A Better Django Admin ManyToMany Field Widget - javascript

I find the the Django Admin's default models.ManyToManyField widget to be cumbersome to use. It's the HTML select element and if you have a lot of Objects of the "other" model then it's quite impractical to actually find the "other" Objects you want to associate with "this" Object. And if you have a lot of objects of the "other" model it seems to even slows down the rendering of the Admin page.
I'm aware that I can build my own custom admin widget and apply it to my ManyToManyFields as I see fit, but are there any pre-built ones out there that I might use instead? In my dreams, I picture an auto-completing text input HTML widget. Is this even practical/possible to do in the Django admin framework?
Thanks.

Try using the filter_horizontal attribute on your admin class, for example:
class SomeModelAdmin(admin.ModelAdmin):
filter_horizontal = ('users',)
As mentioned in the documentation, "adding a ManyToManyField to this list will instead use a nifty unobtrusive JavaScript "filter" interface that allows searching within the options". filter_vertical does the same thing with a slightly different layout.

you could try using a raw id in the admin.
and the django docs:
http://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.raw_id_fields
if you are looking for something with auto-complete you might want to look at this as a starting point http://code.djangoproject.com/wiki/AutoCompleteSolutions
and finally a very simplistic inline Example:
models.py
class SomeModel(models.Model):
users = models.ManyToMany(User)
admin.py:
class SomeModelAdmin(admin.ModelAdmin):
raw_id_fields = ("users",)

I haven't actually played with it but I found this promising looking library referenced elsewhere.
It appears to do exactly what I wanted. Rather than loading the entire list of related objects (regardless of how many there are!) and presenting you with a picker to select a few of them, as filter_horizontal does, it presents a search/filter box and uses typeahead/autocomplete calls to retrieve results dynamically. This is great for the case where you have maybe 5000 users and want to pick 3 or 4 of them without waiting for 5k <option> elements to download and render.

This is an old question, but I want to add an answer here for people who find this just like I did: this situation is exactly what Django inline admins are for. Specifically, I use TabularInlines with raw id fields for many-to-many relations that have too many choices.
https://docs.djangoproject.com/en/2.1/ref/contrib/admin/#django.contrib.admin.TabularInline

You can try using Inline model as such -
class ManyToManyInline(TabularInline):
model = MyModel.many_to_many_field_name.through
raw_id_fields = ("render_raw_id_using_this",)
#register(MyModel)
class YourAdminClass(AnyBaseClass):
exclude = ("many_to_many_field_name",)
inlines = (ManyToManyInline,)
Now there is another issue I faced, finding "render_raw_id_using_this" field name.
So, I moved to shell and tried finding fields in through model as such -
In [1]: MyModel.many_to_many_field_name.through._meta.fields
Out [1]: (<django.db.models.fields.AutoField: id>, <django.db.models.fields.related.ForeignKey: fieldname1>, <django.db.models.fields.related.ForeignKey: fieldname2>)
So, I replaced render_raw_id_using_this with fieldname1
Similarly, you can use these field names to render raw id instead of drop down list in Inline model.

Related

Should I be using classes more than ID's when utilizing jQuery?

As a new web developer, I've been utilizing a lot of resources like StackOverflow to assist me in the learning and development process.
When using jQuery, all of the examples/responses that I've come across so far have only referenced classes, like so:
$('.yourClass')
as opposed to
$('#yourID')
Seeing that class referencing seems to be the trend (I honestly haven't found one author who writes a jQuery to an ID), are there any pitfalls I should be aware of for using ID's w/ jQuery or JS in general? Thanks!
EDIT 1: I'm aware that ID's are for single-items, classes are for accessing multiple items. I'm more interested in why I don't see any jQuery or JS examples referencing ID's. Thank you!
You would have to ask each author on a case-by-case basis, but generally when creating examples, the selector used doesn't matter; what's important is that you have a jQuery collection that you can call a method on.
By using a class selector in the example, you avoid newbie developers claiming that your plugin doesn't work when they try to use it on multiple elements with the same ID. Your example serves the purpose of showing how to use it on one or more elements, rather than just one.
People like to use classes because ids have to be unique across the whole page. When trying to make reusable, pluggable components, id's make this impossible to enforce.
Exception: the new web-components standard allows you to encapsulate ids to just your component.
An ID must be unique, you can have only one (like highlanders).
Classes are used to identify a "type" of object not a specific one.
An obligatory car analogy:
An ID is a license plate, unique to one specific thing #345-abc
The class relates to a whole category of things like .truck
Take note that a selector like $(".something") will actually be capable of producing a list of DOM elements; as it will select all DOM elements with the class of "something"
An ID selector $("#unique") will only ever return one element
Think of your HTML and CSS first.
Using Classes
If you have multiple HTML elements which all will look, feel and behave in the same way, then it is highly recommended to use a class to represent their style and behavior.
Example: rows or columns on a table, navigation buttons which animate in the exact same way, wrapper to images which have the same size throughout your website, etc.
Using ID's
However, if you have a unique HTML element which represents a particular thing or state or action in one of your pages, then that element should contain an id.
Example: pop up modal, a unique looking button, unique sections on your website which you can navigate to by their id, etc.
Then, you can use this behavior in your JavaScript and jQuery or whatever else you like to use.
Further reading
I know that you are fully aware of why we should use ID's or classes.
But the vast majority of answers that are given here, are thinking of a project context.
So, let's say editing a .js file that is linked to the scope of the entire project, the idea here is to be as reusable as possible, so that's why you'll see much more classes references than ID's. Is hard to maintain a project js file that makes reference to different ID's that are abroad the project.
Same thing will apply to css.
I hope the answer is enough, be free to post a comment or suggestions. :-)

Instantiating Objects Dynamically (Mistic Query Builder)

I'm new to JavaScript, focusing primarily on Java/PHP development. The JS applications I've built in the past have been pretty hackish, untestable, and unextensible.
I'm now trying to create an application that interfaces with data in a more appropriate manner. Basically I'm building a user interface for creating rules/actions that our support team and end users can access. The logic for the application contains a lot of Boolean and logical operators and just requires that some arbitrary set of conditions be met, and then will apply certain actions.
So, I've pretty much settled on a query builder type of application, and I love Mistic's work. Unfortunately, we don't have a Node.js server. So, I've set about finding ways to make this work with vanilla JS/jQuery. One iteration used Knockout.js. However, I found that API to be difficult to work with.
Now, I found this JSFiddle, which uses Mistic's work in a standalone version. I'd prefer to use this, but one thing I can't quite piece together is how to create multiple Query Builders dynamically. (Rules will appear in a table as shown in the second link, and I'll need an Add Row button).
$('#builder').queryBuilder({
sortable: true,
filters: [{
id: 'core_ID',
I've tried using the jQuery .each() function to create query builders bound to each element with a class of builder, but to no avail.
$.each('.builder').queryBuilder({
Can you guys show me how you'd go about dynamically creating new QueryBuilder objects as shown in the third link?
You use .builder as a selector, which means you select all elements that have a class="builder" attribute.
If that is so, then you should be able to just call $('.builder').queryBuilder(... and it should use all elements that have the class builder
EDIT: It does in fact do so. But the cakephp query builder doesn't allow it (for whatever reason). So you have to use each in the way that i describe.
if you want to use the each function, you would to it like that:
$( ".builder" ).each(function() {
$( this ).queryBuilder(...);
});
Explanation:
$(".builder") selects all elements that have a class="builder" attribute.
.each iterates over those elements. inside the function that is passed to each this contains the native DomElement (which is not a jquery element). Therefore $(this) gets the jQuery element for the DomElement and .queryBuilder is called on it.
you can call .queryBuilder on pretty much any jQuery element unless it is an array of elements (it will throw an error).
so basically any selector + each in the way I use it should work.
here is a working fiddle with your example using 4 querybuilders: http://jsfiddle.net/ap9gxo4L/42/

Web Page Javascript Objects

newbie question.
I've read some of the W3Schools, I also read a lot from other sources on the internet, however I can't find what I need, and I'm sure it's quite simple to you.
I'm using ASP.Net, and I want to add to my website, multiple items, which every item hold a picture, and some other information, including links. I'm pretty sure I don't need to write the code for every item in the HTML source, and I don't know exactly how to implement my this.
The basic idea is that my items will be imported from a Database that I create in visual studio, and I want to style my webpage so they would appear in a certain formation, I thought I might need to use Javascript or CSS for this, hope I'm not mistaken.
Javascript isn't some sort of magician that will render all your stuff on its own. However, you can use it to attach a template to every of your items.
What you have to do is :
Create a base HTML template for 1 of your item that can be applied to all of them
Create a Javascript function that will attach thoses CSS classes and HTML attributes to every element out of your DB (or you could use a templating frameork .. since there's a lot of them I'll let you look for it on Google. It's pretty easy to use)
On page load or whatever event you want to bind on, you call your function which will attach the CSS and HTML to every element out of your DB and will render it on your page
Enjoy what you've done.
I hope this helps. Good luck ! ;)

Including a custom js file on rails_admin dashboard

I am trying to include a custom js for a custom field that depends on a google maps control, I don't want to mix html and js on a partial file, however, up to now, it appears to be the way to go.
I have checked on the wiki and the only reference about including a custom js is here but it doesn't work.
I only want to be able to organize my javascripts as usual (at assets/javascripts/) and be able to interact with my rails_admin form views. Anyone has any idea on how this should be handled?
To restate: It sounds like you are trying to keep javascript code out of view (html/erb) files.
I can recommend one way you may wish to try.
If you look at the assets/javascript directory you can see the generated javascript files that are created per controller when you are scaffolding a resource.
These files are great for keeping all the code related to the controller context in. there is another file named application.js which is great to keep global javascript routines in.
If you put tags/fields on the elements which you wish to select to bind a javascript method to you are able to keep the methods focused on finding and binding fields sharing the tag.
example:
field you wish to interact with:
Blah
your_controller_name.js:
using jquery you should be able to select the span by the data tag ( you could stored extra infor. you can then also bind methods to the span.
$("span[data-interesting='hi there']").click(function() { console.log('someone clicked the span'); })
You could use a selector that is more general and do something useful to all the matching items.
Good luck!
James.

Javascript to enhance parameterized builds

The 'parameterized' builds in Jenkins are a bit limited. What if I want to have options that are related to one another?
For example 2 drop down lists. The selection from the first one controls the options in the second...
I don't really see any prescribed way to implement this, but a thought (and it feels super-hacky) would be to use javascript.
I've noticed you can enter <script> tags in the description attribute of parameters. Maybe a place to drop in some js? Also looks like prototype.js ships with the system.
So just how bad an idea is that, or is there a 'correct' way to do such a thing?
Check out the Active Choices Plugin it does exactly what you're looking for:
jenkins-ci.org - Active Choices Plugin
github.com - Active Choices Plugin
A Jenkins UI plugin for generating and rendering multiple value
options for a job parameter. The parameter options can be dynamically
generated from a Groovy script and can respond to changes in other job
parameters. The value options can be rendered as combo-boxes,
check-boxes, radio-buttons or rich HTML. Active Choices strives to
provide in a single plugin functionality found scattered among several
pre-existing plugins and some unique capabilities that are not
available yet.
The Active Choices plug-in provides additional Jenkins
parameter types that can be rendered as user interface (UI) controls
in job forms.
Once the plugin is installed three new parameter types become
available:
Active Choices Parameter
Active Choices Reactive Parameter
Active Choices Reactive Reference Parameter
Active Choices parameters allow users to select value(s) for a job parameter. Parameter values can be:
dynamically generated (using Groovy or a Scriptler script)
dynamically updated based on other UI parameters
multi-valued (can have more than one value)
rendered with a variety of UI controls, including dynamic HTML
I think you would be able to accomplish your listed example with the following dynamic parameters plugin without using javascript: https://github.com/tekante/Dynamic-Jenkins-Parameter/wiki. I have not personally used the plugin as a disclaimer. It looks like it will probably need to be built first based on what I have seen in the GitHub repo and the fact that I cannot find it on the official Jenkins plugin page.

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