How to pass parameters in <a href tag in grails gsp

Question

This is the code I am using in the gsp file to fetch the data to show on the view page:

   <datePicker id="startDate" name="startDate" value="${new  
 Date().minus(2).format('yyyy-MM-dd')}"  />

the datepicker I am using in the same page.

Now i need to pass the datepicker parameters to this link

   <a id="exportIcon" href="${createLink(controller: entityName, action:  
 'mrInventoryExcelExport', params: [StartDate:startDate])}" >

the parameter is the startdate which i enter manually in the form
Can anyone tell me how can i achieve this.

Answer 1

You could just use a button & submit the form to the given action then either deal with it in the action directly:

gsp:

<g:actionSubmit name="exportIcon"       
                action="mrInventoryExcelExport" 
                value="Export"/>

controller:

def mrInventoryExcelExport() {
    def startDate = params.startDate
    ...
}

Or redirect to another action with the startDate:

gsp:

<g:actionSubmit name="exportIcon"       
                action="anotherAction" 
                value="Export"/>

controller:

def anotherAction() {
    redirect( controller: 'entityName', action: 'mrInventoryExcelExport', params:[startDate: params.startDate] )
}

Answer 2

You need to understand the mechanics. GSP is a server-side technology. Whatever related you have in there, will be processed and converted to HTML, before it is sent to the client/browser.

Now, what you're asking to include/change a parameter in the link, based on the value picked by user; mind you, the link is already created. No chance? Using JavaScript to create that link is your best bet.

PS: Try to see the page source from the browser, for more insight.