Hint of the day #2 : Creating a Map or Seq. with Freemarker

[zomurn]

This example enumerate all the associations of the root node "person".
Each association value is a nodeRef to a node of type cmerson
Hence, this freemarker script list the usernames associated with the current person : allow to represent a human hierarchy inside a company.

In two steps :

1) Create the Map "as string"
2) Cast the string to a Map object with the instruction :

<#assign map = mapAsString?eval/>‍

3) Test for NON existence of a key in the map :

<#if !map["keynotexist"]??>‍

<#assign mapAsString = "{"/>
<#assign first = true />
<#list person.assocs["cm:subscribedBy"] as subscriber>
    <#if first = false>
        <#assign mapAsString = mapAsString + ","/>
    </#if>
    <#assign mapAsString = mapAsString + "\"" + subscriber.properties["userName"] + "\":" + "\"" + subscriber.properties["userName"] + "\""/>
    <#assign first = false/>
</#list>
<#assign mapAsString = mapAsString + "}"/>
 
<#assign map = mapAsString?eval/>
<p><i>map size: ${map?size}</i></p>
<#assign keys = map?keys>
<#list keys as key>
   ${key} = ${map[key]}
</#list> 
<#if !map["keynotexist"]??>
   <p><i>key not found</i></p>
<#else>
   <p><i>key found</i></p>
</#if>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

If you want a sequence, just build the String. For example "[value1,value2,…]" and then call "eval" like above.
And then do traverse like in the freemarker doc reference :  http://www.freemarker.org/docs/ref_builtins_hash.html

PS : according to the freemarker doc reference order may be maintained in the map. So I'am quite suspicious that behind this is a real java map…So it means that Map and Sequence in Freemarker looks to be the same java underlying data structure : a List, because they maintained the order both.

Hoping it might help someone (this hints in missing in the wiki)

[mrogers]

Please go ahead add your examples and hints to the wiki if you realise something is missing.

[lyamamot]

PS : according to the freemarker doc reference order may be maintained in the map. So I'am quite suspicious that behind this is a real java map…So it means that Map and Sequence in Freemarker looks to be the same java underlying data structure : a List, because they maintained the order both.

Thanks for the cool tip on how to form a map from a string!

I just wanted to point out that in Java, a LinkedHashMap maintains insertion order of the keys so the underlying structures may be different.

[zomurn]

As I've just seen, you might be right. That's true.

mrogers > I will put this hint on the wiki later so. But everyone can post on it ?

[mrogers]

Yes, all community members can update the wiki and I'd encourage everyone to do so as and when they see something missing or not quite right.