Macros with readers, how does it work?

The easiest way to read a file is store it in context's repository and access it with */file. The * will expand into rendering context repository. For example:

{@marker-xml:xml:doc:*/doc.xml}

Reads doc.xml in current repository and passes its data to [Template_root]/xml/docTemplate.html to be formatted.

Reading properties

Properties are stored in props list in the same order they are stored on disc. You can iterate props with #list.

<#list props?keys as key>
   <#assign value=props[key]/>
   // do something with key and value
   ...
< /#list>

Reading XML

XML documents are stored in doc model. You can iterate the elements using dot syntax and iterate collections as you would usually do for any other data. The XML model is the FreeMarker NodeModel.

Reading JSON

JSON files are stored in json model. To access a root, use json.read("$.root"). If the root is a list, use json.list("$.root"). Once retrieved the root, you can iterate the elements using dot syntax and iterate collections as you would usually do for any other data. The JSON model is a subset of the JsonPath DocumentContext, optimized for templates usage.

The JSON books example

The data:

{
  "book": [
    {
      "title": "...",
      "author": "...",
      "excerpt": "...",
      "availability": "...",
      "link": "...",
      "filelink": "...",
      "imagelink": "...",
      "pages": 0
    },
    {
      ...
    },
    ...
  ]
}

The template (Semantic-UI):

<div class="ui divided items">
  <#list json.list("$.book") as book>
    <div class="item">
      <a class="ui tiny image" href="${book.link}">
        <img src="${book.imagelink}"/>
      </a>
      <div class="content">
        <a class="header" href="${book.link}">${book.title}</a>
        <div class="meta">
          ${book.author}
        </div>
        <div class="description">
          ${book.excerpt}
        </div>
        <div class="extra">
          ${book.availability}
          <#if book.filelink?has_content>
            <a target="_new" href="${book.filelink}">${book.pages}</a>
          < /#if>
        </div>
      </div>
    </div>
  < /#list>
</div>