大约有 44,000 项符合查询结果（耗时：0.0391秒） [XML]
differentiate null=True, blank=True in django
...mines whether the field will be required in forms. This includes the admin and your custom forms. If blank=True then the field will not be required, whereas if it's False the field cannot be blank.
The combo of the two is so frequent because typically if you're going to allow a field to be blank in...
How do I select the parent form based on which submit button is clicked?
...one hidden variable that's different). A user will only fill in one form, and I'd like to validate/etc all the forms with only one JS script.
...
When should I use Inline vs. External Javascript?
...l scripts or write them inline with the html code, in terms of performance and ease of maintenance.
18 Answers
...
What is %2C in a URL?
I'm trying to understand the structure of a URL, and I'm seeing a lot of %2C . I'm guessing this is a result of some encoding. What does that stand for?
...
Laravel Eloquent Sum of relation's column
I've been working on a shoppingcart application and now I've come to the following issue..
4 Answers
...
Toggle input disabled attribute using jQuery
...lse).
So in this case, I used a function that supplied me the index (i) and the current value (v), then I returned the opposite of the current value, so the property state is reversed.
share
|
im...
What is a stack trace, and how can I use it to debug my application errors?
...ject.Book.getTitle(Book.java:16)
To debug this, we can open up Book.java and look at line 16, which is:
15 public String getTitle() {
16 System.out.println(title.toString());
17 return title;
18 }
This would indicate that something (probably title) is null in the above code.
Exam...
Remove an onclick listener
I have an object where the text cycles and displays status messages. When the messages change, I want the click event of the object to change to take you to the activity that the message is relating to.
...
How can I send an email by Java application using GMail, Yahoo, or Hotmail?
...
First download the JavaMail API and make sure the relevant jar files are in your classpath.
Here's a full working example using GMail.
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class Main {
private static String U...
How to get Url Hash (#) from server side
... Javascript:
When the form submits, grab the hash (window.location.hash) and store it in a server-side hidden input field Put this in a DIV with an id of "urlhash" so we can find it easily later.
On the server you can use this value if you need to do something with it. You can even change it if yo...