There is a char field named json_field in Django Model. I am trying to iterate it from the view but it returns only one result as the return statement does. I am trying to figure it out how I can iterate json_field using yield.
the result that Model Object returns like:
id : 1
title : "Some Title"
json_field : [{"key":"value","key2":"value2"},{"key":"value","key2":"value2"}]
created : "Sat Oct 21 2017 14:00:53 GMT+0300 (+03)"
view.py
import json
def MyView(request):
model_query = MyModel.objects.all() or MyModel.objects.filter or exclude...
for item in model_query:
data_item = json.loads(item.json_field)
template = "template.html"
context = {"title":title, "data_item":data_item}
return render(request, template, context)
in template.html
{% for query_item in model_query %}
<table>
<thead>
<tr>
<th>{{ query_item.title }} - {{ query_item.created }}</th>
</tr>
</thead>
<tbody>
<tr>
<th>Some Heading </th>
<th>Some Heading </th>
</tr>
<!-- json data -->
{% for item in data_item %}
<tr>
<th>{{ item.key }}</th>
<td>{{ item.key2|floatformat:2 }}</td>
</tr>
{% endfor %}
<!-- json data -->
</thead>
</table><
{% endfor %}
Any help will be appreciated.
You can prepare dataset for you template.
# Fetch data from db as queryset of dicts
items = list(MyModel.objects.filter().values('title', 'created', 'json_field'))
# Decode json in-place
for item in items:
item['json_field'] = json.loads(item['json_field'])
context = {"title":title, "items": items}
Then interate through items inside your template:
{% for item in items %}
<table>
<thead>
<tr>
<th>{{ item.title }} - {{ item.created }}</th>
</tr>
</thead>
<tbody>
<tr>
<th>Some Heading </th>
<th>Some Heading </th>
</tr>
<!-- json data -->
{% for entry in item.json_field %}
<tr>
<th>{{ entry.key }}</th>
<td>{{ entry.key2|floatformat:2 }}</td>
</tr>
{% endfor %}
<!-- json data -->
</thead>
</table><
{% endfor %}
If you're using PostgreSQL, you can using JSONField. It uses the postgres's jsonb type, which is optimized for keeping a json serializable text.
If not, you still can use django-jsonfield. It almost gives the same functionality, even though some of the cool features of django's JSONField are not available (like this kind of lookups).
If none of these work for you, you can also implement your own JSONField by inheriting from CharField or TextField, and overriding some of the functions. This way, you won't need any of the logics of your field in your views.
Edit:
If you find changing your field hard or don't wanna do it for whatever reason, you can do this in your view:
for item in model_query:
item.loaded_json = json.loads(item.json_field)
then you can use it like a normal field in your template:
{% for query_item in model_query %}
{% for item in query_item.loaded_json %}
<span>{{ item.key }}</spam>
{% endfor %}
{% endfor %}
Hello!
The solution depends on your purposes.
Use comprehensions if you want to construct a list of json arrays:
data_items = [json.loads(item.json_field) for item in model_query]
... or generator of json array:
data_items = (json.loads(item.json_field) for item in model_query)
If you want to have a single array of json objects try this:
data_items = []
for item in model_query:
data_items.extend(json.loads(item.json_field))
Then you can use data_items as a template context.
A little tip: You can utilize JSONField at ORM level if you use PostgreSQL or MySQL. Consider this approach if you plan to make any filter queries on this field. As additional benefit JSON encoding/decoding will be out of box.
Thanks for updating your code!
Now I would restructure the json.load() list of dicts so you can use it. That is better style than mangling in the template.
concatenation is done by:
my_dict = dict()
for d in data_item
my_dict.update( d )
if you want to merge, check this thread:
How to merge two dictionaries in a single expression?
Related
I have data in the following (simplified) format:
MetricData(models.Model) with following fields: id, metric, date, facility, value
Now I want to create a table with the following format (execute the script to get the indented output table):
<table style="width:100%">
<tr>
<th>Date</th>
<th>Facility 1</th>
<th>Facility 2</th>
<th>Facility 3</th>
</tr>
<tr>
<td>03/2019</td>
<td>1.0</td>
<td>1.5</td>
<td>2.5</td>
</tr>
<tr>
<td>04/2019</td>
<td>1.5</td>
<td>1.5</td>
<td>2.0</td>
</tr>
</table>
As you can see, the number of facilities which is dynamic (new ones can be added to the database), are the column headers. For each facility there will be metric data in the database.
All examples from django-datatables-view I find are basically using models directly and one model entry is converted to one table row.
You can override the QuerySet for your model to get a list of headers:
class MetricDataQuerySet(models.QuerySet):
#property
def headers(self):
return [getattr(instance, self.model.header_column) for instance in self]
class MetricData(models.Model):
header_column = 'facility'
...
objects = MetricDataQuerySet.as_manager()
Notice I added the header_column, instead of hard coding facility in the QuerySet. This allows you to reuse the QuerySet for different models if you end up needing to.
Now, in your view:
def some_view(request):
...
context = {
'objects': MetricData.objects.all()
}
return render(request, 'some_template.html', context)
Finally, on some_template.html, you can do this:
<table>
<tr>
{% for header in objects.headers %}
<th>{{ header }}</th>
{% endfor %}
</tr>
{% for object in objects %}
<tr>
<td>row.date</td>
<td>row.metric</td>
<td>row.value</td>
</tr>
{% endfor %}
</table>
I got a view that receives a model and field the user passes via post (existing model and field inside the app of course) and makes a queryset filter on it, then i need to show in my template that result in a table (name fields must be the column headers) and their respective values.
This what i got so far trying to serialize the queryset result in order to make it easier to show in template:
Views.py:
from django.contrib.contenttypes.models import ContentType
class CommitteeReport(BaseView):
template_name = 'committee/committee_report.html'
def post(self, request, **kwargs):
myfield = request.POST['field'].lower()
my_model = request.POST['model'].lower()
queryset_obj = ContentType.objects.get(model = my_model).model_class().objects.filter(**{myfield:True})
return render(request, self.template_name,{
'requirements': queryset_obj,
})
And my template:
<div class="tab-pane active" id="tab_1">
<table class="datatable table table-striped table-hover" cellspacing="0">
<thead>
<tr>
{% for key in requirements %}
<th>{{ key.fields.name }}</th>
{% endfor %}
</tr>
</thead>
<tbody>
{% for item in requirements %}
<tr>{{ item.fields.value }}</tr>
{% endfor %}
</tbody>
</table>
</div>
Thing is, i don't get result or if i change the tag inside the template, i get the objects dictionary for every row.
Any idea of how to achieve what i need ?, thanks in advance.
You can get the list of fields of model using my_instance._meta.local_fields. So you could try this in your view before return:
if queryset_obj.exists():
fields = queryset_obj.first()._meta.local_fields
else:
fields = []
return render(request, self.template_name,{
'requirements': queryset_obj,
'fields': fields,
})
And then using the context variable fields in your template:
<table class="datatable table table-striped table-hover" cellspacing="0">
<thead>
<tr>
{% for field in fields %}
<th>{{ field.name }}</th>
{% endfor %}
</tr>
</thead>
<tbody>
{% for req in requirements %}
<tr>
{% for field in fields %}
<td>{{ req|lookup:field.name }}</td>
{% endfor %}
</tr>
{% endfor %}
</tbody>
</table>
where you define a custom lookup template filter to fetch the field value:
def lookup(model, attr):
if hasattr(model, attr):
return getattr(model, attr)
else:
return None
Note: I'm assuming that all requirements are the same class and have the same structure, so that requirements.0, the first object in the QuerySet, is used for making the headers of the table.
Note 2: I haven't tried this, you might move some of the work to the view and pass easier variables as context variables (e.g. the list of field names).
Note 3: I haven't added error handling, you should check if model is actually a Model instance for example.
Goal: {% for loop %} over a list (using Jinja2) and then print out results {{print}} in a HTML table using Bootstrap.
Problem: List is not printing in the template.
In the view_config, I used query .all() to return a list of all the assessment_results objects. They are returning... I confirmed this via terminal/print debugging. However, the for loop is not returning the values needed to populate a table; as read in Jinja2 tutorial. I don't think I need to use a for loop in the view_config as I have seen others do (see here), but I am new to this and am trying to figure out how these two programs (SQLALCHEMY and Jinja2) interact.
An example from the printout after using .all() mentioned above:
[<Assessment_Result(owner='<User(username ='baseball', firstname ='Jen', lastname ='See', email='girl#aol.com')>', assessment='<Assessment(name='Becoming a Leader', text='better decisions')>')>]
view_config code:
views.py
#view_config(route_name='assessment_results', request_method='GET', renderer='templates/assessment_results.jinja2')
def all_assessment_results(request):
with transaction.manager: # < --- THIS WAS THE ISSUE !
assessment_results = api.retrieve_assessment_results()
if not assessment_results:
raise HTTPNotFound()
return {'assessment_results': assessment_results}
Corresponding Jinja2 template using Bootstrap:
assessment_results.jinja2
<div class="container">
<table class="table table-hover">
<thead>
<tr>
<td> Assessment ID </td>
<td> Assessment </td>
<td> Owner </td>
</tr>
</thead>
<tbody>
<tr>
{% for x in assessment_results %}
<td>{{ x.assessments|e }}</td>
<td>{{ x.owners|e}}</td>
{% else %}
<td><em>no users found</em></td>
{% endfor %}
</tr>
</tbody>
</table>
</div>
You should look at the documentation
http://jinja.pocoo.org/docs/dev/templates/#for
You want to iterate over a dict, so consider using iteritems, itervalues or what ever you want.
Also note that your query will not return a dict, it will return a list or rows that matched.
I am also not sure if the for-else works in jinja. But you should avoid using that anyways.
I have a table in SQLite3 and I need to take nearly all the columns in the table and output them to a web page. For other pages I've used flask, but that has always been a case of passing 3 or 4 single value variables into the template.
I'm guessing it's something like passing either the cursor or, more likely, the rows from the cursor.fetchall() call into the template then a for row in rows loop in the template?
It should be:
<table>
{% for item in items %}
<tr>
<td>{{column1}}</td>
<td>{{column2}}</td>
<td>{{column3}}</td>
<td>{{column4}}</td>
</tr>
{% endfor %}
</table>
You need to follow the below:
[HTML]:
<table>
{% for item in items %}
<tr>
<td>{{item[0]}}</td>
<td>{{item[1]}}</td>
<td>{{item[2]}}</td>
<td>{{item[3]}}</td>
</td>
{% endfor %}
[python code]:
cursor = db.execute('SELECT column1,column2,column3,column4 FROM tablename')
items = cursor.fetchall()
return render_template('print_items.html', items=items)
Pass your data as some sort of collection, whether that's something like a dictionary in the official tutorial, or something simpler, like a tuple or list.
Yes, in your template, you'll use a {% for item in collection %} -> {% endfor %} loop to render out all of the data from your database.
Example Python method:
#app.route('/print_items')
def print_items():
cursor = db.execute('SELECT column1,column2,column3,column4 FROM tablename')
return render_template('print_items.html', items=cursor.fetchall())
Example template section:
<table>
{% for item in items %}
<tr>
<td>column1</td>
<td>column2</td>
<td>column3</td>
<td>column4</td>
</td>
{% endfor %}
My issue is that I can't seem to translate the dictionary into a table here's the error:
Could not parse ["appid"] from 'game[''appid"]
HTML code:
<table>
<tr>
<th>Game ID</th>
<th>Game Name</th>
<th>Hours Played</th>
</tr>
{% for game in games %}
{# each game object is a dictionary with "appid", "name " and "playtime_forever" keys #}
<tr>
<td>{{ game["appid"] }}</td>
<td>{{game["name"]}}</td>
<td>{{ game["playtime_forever"] }}</td>
</tr>
</table>
views.py code:
~~~~ There's stuff here but it shouldn't be important. ~~~~
return render(request,'hackathon/SteamAPI.html', game)
When I run the server it shows:
game:
[{u'appid': 4000,
u'has_community_visible_stats': True,
u'img_icon_url': u'd9101cbeddcc4ff06c7fa1936c3f381b0bbf2e92',
u'img_logo_url': u'dca12980667e32ab072d79f5dbe91884056a03a2',
u'name': u"Garry's Mod",
u'playtime_forever': 0},
Django templates do not support [] indexing. Instead of
game["appid"]
you should use
game.appid
The same applies for game.name and game.playtime_forever
As an unrelated note, you should also close your for loop:
</tr>
{% endfor %}
</table>
Dictionary should be accessed this way in Django Templates.
choices = {'key1':'val1', 'key2':'val2'}
<ul>
{% for key, value in choices.items %}
<li>{{key}} - {{value}}</li>
{% endfor %}
</ul>