FreeMarker FTL json

json.ftl

#-- 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",
	"getclass",
	"getmethod",
	"getenclosingmethod",
	"getcanonicalname",
	"hashcode",
	"getproviders",
	"getdeclaredfields",
	"cast",
	"equals",
	"tostring",
	"isdisplayinfo",
	"islocalclass",
	"isinstance",
	"isinterface",
	"issynthetic",
	"assubclass",
	"getfield",
	"getcomponenttype",
	"isarray",
	"isprimitive",
	"isannotation",
	"getdeclaredconstructors",
	"isassignableform",
	"isassignablefrom",
	"getdeclaringclass",
	"package"
] />

<#--
  -- The main macro.
  -->

<#macro stringify data depth=0>
<#compress>
<#if depth gt 6>
	/* stringify: refusing to run ${depth} */
	<#return>
</#if>
	<#--
  	  -- Test for hashes/objects
  	-->
	<#local isHash = false>
	<#attempt>
		<#local isHash = data?is_hash || data?is_hash_ex>
		<#recover>
			/* can't evaluate if object is hash */
			undefined
		<#return>
	</#attempt>

	<#if isHash>
		<#attempt>
			<@printHashEx data depth+1 />,
		<#recover>
			undefined
			/* printHashEx failed */
			<#return>
		</#attempt>
	</#if>

	<#--
	  -- Test for arrays
	-->
	<#local isEnumerable = false>
	<#attempt>
		<#local isEnumerable = data?is_enumerable>
		<#--/* stringify: data is enumerable? ${isEnumerable?c} */-->
		<#recover>
			undefined
			/* can't evaluate if object is enumerable */
		<#return>
	</#attempt>

	<#if isEnumerable>
		<#attempt>
			<@printList data />,
		<#recover>
			undefined
			/* printList failed */
			<#return>
		</#attempt>
	</#if>

	<#local isMethod = false>
	<#attempt>
		<#local isMethod = data?is_method>
		<#--/* stringify: data is a method? ${isMethod?c} */-->
		<#recover>
			/* can't test if object is a method */
			undefined
		<#return>
	</#attempt>

	<#if isMethod>
		undefined
	</#if>

	<#local isBoolean = false>
	<#attempt>
		<#local isBoolean = data?is_boolean>
		<#--/* stringify: data is a boolean? ${isBoolean?c} */-->
	<#recover>
		/* can't test if object is a boolean */
		undefined
		<#return>
	</#attempt>

	<#if isBoolean>
		${data?c}
	</#if>

	<#local isString = false>
	<#attempt>
		<#local isString = data?is_string>
		<#--/* stringify: data is a boolean? ${isBoolean?c} */-->
	<#recover>
		/* can't test if object is a boolean */
		<#return>
	</#attempt>

	<#if isString>
		<#if data?lower_case?index_of("bean") gte 0>
            <#return>
        </#if>
		<#t>"${data?json_string}"
	</#if>
</#compress>
</#macro>

<#macro debug data>
	<#attempt>
		/* debug: hasContent? ${data?has_content?c} */
		/* debug: hasApi? ${data?has_api?c} */
		/* debug: isHash? ${data?is_hash?c} */
		/* debug: isEnumerable? ${data?is_enumerable?c} */
		/* debug: isString? ${data?is_string?c} */
		/* debug: isBoolean? ${data?is_boolean?c} */
		/* debug: isMethod? ${data?is_method?c} */
		/* debug: isSequence? ${data?is_sequence?c} */
		/* debug: isCollection? ${data?is_collection?c} */
		/* debug: isCollectionEx? ${data?is_collection_ex?c} */
	<#recover>
		/* can't debug */
		<#return>
	</#attempt>

</#macro>

<#macro rawStringify data>
  /* called rawStringify /*
  <#if data?is_enumerable>
    <@printList data />
  <#elseif data?is_hash>
    <@printHashEx data />
  </#if>
</#macro>

<#macro printList data>
	/* printList start */
	<#list data>
		[${'\n'}
		<#items as item>
			<#attempt>
				<@printListItem item />
			<#recover>
					/* printList: couldn't call printListItem */
				<#return>
			</#attempt>
			<#--"${item}"-->
			<#sep>,</#sep>
			<#--/* isString: "${item?is_string?c}" */-->
			<#--/* isMethod: "${item?is_boolean?c}" */-->
			<#--/* isBoolean: "${item?is_boolean?c}" */-->
		</#items>
		]${'\n'}
	<#else>
		/* printList empty! */
		[]
	</#list>
	/* printList end */
</#macro>

<#macro printHashEx hash depth=0>
	${'\t'}
	<#if depth gt 7>
		/* printHashEx: refusing to run ${depth} */
		<#return>
	</#if>
	<#t>{
		<#list hash as key, item>
			<#if omit(key?string)>
				<#continue>
			</#if>
			"${key}":<@stringify item!'' depth+1 /><#sep>,</#sep>
			<#--"${key}":<#if item??><@printHashItem item key depth /></#if>-->

		</#list>}
</#macro>


<#macro printHashItem item key depth>
	<#if depth gt 7>
		/* printHashItem: refusing to run ${depth} */
		undefined
		<#return>
	</#if>

	/* call printHashItem with ${key} */
	<#if omit(key?string)>
		/* omit: ${omit(key?string)?c} */
		undefined
		<#return>
	</#if>

	<#if item?is_enumerable>
		/* printHashItem -> printList */
		<#t>"${key?js_string}":<@printList item />
	<#elseif item?is_hash_ex && omit(key?string)><#-- omit bean-wrapped java.lang.Class objects -->
		undefined
	<#elseif item?is_hash>
		/* printHashItem -> printHashEx */
		"${key?js_string}":<@printHashEx item depth+1 />
	<#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?c}
	<#elseif item?is_date>
		<#t>"${key?js_string}":"${item?string("yyyy-MM-dd'T'HH:mm:sszzzz")}"
	</#if>
</#macro>

<#macro printListItem item>
	/* printListItem */
	<#if item?is_enumerable>
		/* printListItem -> printList */
		<#t><@printList item />
	<#elseif item?is_hash_ex>
		/* printListItem -> printHashEx */
		<@printHashEx item />
	<#elseif item?is_number>
		<#t>${item?string.computer}
	<#elseif item?is_string>
		<#t>"${item?js_string}"
	<#elseif item?is_boolean>
		<#t>"${item?c}"
	<#elseif item?is_date>
		<#t>"${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>