Two models:
category has_many: components
component belongs_to: category
The CATEGORY table defines variable names for different component types:
TYPE, VAR1, VAR2, VAR3, ...
Insulator, Voltage, Height, Material, ...
Current Transformer, Voltage, Ratio, Indoor, ...
In the NEW/EDIT views for the COMPONENT model, the user will first section the CATEGORY from a drop-down list. Based on the CATEGORY selected the column headings and field labels in the form(s) need to dynamically update to indicate the variable names associated with the selected CATEGORY.
i.e. IF the user selects CATEGORY = Insulator THEN the field labels for VAR1 ... VAR3 are Voltage, Height, Material, etc.
I assume this will be controlled in the _form.html.erb of a typical scaffold. I am looking for a recommended technique.
Thanks in advance any information.
Changing a form in response to a user selecting a different option in a select tag is probably best done by Javascript. This allows for execution on the client side, which will be faster than a trip back to the server.
I would recommend placing the different form fields inside a div tag that is hidden when the page loads. Each of the combinations of categories can be toggled to show in the form by binding to the Javscript onChange event on the select tag.
Here is more information on the select tag: http://www.w3schools.com/jsref/event_onchange.asp
Related
I am new to Django. I have a requirement where in based on the TypedChoiceField list selection some part of the form should be changed. Meaning for a particular selection I need some fields to be displayed on the webpage and for other selection I need some other fields to be displayed on the webpage.
If there is already a similar page existing, please point me to that page, it will help me a lot.
What I would do is set up a javascript static file (here's a tutorial) that hides and shows elements using the select method.
For example, if you had categories that each needed a different set of fields, you could put all your categories into a <select> element and then using some simple JS, display the desired fields:
$("#select_object").change(function () {
toggleFields();
});
In that case, #select_object would be that <select> element. Whenever it changes (the user selects something) it shows the fields you want.
How can I create an HTML form for which the user indicates a list of values drawn from a set of values? I can provide the form with the set of values to choose from.
The user is not indicating a set of values: the order of the selected values is important (the values are to be in descending priority order).
It would seem that the multiple attribute on a select element would be useful. But the select element does not seem to have any means for indicating the order of the selections, nor does the POST of the form guarantee ordering of the selected values.
I don't know exactly what you want but you can try the HTML5 sortable plugin, which is now hosted on github.
It's as simple as an <ul> with a list of elements and the user drag and drop the elements. With the callback
$('.sortable').sortable().bind('sortupdate', function() {
//Triggered when the user stopped sorting and the DOM position has changed.
});
And you can read the elements in the correct order and make that you want with it (save to DB, etc).
Alright, so I'm pretty new to Spring, but I was asked to resolve a bug. So in our application, we have a page that queries a database based on an id. However, not all entries are unique to the id. The id and date pair, on the other hand, do define unique entries.
So this page takes in an id. If there is only a single entry related to this id, everything works fine. However, if there are multiple entries, the page displays a radio button selection of the various dates that pertain to that id. We use something like:
< form:radiobutton id="loadDate" path="loadDate" value="${date}" label="${date}" />
Later on the same page, we want to display the data for that option. As part of it, we display the date of that selection:
< form:input id="aiLoadDate" path="loadDate" maxlength="22" size="22" class="readonly" readonly="true"/>
The problem is that when this happens, the variable (or bean? I'm not quite sure about Spring yet..) loadDate (a string) ends up being the same date twice, seperated with a comma. I'm guessing the problem here is the "path="loadDate"" that is common to both lines.
Instead of appending the date to the already existing one like a csv, I'd like it to overwrite the current entry intead. Is there a way to do this?
Spring is not the direct cause of your problem. When the elements of an HTML form are submitted, each element will appear in the request as a name=value pair. If two or more elements in the form have the same name (not id, name attribute) then those elements appear in the request as name=value,value (with one value per element with a duplicated name).
Option 1: stop using an input as a display element. Just display the date in a span (or div or paragraph or what ever). If you want the look of an input box (border, etc.) use CSS to create a class that has the look you want and attach the class to the span (or div or paragraph, etc) in which you display the date.
Option2: continue using an input as a display element. Disabled input elements are not added to the request when the form is submitted. in the form:imput set disabled="true".
I have the tables:
products, measures, colors
for each product I have related measures and colors.
Also I have a form with subtable where I need to show the table with columns:
[products] comboboxColumn, [measures] comboboxColumn and [colors] comboboxColumn.
The rows should be selected product, selected measure, selected color.
The question is:
how can I filter the measures ComboBox list for [measures] combobox-Cell (or colors ComboBox list) in my grid selected row, when I choosing a product from [products] combobox-Cell in that very selected row?
I suggest you use a continuous form rather than a datasheet. Create the combo and populate it with the relevant values in the current event and bind it to the correct field in your table. To avoid confusing the user, include a textbox bound to that field also. You can lock the textbox and label the combobox column something like "Choose Size". You can use conditional formatting to make the whole think prettier.
If for some reason it were mandatory to associate a <button> with more than one value, is there a good way to do it? For example ...
CSV:
<button value="Lancelot,Grail,blue">Answer</button>
JSON:
<button value="{'name':'Lancelot','quest':'Grail','color':'blue'}">Answer</button>
In the absence of a good way to do it, is there a traditional way?
Edit: another use case
Server M, the producer of the HTML, knows the user's current location and favorite genres, movie names, nearest theater, and next showtime. Server F knows how to query various 3rd party servers about how to get from point A to point B in order to arrive by time T. The user knows only the movie names: click Drag Me to Hell, and get the route. Server M could generate a form for each movie, with a single button showing the name of the movie and multiple hidden fields with the start and end locations and desired arrive-by time, but that would require a lot of repeated code. Every one of these one-button mini-forms would have the same method and action and the same hidden input field structure. Styling would be a collection of mini-forms rather than a collection of buttons, so FIELDSET and LEGEND are unavailable (because HTML forbids nested forms). Putting the parameters into the button's value attribute would be much tidier.
Well if you have to have a button element, why not use JavaScript to set a bogus property:
$('mybutton').compoundValue = { ... json ... };
and then reading the 'compoundValue's during form submit, etc.
Though really you might want to consider a group of checkboxes or some other form bits for what you're trying to accomplish.