Grails GSP Loop through an index and do somthing with selected lines - loops

Question

In an Index-gsp, I want to be able to select an arbitrary number of lines and then by clicking a link send all those lines to a controller for processing e.g. creating new objects of a different kind.
I've no idea how selection can be done or how to collect these selected lines in a GSP. Maybe I should use a checkbox on each line if that's possible?
It's a list of products which is displayed using a modified index.gsp.
Each product-line has a checkbox in front.
What I want is to make a list of the products that are checked an then transmit this list to a controller.
a part of this index.gsp:
<li><a class="home" href="${createLink(uri: '/')}"><g:message code="default.home.label"/></a></li>
<li><g:link class="create" action="create"><g:message code="default.new.label" args="[entityName]" /></g:link></li>
<li><g:link class="create" action="createOffer"><g:message code="default.new.label" args="[entityName]" params="toOffer" /></g:link></li>
</ul>
</div>
<div id="list-prodBuffer" class="content scaffold-list" role="main">
<h1><g:message code="default.list.label" args="[entityName]" /></h1>
<g:if test="${flash.message}">
<div class="message" role="status">${flash.message}</div>
</g:if>
<table>
<thead>
<tr>
<td> Välj</td>
<td> ID</td>
</tr>
</thead>
<tbody>
<g:each in="${prodBufferList}" status="i" var="prodBuffer">
<tr class="${ (i % 2) == 0 ? 'even': 'odd'}">
<td><g:checkBox name="toOffer" value="${prodBuffer.id}" checked="false" /></td>
<td>${prodBuffer.id}</td>
So this not an ordinary form, just a list where I want to use a link to transmit it to the controller.
I'm a beginner and have no idea how to do it.

Answer 1

You can collect all necessary data from page using javascript, and then send all data to your controller for processing.
There are a lot of ways to do it.
For example send via JQuery:
<script>
//some code
var items = [1,2,3];
//some code
$('#add-location').click(function () {
$.ajax({
type: "POST",
url: "${g.createLink(controller:'myController', action: 'myControllerMethod')}",
data: {items: items},
success: function (data) {
console.log(data)
}
});
});
</script>

Answer 2

I will answer this but have to slow down since it feels like i am beginning to write your project:
In gsp you will need to have a hidden field followed by a check box amongst data you are trying to capture, checkbox should contain all the data elements required to build your output.
<g:hiddenField name="userSelection" value=""/>
<g:checkBox name="myCheckBox" id='myCheckBox' value="${instance.id}"
data-field1="${instance.field1}" data-field1="${instance.field1}"
checked="${instance.userSelected?.contains(instance.id)?true:false}" />
In the java script segment of the page you will need to add the following
This will then auto select selection and add to javascript array
// Customized collection of elements used by both selection and search form
$.fn.serializeObject = function() {
if ($("[name='myCheckBox']:checked").size()>0) {
var data=[]
$("[name='myCheckBox']:checked").each(function() {
var field1=$(this).data('field1');
var field2=$(this).data('field2');
data.push({id: this.value, field1:field1, field2:field2 });
});
return data
}
};
Most importantly will your data sit across many different gsp listing pages if so you will need to hack pagination:
//Modify pagination now to capture
$(".pagination a").click(function() {
var currentUrl=$(this).attr('href');
var parsedUrl=$(this).attr('href', currentUrl.replace(/\&userSelection=.*&/, '&').replace(/\&userSelection=\&/, '&'));
var newUrl=parsedUrl.attr('href') + '&userSelection=' + encodeURIComponent($('#userSelection').val());
window.location.href=newUrl
return false;
});
Then in the controller parse the JSON form field and make it into what you want when posted
def u=[]
def m=[:]
if (params.userSelection) {
def item=JSON.parse(params.userSelection)
item?.each {JSONObject i->
// When field1 is null in JSON set it as null properly
if (JSONObject.NULL.equals(i.field1)) {
i.field1=null
}
if (resultsGroup) {
if (!resultsGroup.contains(i.id as Long)) {
u << i
}
} else {
u << i
}
}
m.userSelected=item?.collect{it.id as Long}
m.results=u
}
return m