Json generator

caravel/assets/javascripts/datasource.js

@@ -0,0 +1,50 @@
+var $ = window.$ || require('jquery');
+var jsonGenerator = require("./modules/json_generator");
+
+$(document).ready(function () {
+    var $modal = $('#json_gen_modal');
+
+    var getJsonOrWarn = function () {
+        var expression = $('#expression').val().trim();
+        var $alert = $modal.find('#errorMsg');
+        $alert
+            .removeClass('hidden')
+            .hide()
+            .html("");
+        try {
+            var parse_tree = jsonGenerator.parse(expression);
+            return JSON.stringify(parse_tree);
+        } catch (e) {
+            $alert
+                .show()
+                .html(e.message);
+        }
+        return null;
+    };
+
+    $('#convertButton').click(function () {
+        var json = getJsonOrWarn();
+        if (json) {
+            $('#json').val(json);
+            $(this).closest('.modal').modal('hide');
+        }
+    });
+
+    $('#previewButton').click(function () {
+        var $preview = $modal.find('#preview');
+        var json = getJsonOrWarn();
+        $preview.html(json || "");
+    });
+
+    $modal.on('shown.bs.modal', function () {
+        $('#expression').focus();
+    });
+
+    var showJsonGenModal = function () {
+        $modal.modal('show');
+    };
+
+    $.extend(window, {
+        showJsonGenModal: showJsonGenModal
+    });
+});

caravel/assets/javascripts/modules/json_generator.js

@@ -0,0 +1,92 @@
+var jsep = require("jsep");
+
+var capitalize = function (str) {
+    return str.charAt(0).toUpperCase() + str.slice(1);
+};
+
+var convertFuncCall = function (node) {
+    var funcName = node.callee.name;
+    var fieldName = node.arguments[0].name || "";
+    var m = funcName.toLowerCase().match(/^(double|long)?(sum|min|max)$/);
+    if (!m) {
+        throw new Error("Unsupported function call: " + funcName);
+    }
+
+    var varType = m[1] || 'double'; // default to double
+    var funcType = m[2];
+
+    var type = varType + capitalize(funcType);
+
+    return {
+        type: type,
+        name: fieldName,
+        fieldName: fieldName
+    };
+};
+
+var convertField = function (node) {
+    var fieldName = node.name;
+    return {
+        type: "fieldAccess",
+        name: fieldName,
+        fieldName: fieldName
+    };
+};
+
+var convertBinary = function (node) {
+    var op = node.operator;
+    // TODO: Support the "quotient" type
+    if (!/[+\-*\/]/.test(op)) {
+        throw new Error("Unsupported operation: " + op);
+    }
+    return {
+        type: "arithmetic",
+        fn: op,
+        fields: [node.left, node.right].map(function (child) {
+            return convertArithmetic(child);
+        })
+    };
+};
+
+var convertLiteral = function (node) {
+    return {
+        type: "constant",
+        value: node.value
+    };
+};
+
+var arithmeticTokenHandler = {
+    Identifier: convertField,
+    BinaryExpression: convertBinary,
+    Literal: convertLiteral
+};
+
+var convertArithmetic = function (node) {
+    var converter = arithmeticTokenHandler[node.type];
+    if (!converter) {
+        throw new Error("Invalid Expression (" + node.type + ")");
+    }
+    return converter(node);
+};
+
+var parse = function (expression) {
+    expression = expression.trim().replace('\n', '');
+    if (!expression) {
+        throw new Error("Please enter the expression");
+    }
+    var parse_tree = jsep(expression);
+    var converterMap = {
+        CallExpression: convertFuncCall,
+        BinaryExpression: convertArithmetic,
+        Literal: convertArithmetic
+    };
+    var converter = converterMap[parse_tree.type];
+    if (!converter) {
+        throw new Error("Invalid Expression (" + parse_tree.type + ")");
+    }
+    return converter(parse_tree);
+};
+
+module.exports = {
+    parse: parse
+};

caravel/assets/package.json

@@ -58,6 +58,7 @@
     "imports-loader": "^0.6.5",
     "jquery": "^2.2.1",
     "jquery-ui": "^1.10.5",
+    "jsep": "^0.3.0",
     "less": "^2.6.1",
     "less-loader": "^2.2.2",
     "nvd3": "1.8.2",

caravel/assets/webpack.config.js

@@ -10,7 +10,8 @@ var config = {
     explore: APP_DIR + '/javascripts/explore.js',
     welcome: APP_DIR + '/javascripts/welcome.js',
     sql: APP_DIR + '/javascripts/sql.js',
-    standalone: APP_DIR + '/javascripts/standalone.js'
+    standalone: APP_DIR + '/javascripts/standalone.js',
+    datasource: APP_DIR + '/javascripts/datasource.js'
   },
   output: {
     path: BUILD_DIR,

caravel/templates/caravel/models/datasource/edit.html

@@ -0,0 +1,41 @@
+{% extends "appbuilder/general/model/edit.html" %}
+
+{% block content %}
+    {{ super() }}
+    <div class="modal fade" id="json_gen_modal" tabindex="-1" role="dialog">
+        <div class="modal-dialog" role="document">
+            <div class="modal-content css">
+                <div class="modal-header">
+                    <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+                    <h4 class="modal-title" id="myModalLabel">JSON Generator</h4>
+                    <p>Enter the algebraic expression to convert. For example: <br>
+                        <strong>Normal metrics</strong>: longSum(price), doubleMin(price)<br>
+                        <strong>Post Aggregation</strong>: (price/count)*100<br>
+                    </p>
+                </div>
+                <div class="modal-body">
+                    <textarea id="expression" rows="5" cols="60"></textarea>
+                    <p><strong>Preview:</strong></p>
+                    <div class="" id="preview">(Please click the preview button)</div>
+                    <div class="alert alert-danger hidden" id="errorMsg"></div>
+                </div>
+                <div class="modal-footer">
+                    <button type="button" class="btn btn-default" data-dismiss="modal">
+                        Close
+                    </button>
+                    <button type="button" class="btn btn-default" id="previewButton">
+                        Preview
+                    </button>
+                    <button type="button" class="btn btn-default" id="convertButton">
+                        Convert to Json
+                    </button>
+                </div>
+            </div>
+        </div>
+    </div>
+{% endblock %}
+
+{% block tail_js %}
+    {{ super() }}
+    <script src="/static/assets/javascripts/dist/datasource.entry.js"></script>
+{% endblock %}

caravel/views.py

@@ -181,6 +181,10 @@ class DruidMetricInlineView(CompactCRUDMixin, CaravelModelView):  # noqa
             "[Druid Post Aggregation]"
             "(http://druid.io/docs/latest/querying/post-aggregations.html)",
             True),
+        'json': utils.markdown(
+            "You can also use the "
+            "[generator](javascript:showJsonGenModal()) to generate json",
+            True),
     }
 appbuilder.add_view_no_menu(DruidMetricInlineView)
 
@@ -415,6 +419,7 @@ class DruidDatasourceModelView(CaravelModelView, DeleteMixin):  # noqa
         'datasource_name', 'cluster', 'description', 'owner',
         'is_featured', 'is_hidden', 'default_endpoint', 'offset',
         'cache_timeout']
+    edit_template = "caravel/models/datasource/edit.html"
     add_columns = edit_columns
     page_size = 500
     base_order = ('datasource_name', 'asc')