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Posted to commits@struts.apache.org by lu...@apache.org on 2017/04/02 09:13:05 UTC
[04/13] struts-site git commit: cleaned up the form-validation page
cleaned up the form-validation page
Project: http://git-wip-us.apache.org/repos/asf/struts-site/repo
Commit: http://git-wip-us.apache.org/repos/asf/struts-site/commit/d7ba877e
Tree: http://git-wip-us.apache.org/repos/asf/struts-site/tree/d7ba877e
Diff: http://git-wip-us.apache.org/repos/asf/struts-site/diff/d7ba877e
Branch: refs/heads/master
Commit: d7ba877e4db101d60f2f0e4604d7fa958e204e0e
Parents: f2cb6c6
Author: Stefaan Dutry <st...@gmail.com>
Authored: Sat Apr 1 20:24:29 2017 +0200
Committer: Stefaan Dutry <st...@gmail.com>
Committed: Sat Apr 1 20:24:29 2017 +0200
----------------------------------------------------------------------
source/getting-started/form-validation.md | 82 ++++++++------------------
1 file changed, 26 insertions(+), 56 deletions(-)
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http://git-wip-us.apache.org/repos/asf/struts-site/blob/d7ba877e/source/getting-started/form-validation.md
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diff --git a/source/getting-started/form-validation.md b/source/getting-started/form-validation.md
index 0d16c4c..bf4a3b4 100644
--- a/source/getting-started/form-validation.md
+++ b/source/getting-started/form-validation.md
@@ -4,7 +4,7 @@ title: Form Validation
---
## Form Validation
-This tutorial assumes you've completed the _Processing Forms_ tutorial and have a working form_processing project. The example code for this tutorial, form_validation, is available for checkout from the Struts 2 GitHub repository: [https://github.com/apache/struts-examples](https://github.com/apache/struts-examples).
+This tutorial assumes you've completed the [Processing Forms](processing-forms.html) tutorial and have a working form_processing project. The example code for this tutorial, form_validation, is available for checkout from the Struts 2 GitHub repository: [https://github.com/apache/struts-examples](https://github.com/apache/struts-examples).
>
@@ -12,21 +12,17 @@ __Introduction__
In this tutorial we'll explore using Struts 2 to validate the user's input on a form. There are two ways you can use Struts 2 to do form validation. This tutorial will cover the more basic method, where the validation is included in the Struts 2 Action class.
-
-
-| The [Struts 2 user mailing list](http://struts.apache.org/mail.html)^[http://struts.apache.org/mail.html] is an excellent place to get help. If you are having a problem getting the tutorial example applications to work search the Struts 2 mailing list. If you don't find an answer to your problem, post a question on the mailing list.
-
-|
+The [Struts 2 user mailing list](http://struts.apache.org/mail.html) is an excellent place to get help. If you are having a problem getting the tutorial example applications to work search the Struts 2 mailing list. If you don't find an answer to your problem, post a question on the mailing list.
__Add validate Method__
To enable the Struts 2 Action class to validate a user's input on a Struts 2 form, you must define a validate method in your Action class. Using the example from _Processing Forms_ tutorial, let's say that we have these business rules:
1. User must provide a first name
- 2. User must provide an email address
- 3. User younger then 18 cannot register
+2. User must provide an email address
+3. User younger then 18 cannot register
-If you recall from the _Processing Forms_ tutorial the user's input into the form fields is placed by Struts 2 into the Java model class personBean. So a user's input into the firstName field would end up as the value for personBean's firstName instance field (via the personBean.setFirstName method).
+If you recall from the [Processing Forms](processing-forms.html) tutorial the user's input into the form fields is placed by Struts 2 into the Java model class personBean. So a user's input into the firstName field would end up as the value for personBean's firstName instance field (via the personBean.setFirstName method).
In the validate method we can refer to get the values of personBean's instance fields by using the appropriate get methods. Once we have the values we can employ logic to enforce our business rules.
@@ -34,33 +30,21 @@ Add the following validate method to Register.java (the Action class).
**validate method**
+```java
+ public void validate(){
+ if (personBean.getFirstName().length() == 0) {
+ addFieldError("personBean.firstName", "First name is required.");
+ }
-~~~~~~~
- public void validate(){
-
- if ( personBean.getFirstName().length() == 0 ){
-
- addFieldError( "personBean.firstName", "First name is required." );
-
- }
-
-
- if ( personBean.getEmail().length() == 0 ){
-
- addFieldError( "personBean.email", "Email is required." );
-
- }
-
- if ( personBean.getAge() < 18 ){
-
- addFieldError( "personBean.age", "Age is required and must be 18 or older" );
-
- }
-
-
- }
+ if (personBean.getEmail().length() == 0) {
+ addFieldError("personBean.email", "Email is required.");
+ }
-~~~~~~~
+ if (personBean.getAge() < 18) {
+ addFieldError("personBean.age", "Age is required and must be 18 or older");
+ }
+ }
+```
When the user presses the submit button on the register form, Struts 2 will transfer the user's input to the personBean's instance fields. Then Struts 2 will automatically execute the validate method. If any of the if statements are true, Struts 2 will call its addFieldError method (which our Action class inherited by extending ActionSupport).
@@ -72,11 +56,9 @@ So what should we do if Struts 2 returns "input" indicating that the user's inpu
To handle the return value of "input" we need to add the following result to our action node in struts.xml.
-
-~~~~~~~
+```xml
<result name="input">/register.jsp</result>
-
-~~~~~~~
+```
The above result node goes just after the success result node for the register action and before the closing of the action node.
@@ -86,15 +68,13 @@ So when validation fails and Struts 2 returns input, the Struts 2 framework will
So the following addFieldError method call:
-
-~~~~~~~
-addFieldError( "personBean.firstName", "First name is required.")
-
-~~~~~~~
+```java
+ addFieldError("personBean.firstName", "First name is required.")
+```
will cause the message "First name is required" to be displayed above the firstName field on the form.
-If you have made the above changes to the _Processing Forms_ tutorial or you have downloaded from [Google Code](http://code.google.com/p/struts2-examples/downloads/list)^[http://code.google.com/p/struts2-examples/downloads/list] either the Form_Validation_Struts2_Ant or Form_Validation_Struts2_Mvn projects run the application (see the README.txt in the project root folder). Click on the Please register link. On the registration form, just click the submit button and you should see:
+If you have made the above changes to the _Processing Forms_ tutorial or you have downloaded from [Google Code](http://code.google.com/p/struts2-examples/downloads/list) either the Form_Validation_Struts2_Ant or Form_Validation_Struts2_Mvn projects run the application (see the README.txt in the project root folder). Click on the Please register link. On the registration form, just click the submit button and you should see:
@@ -102,23 +82,13 @@ Struts 2 called the validate method, validation failed, the register.jsp was dis
__Styling The Error Messages__
-The Struts 2 s:head tag can be used to provide CSS that includes a style for the error message. Add
-
-~~~~~~~
-<s:head />
-~~~~~~~
- to register.jsp before the closing HTML
-
-~~~~~~~
-</head>
-~~~~~~~
- tag. Go through the same steps as above and you should see:
+The Struts 2 s:head tag can be used to provide CSS that includes a style for the error message. Add `<s:head />` to register.jsp before the closing HTML `</head>` tag. Go through the same steps as above and you should see:
__Summary__
-This tutorial covered validating a user's form input by adding a validate method to an Action class. There is another more sophisticated way to validate user input using XML. If you want to learn more about using XML for validation in Struts 2 see _Validation_ .
+This tutorial covered validating a user's form input by adding a validate method to an Action class. There is another more sophisticated way to validate user input using XML. If you want to learn more about using XML for validation in Struts 2 see [Validation](//struts.apache.org/docs/validation.html) .
__Up Next__