在ag中使用get进行Grails：每个

Question

I'll acknowledge right off that the title is probably not the right reference here so please let me know if I'm using the wrong phrase and I'll correct!

Overview - I have an Form.gsp and corresponding _form.gsp, into which I feed a load of values from an SQL query, which includes the ID from another controller (called Object, multiple object being linked to a form).

During the construction of the table which lists all these objects I need to take the object id and then get it to go off to the Object controller, use the ID to return the objects name and populate the text box with that value. But I can't work out how to do this, here's what I've tried (cutting out the rubbish of course).

The Objects ID is called object_id and the g:each var is item. So I've tried to insert it my Object.get(x) as: -

value = "${Object.get(item.object_id)}"

But this give the error No signature of method: static java.lang.Object.get() is applicable for argument types: (java.math.BigDecimal) values: [4]

Incidentally the ID value is 4 that I need to look for...

I've also tried

value = "${Object.get(${item.object_id})}"

But I get an Unclosed GSP expression error.

This is within my _form.gsp

<table id="eventList">
        <g:each in="${results}" status = "i" var="item">
            <tr>
                <td colspan="3">
                    <table id = "sub">
                        <tr>
                            <td><b>Object</b></td><td>
                            <g:select style="width:550px;"id="objectID[$i]" name="objectID[$i].id" from="${framework.Object.list(sort:"objDesc")}" optionKey="id" required="" value="${item.object_id}" class="many-to-one"/>

                            <richui:autoComplete name="objectID[$i].id" value = "${Object.get(item.object_id)}" action="${createLinkTo('dir': 'object/searchAJAX')}"    />

                            </td>

                        </tr>
                    </table>                                
                </td>       
            </tr>
        </g:each>
    </table>

Also worth noting that I do just want it to return and display the objDesc value not the whole entry and am not sure how I tell it to basically say "give me back the objDesc where the ID = item.object_ID.

Thanks for any help!

Answer 1

I have come up with a workaround for this, as I'm using SQL in my controller to send the info to the gsp I simple added in another JOIN to the statement to go and get the objects description value from the object table before I passed through the details, I can now reference it with an "item.object_description"

However, I'd still like to know if its possible to do the look-up as originally intended so I wont mark this as answered just yet...

Answer 2

The first error you're getting:

No signature of method: static java.lang.Object.get() is applicable for argument types: (java.math.BigDecimal) values: [4]

Indicates that the Object.get() call in your <richui> tag isn't actually accessing your domain object; it's just the generic java.lang.Object class.

There's a couple of ways you might work around this.

First, you could just import the domain class into your main Form.gsp, and then _form.gsp should inherit it when you it:

<%@ page import="com.mysite.DomainObject" %>

Make sure to change the "com.mysite." portion to match the package name of your domain object. The default package in a grails application is the same as the name of your application. So, your import might look like <%@ page import="myApp.Object" %>

Second (more elaborate) way: in your controller, you could pass the actual domain objects you want to access to the gsp. So, at the end of your controller action, you might have something like:

def sqlResults = someService.queryMethod(parameter1, parameter2)
def domainObjects = DomainObject.findAllBy( it.property == parameter3 )
[results: sqlResults, myObjects: domainObjects]

Given the way you're iterating through the results object using g:each, you may actually need to map the domain objects to the members of your sqlResults. This method is certainly more elaborate than just importing the domain object to your gsp, though it bears considering. Why run sql statements to get the IDs of your domain object when you can use the Grails frameworks findAll methods?

Side note: If you're actually naming your domain class Object, you might consider refactoring with a more domain-specific name, just to avoid any ambiguity. I imagine you just did that for your post, so that it would be more generic, which is fine, but consider using a class name that isn't already in use at the lowest levels of the language.