Rename HistogramBase by BaseHistogram

2017-09-11 13:53:05 +02:00
parent d75ee965ae
commit 6c3fa045cd
1 changed files with 77 additions and 0 deletions
@@ -0,0 +1,77 @@
+const BaseDataview = require('../base');
+
+const TYPE = 'histogram';
+
+module.exports = class BaseHistogram extends BaseDataview {
+    constructor (query, options, queries) {
+        super();
+
+        if (typeof options.column !== 'string') {
+            throw new Error('Histogram expects `column` in widget options');
+        }
+
+        this.query = query;
+        this.queries = queries;
+        this.column = options.column;
+        this.bins = options.bins;
+
+        this._columnType = null;
+    }
+
+    sql (psql, override, callback) {
+        if (!callback) {
+            callback = override;
+            override = {};
+        }
+
+        if (this._columnType === null) {
+            this.getColumnType(psql, this.column, this.queries.no_filters, (err, type) => {
+                // assume numeric, will fail later
+                this._columnType = 'numeric';
+                if (!err && !!type) {
+                    this._columnType = Object.keys(type).find(function (key) {
+                        return type[key];
+                    });
+                }
+                this.sql(psql, override, callback);
+            }, true); // use read-only transaction
+            return null;
+        }
+
+        return this._buildQuery(psql, override, callback);
+    }
+
+    getType () {
+        return TYPE;
+    }
+
+    toString () {
+        return JSON.stringify({
+            _type: TYPE,
+            _column: this.column,
+            _query: this.query
+        });
+    }
+
+    _getBinEnd (override) {
+        if (override.hasOwnProperty('start') && override.hasOwnProperty('end')) {
+            return Math.max(override.start, override.end);
+        }
+        return override.end || 0;
+    }
+
+    _getBinsCount (override) {
+        return override.bins || 0;
+    }
+
+    _getWidth (override) {
+        let width = 0;
+        const binsCount = override.bins;
+
+        if (binsCount && Number.isFinite(override.start) && Number.isFinite(override.end)) {
+            width = (override.end - override.start) / binsCount;
+        }
+
+        return width;
+    }
+};