json.ftl

<#-- json.ftl
  --
  -- Generates JSON of data model items.
  --
  -- Usage:
  -- <#import "json.ftl" as json>
  --
  -- <@json.stringify your_model_here />
  --
  -->


<#-- The black_list contains bad hash keys. Any hash key which matches a 
  -- black_list entry is prevented from being displayed.
  -->
<#assign black_list = ["class"] />


<#-- 
  -- The main macro.
  -->
  
<#macro stringify data escape="none"><@compress single_line=true>
  <#assign generated_json><@rawStringify data /></#assign>
  <#if escape == "html">
    ${generated_json?html}
  <#elseif escape == "js_string">
    ${generated_json?js_string}
  <#else>
    ${generated_json}
  </#if>
</@compress></#macro>

<#-- private helper macros. it's not recommended to use these macros from 
  -- outside the macro library.
  -->

<#macro rawStringify data>
  <#if data?is_enumerable>
    <@printList data,[] />
  <#elseif data?is_hash_ex>
    <@printHashEx data,[] />
  </#if>
</#macro>

<#macro printList list has_next_array>
  <#local counter=0 />
  <#local highestIndex = list?size-1 />
  <#t>[<#list list as item><@printListItem item?if_exists,has_next_array+[item_has_next], counter /><#if counter < highestIndex>,</#if><#local counter = counter + 1/></#list>]
</#macro>

<#macro printHashEx hash has_next_array>
  <#local isFirst=true />
  <#t>{<#list hash?keys as key><#if !isFirst>,</#if><@printItem hash[key]?if_exists,has_next_array+[key_has_next], key /><#local isFirst = false /></#list>}
</#macro>

<#macro printItem item has_next_array key>
<#if item?is_enumerable>
<#t>"${key?js_string}":<@printList item, has_next_array />
<#elseif item?is_hash_ex && omit(key?string)><#-- omit bean-wrapped java.lang.Class objects -->
<#elseif item?is_hash_ex>
<#t>"${key?js_string}":<@printHashEx item, has_next_array />
<#elseif item?is_number>
<#t>"${key?js_string}":${item?string.computer}
<#elseif item?is_string>
<#t>"${key?js_string}":"${item?js_string}"
<#elseif item?is_boolean>
<#t>"${key?js_string}":${item?string}
<#elseif item?is_date>
<#t>"${key?js_string}":"${item?string("yyyy-MM-dd'T'HH:mm:sszzzz")}"
</#if>
</#macro>

<#macro printListItem item has_next_array key>
<#if item?is_enumerable>
<#t><@printList item, has_next_array />
<#elseif item?is_hash_ex && omit(key?string)><#-- omit bean-wrapped java.lang.Class objects -->
<#elseif item?is_hash_ex>
<#t><@printHashEx item, has_next_array />
<#elseif item?is_number>
<#t>${item?string.computer}
<#elseif item?is_string>
<#t>"${item?js_string}"
<#elseif item?is_boolean>
<#t>${item?string}
<#elseif item?is_date>
<#t>"${item?string("yyyy-MM-dd'T'HH:mm:sszzzz")}"
</#if>
</#macro>

<#function omit key>
    <#local what = key?lower_case>
    <#list black_list as item>
        <#if what?index_of(item) gte 0>
            <#return true>
        </#if>
    </#list>
    <#return false>
</#function>