[jbossseam-issues] [JBoss JIRA] Commented: (JBSEAM-2133) inline EL in component property value not properly detected
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https://jira.jboss.org/jira/browse/JBSEAM-2133?page=com.atlassian.jira.pl...
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Dan Allen commented on JBSEAM-2133:
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I believe that I have a perfect solution for this problem. If the entire value is a single
EL value expression, then we evaluate it when setting the bean property. We will call this
a component reference (since that is the only way to refer to a component in the Seam
component descriptor). If the value has mixed content, then it will not be evaluated
before assigning to the property. This gives the developer the choice to evaluate it
during the @Create method or at a later time. This is mostly how it works today, except
that if the value starts with #{ we evaluate it, even if the content is mixed, so that is
where the inconsistent behavior comes in.
In an ideal world, we would always interpolate the value unless the target property's
type is ValueExpression. However, if we make that change I fear we will break a lot of
people's applications. We will also need to change the restrictions property on the
Query component to be an array of ValueExpression objects instead of strings.
inline EL in component property value not properly detected
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Key: JBSEAM-2133
URL: https://jira.jboss.org/jira/browse/JBSEAM-2133
Project: Seam
Issue Type: Bug
Components: Core
Affects Versions: 2.0.0.CR2
Reporter: Dan Allen
Assignee: Dan Allen
Fix For: 2.1.0.CR1
Attachments: JBSEAM-2133-v1.txt
Currently, the EL notation in a property is only being evaluated if the property starts
with "#{". There are two problems with this assumption.
1. Inline EL can only be used if the property starts with an expression (i.e.
<property name="message">#{applicationName} is a cool
application</property>)
2. There is no way to escape EL so that is is evaluated by the property accepting the
string (rather than when the value is assigned).
The correct behavior would be to treat the property value as a value expression if it
CONTAINS "#{". The benefits are two fold:
1. A property value can use inline EL that is evaluated when the property value is set
(see above)
2. The resolved value of the property can be EL (delayed EL) that is to be interpreted by
the component as needed. This is done by escaping the EL per the unified EL spec (i.e.
<property name="created-message">The user \#{user.name} has been
created!</property)
Surprisingly, everything is already in place. All that needs to happen is the check for
EL needs to change from "startsWith" to "contains".
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