Flowed ST

JSON Selector + Transformer

Based on ST: https://selecttransform.github.io/site

See differences compared to the original

---

1. Select: Query any JSON tree to select exactly the subtree you are looking for.
2. Transform: Transform any JSON object to another by parsing with a template, also written in JSON

You can also mix and match Select AND Transform to perform partial transform, modularize JSON objects, etc.

Features

1. Select

Select a JSON object or its subtree that matches your criteria

Step 1. Take any JSON object

var data = {
  "links": [
    { "remote_url": "http://localhost" },
    { "file_url": "file://documents" },
    { "remote_url": "https://blahblah.com" }
  ],
  "preview": "https://image",
  "metadata": "This is a link collection"
}

Step 2. Find all key/value pairs that match a selector function

var sel = ST.select(data, function(key, val) {
  return /https?:/.test(val);
})

Step 3. Get the result

var keys = sel.keys();
//  [
//    "remote_url",
//    "remote_url",
//    "preview"
//  ]

var values = sel.values();
//  [
//    "http://localhost",
//    "https://blahblah.com",
//    "https://image"
//  ]

var paths = sel.paths();
//  [
//    "[\"links\"]",
//    "[\"links\"]",
//    ""
//  ]

2. Transform

Use template to transform one object to another

Step 1. Take any JSON object

var data = {
  "title": "List of websites",
  "description": "This is a list of popular websites"
  "data": {
    "sites": [{
      "name": "Google",
      "url": "https://google.com"
    }, {
      "name": "Facebook",
      "url": "https://facebook.com"
    }, {
      "name": "Twitter",
      "url": "https://twitter.com"
    }, {
      "name": "Github",
      "url": "https://github.com"
    }]
  }
}

Step 2. Select and transform with a template JSON object

var sel = ST.select(data, function(key, val){
            return key === 'sites';
          })
          .transformWith({
            "items": {
              "{{#each sites}}": {
                "tag": "<a href='{{url}}'>{{name}}</a>"
              }
            }
          })

Step 3. Get the result

var keys = sel.keys();
//  [
//    "tag",
//    "tag",
//    "tag",
//    "tag"
//  ]

var values = sel.values();
//  [
//    "<a href='https://google.com'>Google</a>",
//    "<a href='https://facebook.com'>Facebook</a>",
//    "<a href='https://twitter.com'>Twitter</a>",
//    "<a href='https://github.com'>Github</a>"
//  ]

var objects = sel.objects();
//  [
//    {
//      "tag": "<a href='https://google.com'>Google</a>"
//    }, {
//      "tag": "<a href='https://facebook.com'>Facebook</a>"
//    }, {
//      "tag": "<a href='https://twitter.com'>Twitter</a>"
//    }, {
//      "tag": "<a href='https://github.com'>Github</a>"
//    }
//  ]

var root = sel.root();
//  {
//    "items": [{
//      "tag": "<a href='https://google.com'>Google</a>"
//    }, {
//      "tag": "<a href='https://facebook.com'>Facebook</a>"
//    }, {
//      "tag": "<a href='https://twitter.com'>Twitter</a>"
//    }, {
//      "tag": "<a href='https://github.com'>Github</a>"
//    }]
//  }

---

Usage

In a browser

<script src="st.js"></script>
<script>
var parsed = ST.select({ "items": [1,2,3,4] })
                .transformWith({
                  "{{#each items}}": {
                    "type": "label", "text": "{{this}}"
                  }
                })
                .root();
</script>

In node.js

Install through npm:

$ npm install stjs

Use

const ST = require('st');

const parsed = ST.select({ "items": [1,2,3,4] })
                .transformWith({
                  "{{#each items}}": {
                    "type": "label", "text": "{{this}}"
                  }
                })
                .root();

Learn more at selecttransform.github.io/site

Differences compared to the original

• #concat does not return the template when one of their children did not run the transformation. This makes possible to transform values that originally has constructions of the form {{seems like a template}} as original values, not as templates.
• Templates with array items that evaluates to falsy values (false, 0, "", null, undefined or NaN) are not removed from the result. For example: Having the data { a: "", b: "non empty", c: 0, d: 123 } and the template ["{{a}}", "{{b}}", "{{c}}", "{{d}}"],
  • The original version evaluated to: ["non empty", 123],
  • Whereas the new version evaluates to: ["", "non empty", 0, 123], preserving the array size and element indices.
• Global function JSON.stringify is not overridden so the rest of the projects using this package does not deal with unexpected side effects.
• Updated dev dependencies to fix some vulnerabilities and get latest features and fixes.
• ESLint issues fixed.