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Toolkit - JSON Models

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This post if part of a series about the File System Toolkit - a custom content delivery API for SDL Tridion.

This post explains the format of JSON model files, which look typically like this:

{
  "cp" : [ {
    "c" : 10,
    "cnt" : "Rendered CP content",
    "pr" : 300,
    "p" : 6,
    "t" : 15
  }, {
    "c" : 10,
    "cnt" : "Rendered CP content",
    "pr" : 200,
    "p" : 6,
    "t" : 25
  } ],
  "cstm" : {
    "meta" : {
      "Float" : {
        "k" : "Price",
        "n" : [ 2.0 ],
        "t" : "NUMERIC"
      },
      "Date" : {
        "k" : "ArticleDate",
        "d" : [ 72602000 ],
        "t" : "DATE"
      },
      "String" : {
        "k" : "Authors",
        "s" : [ "Lolek", "Bolek" ],
        "t" : "STRING"
      }
    }
  },
  "m" : 1450673231000,
  "p" : 1482016384618,
  "lnk" : [ {
    "c" : 10,
    "pg" : 20,
    "pr" : 300,
    "p" : 6,
    "u" : "/page1.html"
  }, {
    "c" : 10,
    "pg" : 30,
    "pr" : 300,
    "p" : 6,
    "u" : "/page2.html"
  } ],
  "sch" : 46,
  "tcm" : {
    "p" : 6,
    "i" : 10,
    "t" : 16
  },
  "t" : "News Article Sample",
  "mm" : false
}

The JSON above is saved in file 6-10.json, where 6 stands for the Publication id and 10 is the Component item id.

The model contains several parts: Component Presentations (cp), CustomMeta (cstm) and Links (lnk). Also it contains the last modified date (date when it was last saved in Tridion) - (m), last published date (p), Schema Id (sch), TcmUri (tcm), Title (t), Multimedia (mm).

The Component Presentation section contains all Dynamic Component Presentations on this Component and specifies their Component id (c), content (cnt), linking priority (pr), Publication Id (p) and Component Template Id (t).

The CustomMeta section contains all custom meta field and defines it as an array of metadata items (meta). Each item defining a key (k), a value and a type (t). The value can be one of three possible values: numeric (n), date (d), or string (s).

The Link section contains information about all links to this Component, such as Component Id (c), Page item Id (pg), link priority (pr), Publication Id (p), and page URL (u).

The TcmUri is represented as an object having a Publication Id (p), and Item Id (i) and a Type Id (t).

The static Component Presentations of a Component appear on the Page model that contains them. For example on the Page model below, there is one static Component Presentation specified by its Component Id (c), Linking priority (pr), Publication Id (p) and Component Template item Id (t).

{
  "cp" : [ {
    "c" : 10,
    "pr" : 200,
    "p" : 6,
    "t" : 15
  } ],
  "f" : "/page3.html",
  "m" : 1447029194000,
  "p" : 1482016423976,
  "pt" : 54,
  "tcm" : {
    "p" : 6,
    "i" : 12,
    "t" : 64
  },
  "t" : "Sample Page 3",
  "u" : "/page3.html"
}

JSON models are placed in a folder structure under the jsonRoot folder specified in the toolkit.properties file.

The location of a JSON model file on the file system, under the jsonRoot folder is given by a path derived from the TCM URI of the item. The hash-code of the TcmUri is calculated, using Java's String.hashCode() method. Then we retain the last 4 digits of this hash-code. This gives us the 4-level deep path for the specified model.

Example:
We want to calculate the path for model with TCM URI: tcm:6-1225-64
1. First we calculate the string hash-code: 866716204
2. We retain the last 4 digits: 6204
3. We calculate the path: 6/2/0/4/
4. We append the TCM URI without prefix "tcm:", which gives: 6/2/0/4/6-1225-64.json
5. We prepend the jsonRoot folder: /my/jsonRoot/6/2/0/4/6-1225-64.json



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