will also probably report a syntax error. NB: the str_replace is for non-English locales that have decimal separator set to comma.
For all the rest (strings including quotes or arrays), you should convert your data to JSON, using one of the following techniques:
Technique 1:
Convert data to JSON and dump it to a JS object.
// controller.php (JSON encode)
$f3->set('data',json_encode($data));
<!-- template.html -->
<script>
var data={{ #data | raw }};
</script>
Pros: easy to use.
Cons: your IDE will report a syntax error + extra call to raw.
Technique 2:
Convert data to JSON, dump it to a JS string and parse it.
// controller.php (JSON encode + escape double quotes)
$f3->set('data',str_replace('\\u0022','\\\\u0022',
json_encode($data,JSON_HEX_APOS|JSON_HEX_QUOT)));
<!-- template.html -->
<script>
var data=JSON.parse('{{ #data | raw }}');
</script>
Cons: less easy to use + extra call to raw.
Pros: your IDE will not report any syntax error.
Technique 2bis:
Embed technique 2 in a F3 template filter.
// index.php
$tpl=Template::instance();
$tpl->filter('safejson',function($data){
$raw=\View::instance()->raw($data);
return str_replace('\\u0022','\\\\u0022',
json_encode($raw,JSON_HEX_APOS|JSON_HEX_QUOT));
});
<!-- template.html -->
<script>
var data=JSON.parse('{{ #data | safejson }}');
</script>
Pros: easy to use + your IDE will not report any syntax error.
Cons: extra call to raw.
Technique 3:
Convert data to JSON and embed it inside a DOM data- attribute.
// controller.php (JSON encode)
$f3->set('data',json_encode($data));
<!-- template.html -->
<div id="foo" data-json="{{ #data }}"></div>
<script>
var data=JSON.parse(document.getElementById('foo').dataset.json);
</script>
Pros: easy to use + your IDE will not report any syntax error + no extra call to raw.
I went a bit lazier than that.
I have my data in a dictionary file (F3). I load it in an input field at the bottom of my page and assign value via templating. I use Jquery (plain JS could be used to) to retrieve value.
Ex:
Dict data
'prf_conf'=>' Update your profile'
In my profile.html
`< input type = 'hidden' id ='prf_conf' value='{{#prf_conf}}' >`
//this loads data in whatever language on my page
JS
Confirm button text: (i used jquery-confirm.min.js in this example)
$.confirm({ title: $('#prf_conf').value()
… bit of gymnastic but worked well. No IDE issue…
Related
I have a Django template filter to retrieve dictionary items based on the key passed.
{% with data=dict_data|get_data:key %}
I have separately made a template_tag.py file which returns those items.
def get_domain_data(dictionary, key):
p = ast.literal_eval(dictionary)
return p[key]
# data being returned successfully
The issue is in passing the dynamic value of the key in the filter function.
<script>
var key_val = $('#input_id').val();
'{% with data=dict_data|get_domain_data:"'+key_val+'" %}'; //encountering error here
// rest of the code
'{% endwith %}';
</script>
If I hardcode a string value the entire operation works, but I am unable to use the JavaScript variable within the Django {% filter %} function.
As mentionned by Matt Ellen in a comment, the template code is executed on the server, then the generated result is sent to the browser which interprets the javascript parts - so this just can not work this way.
If your data dict is small enough and doesn't depend on javascipt user interactions (ie the javascript only reads it), then the solution is to serialize it to json (in the view itself or using a template filter - one might already exists FWIW), bind it to a javascript variable (in the template) and then let the javascript code use it as just any js object, ie (assuming a "jsonify" template filter):
<script>
var data_dict = {% data_dict|jsonify %};
function do_something() {
var key_val = $('#input_id').val();
var data = data_dict[key_val];
// rest of the code
}
// and you'll probably want to bind do_something to
// some js event handler
</script>
There is a similar issue at Get javascript variable's value in Django url template tag
Providing arg1 can be numeric and the reversed url doesn't contain other instances of the string /12345/ then you can use,
var url_mask = "{% url 'someview' arg1=12345 %}".replace(/12345/, tmp.toString());
As twig renders prior to any javascript, I'm running into what feels like a minor problem.
I need to set a variable in twig that I receive from JSON array, but I'm running into some problems, and I feel like this should be simple.
The data is fed to twig through symfony through a json array, and renders different messages depending on one element in the array; this part works without trouble.
I am able to print the output to the twig file; that works fine. The problem is that I'm having a hard time setting this to a twig variable so that I can use it in a few places.
This works fine:
$('.id').html(items[0].id);
and prints out to the twig here correctly:
<div class="id"></div>
I tried to do do something like this:
{% set requestid = '<div class="id"></div>' %}
{{ requestid }}
But as expected this simply rendered the HTML without the value.
I've been attempting to do something like this:
In the twig I have this:
{% set requestid = "request_holder" %}
{{ requestid }}
And in the jquery I have something like this:
var reqid = items[0].id;
reqid.replace("request_holder",reqid);
I also attempted something like this
var request_id = items[0].id;
window.location = request_id.replace("request_holder",request_id)
I feel like I'm missing a small piece.
**Edit for clarity **
The JSON array is being parsed by jquery.
I have the value of items[0].id
Additional edit here - to make it clear that I was confused: cleaning up a little so as not to send future readers down the wrong path
I believe[d] that the variable needs to be assigned in the javascript because the twig, which is php, is generated prior to the javascript.
I have been attempting to generate the twig in the javascript to no avail.
Here's what I have been attempting:
var requestitem = items[0].id;
$('.id').html("{% set requestId = " + requestitem + " %} <br/> {{ requestId }}");
This defines requestId as a string and is only returning + requestitem + onto the page.
When I attempt this (without the quotations)
var requestitem = items[0].id;
$('.id').html("{% set requestId = requestitem %} <br/> {{ requestId }}");
The twig does not recognize requestitem at all
I have attempted quoting out the twig brackets (e.g. "{" + "%" etc) but this of course only prints them onto the page and does not interpret them.
Twig processes on the server side. It takes variables and renders them as HTML and text. What gets displayed in the browser is just HTML / text / and Javascript. So your set requestid = "request_holder" and {{ requestid}} are just turned to text before they get to the browser.
After that, you have HTML and text on the front end which Javascript can interact with. If you need this id to change on the front end, it needs to be done in Javascript.
What are you using the id to do?
Thanks to the hint from ASOlivieri, I was able to realize what I was doing wrong. I'm putting this here in case anyone comes across this. I was simply looking for a way to create a variable and make it reusable (I didn't go into details as that seemed extraneous).
The data was only available in the JSON array, so any attempt to write it to a twig file would fail, quite simply because it had already been converted to HTML, so I was forced to find another solution,
I was able to keep the variable in a javascript as I had it before
var request_item = items[0].id;
As my original goal was to get the value to update the application through php, I simply needed to use this variable in an AJAX call, and pass it through the path I had wanted to use in twig. Here's a brief summary:
$('#mark-received').click(function()
{
var requestURL = "{{ path('my_path') }}";
jQuery.ajax({
url: requestURL,
type: 'GET',
data: {'id' : request_item},
success: function success(data, text, xhr){
$('#mark-received').addClass('hidden');
$('#received-canceled').removeClass('hidden');
$('header > .alerts').append( $('<div>Success Message</div>').addClass('alert alert-success'));
},
error: function error( xhr, status, err){
$('header > .alerts').append( $('<div>There is a problem. <div class="close">x</div></div>', err).addClass('alert alert-danger'));
}
})
});
I want to export a JSON string in python into a JS variable.
<script type="text/javascript">
var data = JSON.parse('{{ dataJSON }}');
console.log(data)
</script>
If I print the content of dataJSON I get: [{"offset":0,"total":1,"units":[{"village_id":37,"village_name":"Glim
But in the JS I get this: JSON.parse('[{"offset":0,"total":1,"units":[{"village_id":37
I use jinja2 template engine: http://jinja.pocoo.org/docs/dev/templates/#if
How can I fix that?
You need to mark the data as safe:
var data = {{ dataJSON|safe }};
This prevents it from being HTML-escaped. There is no need to use JSON.parse() this way; JSON is a valid JavaScript subset (at least insofar that the Python json module produces a valid subset).
Take into account that this doesn't make it JavaScript safe. You may want to adjust your JSON serialisation. If you are using Flask, a tojson filter is provided that ensures you get JavaScript-safe valid JSON:
var data = {{ data|tojson|safe }};
If you are not using Flask, post-process the JSON:
dataJSON = (json.dumps(data)
.replace(u'<', u'\\u003c')
.replace(u'>', u'\\u003e')
.replace(u'&', u'\\u0026')
.replace(u"'", u'\\u0027'))
This is Python code to produce a dataJSON value that can be safely used in HTML (including attribute values) and in JavaScript. Credit here goes to the Flask json.htmlsafe_dumps() function.
I want to export a JSON string in python into a JS variable.
<script type="text/javascript">
var data = JSON.parse('{{ dataJSON }}');
console.log(data)
</script>
If I print the content of dataJSON I get: [{"offset":0,"total":1,"units":[{"village_id":37,"village_name":"Glim
But in the JS I get this: JSON.parse('[{"offset":0,"total":1,"units":[{"village_id":37
I use jinja2 template engine: http://jinja.pocoo.org/docs/dev/templates/#if
How can I fix that?
You need to mark the data as safe:
var data = {{ dataJSON|safe }};
This prevents it from being HTML-escaped. There is no need to use JSON.parse() this way; JSON is a valid JavaScript subset (at least insofar that the Python json module produces a valid subset).
Take into account that this doesn't make it JavaScript safe. You may want to adjust your JSON serialisation. If you are using Flask, a tojson filter is provided that ensures you get JavaScript-safe valid JSON:
var data = {{ data|tojson|safe }};
If you are not using Flask, post-process the JSON:
dataJSON = (json.dumps(data)
.replace(u'<', u'\\u003c')
.replace(u'>', u'\\u003e')
.replace(u'&', u'\\u0026')
.replace(u"'", u'\\u0027'))
This is Python code to produce a dataJSON value that can be safely used in HTML (including attribute values) and in JavaScript. Credit here goes to the Flask json.htmlsafe_dumps() function.
I'm trying to pass a string of generated HTML from Python to Javascript. This is the simplified version of my view (using Pyramid framework).
#view_config(route_name='view_page', renderer='templates/page.jinja2', permission='view')
def view_cosmeceutical(request):
gen_html = markdown( ingredient.desc )
return dict(gen_html=gen_html)
From this thread, I saw that I can use {{ variable }} in Javascript too, so in my JS file, I have a function that attempts to change the innerHTML of the element with the id 'content-desc'. But all I'm getting is the string {{ genHTML }} instead of the actual variable containing the generated HTML.
function insertHTML() {
genHTML = '{{gen_html}}';
$('#content-desc').html(genHTML);
}
What am I doing wrong?
One good way to pass data and content from the server-side Python to JavaScript are
JSON embeds in HTML
Separate AJAX calls which serve JSON objects as application/json mime
For the embed approach, I would do somethibng along the lines to export data to the page template as JSON:
import json
gen_html = ...
javascript_data = json.dumps(dict(gen_html=gen_html))
return dict(javascript_data=javascript_data)
Then in the page template pass this to JavaScript global variables:
<script>
window.javascriptData = {{javascript_data}}; // Check need to escape HTML in your case
</script>
And then in JavaScript (keep preferably in a separate static .JS file):
$(document).ready(function() {
$('#content-desc').html(window.javascriptData.gen_html);
});
Also, I would not generate HTML for just passing it to JavaScript in the first place. Instead, I would pass raw data to JavaScript as JSON, and then generate HTML on the client-side from this data using client-side templating. This increases the complexity, but is more "clean" and flexible.
Example microtemplating engines for the client-side JavaScript:
DOM tree based JavaScript template engines