My Google search skills evidently aren't up to scratch, so I'm wondering if Django has the capability to dynamically update text displayed on the HTML page depending on what option is selected from a dropdown?
Or would I need to look into utilising another tool to help with this?
Apologies for the noob question as I'm still learning Python/Django.
This can only be achieved via frontend scripting, so JavaScript. Depending on what you are using in your templates, you might have a possibility to use that library or write javascript yourself.
I think the easiest is to write it yourself. You could do it in the following way:
Create <div id="?">...</div> and populate with relevant text for all your options (change id="?" appropriately)
Show only the default one and hide the other
if you are using bootstrap[345] you can apply classes (d-none vs d-block)
write your own javascript
Then tie a "click" on the dropdown method to the activation of corresponding <div>
With the amount of information you supplied us with, this is the most I can suggest to you. I hope I interpreted your question correctly.
Related
First off, I am very new to programming and I have a relatively basic understanding of python, and average understanding of html.
Using what I know in python, I am trying to create a basic strategy game, a bit like the likes of Age of Empires, or Command and Conquer, based on collecting resources and using it to build things, except using a simple text or button-clicking type interface. I can do a text interface fine, but its a bit boring, and I would like to use some images. I have had a 1 hour lecture on tkinter, but I have tried and failed to make anything remotely 'usable' from it. What I can do, is make decent looking html pages which would serve my purpose very well.
What I am wondering is if there is a simple way of executing python functions and calling/displaying python variables through a html page? The python functions do all the logic and present variables which represent current resource levels, production, storage capability, levels of buildings, etc. At the most basic level all I need is a way of displaying these variables, and having buttons which execute a function to say, upgrade a building, which recalculates production and all that, and returns the new set of values.
As a really simple example:
<p> Wheat production: *python integer representing production*</p>
<button type="button" onclick="*execute python variable*">Upgrade Wheat</button>
There would also, I imagine, be a need to somehow update the variables which are changed on the html page. So the button executes a function to upgrade wheat production, python now has a new value for the wheat production variable, and this needs to be updated on the page, whether this is automatic, or by some other method. I guess the simple way would be if pressing the button could also reload the page, but that seems a little clumsy.
Does anyone know of a simple way of doing this? Or perhaps a python library which might help me here?
Yes, there is a way of doing this.
There are two approaches to this. One is to have all the work done on the server, the other approach is to use Javascript.
The first approach is this: write a python script that generates your HTML. If you use Django, you will get a lot of work done for you, but you will also get a lot of stuff you don't want. Django does have a built-in template language. Django is beyond the scope of this answer. You will get to do exactly what you describe above; an example of a template might be <p> Wheat production: {{wheat_production}}</p> - your python code will set up a dict mydict={"wheat_production":10} and you will pass the name of your template file and the dict to a function which will spit out your page. You will also have to learn about HTML forms, if you haven't done so yet.
The other approach is to use Ajax - Javascript that, when your page is displayed (and, perhaps, when buttons are clicked, or at regular intervals) will send/receive some data to allow you to update your page. I suggest looking into JQuery to do some of the lifting for you. This means that you can update bits of the page without having to reload the entire thing. You will still have to write some code on the server to talk to the database, and send the output, usually as JSON, back to the client.
When writing this sort of thing, make sure all of your security is on the server side, and don't trust anything the user tells you. For example, if you store the number of gold pieces in a field on your form, it's going to take someone about 10 seconds to give themselves as much gold as they want. Similarly, if a player can sell a diamond for 20 gold pieces, make sure they have the diamond before giving them the gold pieces - you don't want to end up with a player with 1,000,000 gold pieces and negative a thousand diamonds. Javascript is 100% insecure, anything that Javascript can do, the player can also do.
Take a look at http://pyjs.org/
What is pyjs?
pyjs is a Rich Internet Application (RIA) Development Platform for
both Web and Desktop. With pyjs you can write your JavaScript-powered
web applications entirely in Python.
pyjs contains a Python-to-JavaScript compiler, an AJAX framework and a
Widget Set API. pyjs started life as a Python port of Google Web
Toolkit, the Java-to-JavaScript compiler.
You can compile Python programs to javascript, and also use their Python libraries to generate HTML. Here's an example from their getting started guide:
from pyjamas import Window
from pyjamas.ui import RootPanel, Button
def greet(sender):
Window.alert("Hello, AJAX!")
class Hello:
def onModuleLoad(self):
b = Button("Click me", greet)
RootPanel().add(b)
I am beginner in python and stackoverflow
I am going to make a better desplay using python. I have a ubuntu on beaglebord. I want to make a good display(It only desplays some datas interactively - It gives some output only, no input gui interaction is provided) using python. I here about pyqt. But I don't know is it ok to design a better dashboard in my case. Is it possible to connect with a minimal browser(like what do in ATM's) desplay using python. So that I can design it using HTML and CSS.
please help me
You can design your UI using HTML and CSS. You must use pyQT's QWebView control to display these html pages as below
dashboard = QWebView()
dashboard.load("dashboard.html")
dashboard.show()
So I have a python webapp on Google App Engine and am using the jinja2 template engine. I have a lot of text on the site that I want to update regularly, such as news sections and updates about the site.
What is the most efficient way to go about doing this? Clearly the simplest short-term solution and what I am currently doing is just to change the HTML but I would like to give others access to this without giving them access to the server side of things.
Should I just bite the bullet and write a interface on an admin page that allows users to edit it and then the server takes this and renders it in the News section? Any suggestions or tips would be great!
What you are thinking about, and moving toward (whether you know it or not) is called a content management system.
Most of them store content in a database and provide a user interface to allow editing it, just as you're designing.
Perhaps you could use off-the-shelf parts? I don't know exactly which ones are appengine-based, but this is a very common task and I'm sure you'll save time by using others' work.
I have created a very basic jinja CMS to maintain Jinja (page) blocks. You can find it here: https://codereview.stackexchange.com/questions/5965/review-request-jinja-cms-for-energiekantoor-nl-on-google-app-engine
I'm exploring many technologies, but I would like your input on which web framework would make this the easiest/ most possible. I'm currently looking to JSP/JSF/Primefaces, but I'm not sure if that is capable of this app.
Here's a basic description of the app:
Users log in with their username and password (maybe I can somehow incorporate OPENID)?
With a really nice UI, they will be presented a large list of questions specific to a certain category, for example, "Cooking". (I will manually compile this list and make it available.)
When they click on any of these questions, a little input box opens up below it to allow the user to put in a link/URL.
If the link they enter has the same question on that webpage the URL points to, they will be awarded one point. This question then disappears and gets added to a different page that has a list of all correctly linked questions.
On the right side of the screen, there will be a leaderboard with the usernames of the people with the top ten points.
The idea is relatively simple - to be able to compile links to external websites for specific questions by allowing many people to contribute.
I know I can build the UI easily with Primefaces. [B]What I'm not sure is if JSP/JSF gives the ability to parse HTML at a certain URL to see if it contains words.[/B] I can do this with python easily by using urllib, but I can't use python for web GUI building (it is very difficult). What is the best approach?
Any help would be appreciated!!! Thanks!
The best approach is whatever is best for you. If Python isn't your strength but Java is, then use Java. If you're a Python expert and know little Java, use Python.
There are so many resources on the Internet supporting so many platforms that the decision really comes down to what works best for you.
For starters, forget about JSP/JSF. This is an old combination that had many problems. Please consider Facelets/JSF. Facelets is the default templating language in the current version of JSF, while JSP is there only for backwards compatibility.
What I'm not sure is if JSP/JSF gives the ability to parse HTML at a certain URL to see if it contains words.
Yes it does, although the actual fetching of data and parsing of its content will be done by plain Java code. This itself has nothing to do with the JSF APIs.
With JSF you create a Facelet containing your UI (input fields, buttons, etc). Then still using JSF you bind this to a so-called backing bean, which is primarily a normal Java class with only one or two JSF specific annotations applied to it (e.g. #ManagedBean).
When the user enters the URL and presses some button, JSF takes care of calling some action method in your Java class (backing bean). In this action method you now have access to the URL the user entered, and from here on plain Java coding starts and JSF specifics end. You can put the code that fetches the URL and does the parsing you require in a separate helper class (separation of concerns), or at your discretion directly in the backing bean. The choice is yours.
Incidentally we had a very junior programmer at our office use JSF for something not unlike what you are requesting here and he succeeded in doing it in a short time. It thus really isn't that hard ;)
No web technology does what you want. Parsing documents found at certain urls is out of the scope of building web interfaces.
However, each of Java's web technologies will give you, without limits, access to a rich and varied (if not too rich and much too varied) set of libraries and frameworks running on JVM. You could safely say that if there is a library for doing something, there will be a Java version available. Downloading and parsing a document will not require more than what is available in the standard library (unless you insist on injecting your dependencies or crosscutting your concerns), so no problems with doing your project with JSP, or JSF/Primefaces, or whatever.
Since you claim to already know Python, and since you will have to add some HTML/CSS anyway, I suggest you try Django. It's dead simple, has a set of OpenID plugins to choose from, will give you admin interface for free (so you can prime the pump with the first set of links).
We're rewriting a website used by one of our clients. The user traffic on it is very low, less than 100 unique visitors a week. It's basically just a nice interface to their data in our databases. It allows them to query and filter on different sets of data of theirs.
We're rewriting the site in Python, re-using the same Oracle database that the data is currently on. The current version is written in an old, old version of Coldfusion. One of the things that Coldfusion does well though is displays tons of database records on a single page. It's capable of displaying hundreds of thousands of rows at once without crashing the browser. It uses a Java applet, and it looks like the contents of the rows are perhaps compressed and passed in through the HTML or something. There is a large block of data in the HTML but it's not displayed - it's just rendered by the Java applet.
I've tried several JavaScript solutions but they all hinge on the fact that the data will be present in an HTML table or something along those lines. This causes browsers to freeze and run out of memory.
Does anyone know of any solutions to this situation? Our client loves the ability to scroll through all of this data without clicking a "next page" link.
I have done just what you are describing using the following (which works very well):
jQuery Datatables
It enables you to do 'fetch as you scroll' pagination, so you can disable the pagination arrows in favor of a 'forever' scroll.
Give a try with Jquery scroll.
Instead of image scroll , you need to have data scroll.
You should poulate data in the divs , instead of images.
http://www.smoothdivscroll.com/#quickdemo
It should work. I wish.
You gotta great client anyway :-)
Something related to your Q
http://www.9lessons.info/2009/07/load-data-while-scroll-with-jquery-php.html
http://api.jquery.com/scroll/
I'm using Open Rico's LiveGrid in a project to display a table with thousands of rows in a page as an endless scrolling table. It has been working really fine so far. The table requests data on demand when you scroll through the rows. The parameters are send as simple GET parameters and the response you have to create on the serverside is simple XML. It should be possible to implement a data backend for a Rico LiveGrid in Python.
Most people, in this case, would use a framework. The best documented and most popular framework in Python is Django. It has good database support (including Oracle), and you'll have the easiest time getting help using it since there's such an active Django community.
You can try some other frameworks, but if you're tied to Python I'd recommend Django.
Of course, Jython (if it's an option), would make your job very easy. You could take the existing Java framework you have and just use Jython to build a frontend (and continue to use your Java applet and Java classes and Java server).
The memory problem is an interesting one; I'd be curious to see what you come up with.
Have you tried jqGrid? It can be buggy at times, but overall it's one of the better JavaScript grids. It's fairly efficient in dealing with large datasets. It also has a feature whereby the grid retrieves data asynchronously in chunks, but still allows continuous scrolling. It just asks for more data as the user scrolls down to it.
I did something like this a while ago and successfully implemented YUI's data table combined with Django
http://developer.yahoo.com/yui/datatable/
This gives you column sorting, pagination, scrolling and so on. It also allows you to use a variety of data sources such as JSON or XML.