Merge pull request #5 from AChris07/add-file-content-support

Add support for passing file content as string

trool/README.md

@@ -210,3 +210,28 @@ with multiple values.
 
 - Import property name rules are the same as for JavaScript keys. That means alphanumeric, underscores,
 and dashes. Anything other than characters will throw an error.
+
+- In case you don't have local access to your rules file, or can't otherwise pass a file path, you can use
+`initFromString()` and pass the content of the CSV file as a string instead:
+  ```typescript
+      const factsHolder = {
+          Visitors: [new Visitor(), new Visitor()],
+          Tickets: new Ticket(),
+      };
+
+      const importsHolder = {
+          VisitorTypes: {
+              ADULT: 'Adult',
+              CHILD: 'Child',
+          },
+      };
+
+      try {
+          const s3 = new AWS.S3();
+          const data = await s3.getObject({ Bucket: bucketName, Key: bucketKey });
+
+          const facts = this.setupFactsHolder(visitors, ticketOpt);
+          const trool = new Trool();
+          await trool.initFromString(data.Body, factsHolder, true, importsHolder);
+
+  ```

trool/lib/Trool.ts

@@ -24,7 +24,7 @@ class Trool {
 
 
     /**
-     * Create the decision tables.
+     * Initialize the engine.
      *
      * @param filePath
      * @param facts
@@ -37,14 +37,47 @@ class Trool {
         showLogs?: boolean,
         imports?: IImportsHolder,
     ) {
-        try {
-            this.logger = new Logger(showLogs);
-            const jsonArr = await csvToJson().fromFile(filePath);
-            const allImports = this.setupImports(jsonArr, imports || {});
-            this._decisionTables = this.getTables(jsonArr, facts, allImports);
-        } catch (err) {
-            throw err;
-        }
+        const jsonArr = await csvToJson().fromFile(filePath);
+        this.createDecisionTables(jsonArr, facts, showLogs, imports);
+    }
+
+
+    /**
+     * Initialize the engine with the CSV file content passed as string.
+     *
+     * @param fileContent
+     * @param facts
+     * @param imports
+     * @param showLogs
+     */
+    public async initFromString(
+        fileContent: string,
+        facts: IFactsHolder,
+        showLogs?: boolean,
+        imports?: IImportsHolder,
+    ) {
+        const jsonArr = await csvToJson().fromString(fileContent);
+        this.createDecisionTables(jsonArr, facts, showLogs, imports);
+    }
+
+
+    /**
+     * Create the decision tables.
+     *
+     * @param filePath
+     * @param facts
+     * @param imports
+     * @param showLogs
+     */
+    private createDecisionTables(
+        jsonArr: IRow[],
+        facts: IFactsHolder,
+        showLogs?: boolean,
+        imports?: IImportsHolder,
+    ) {
+        this.logger = new Logger(showLogs);
+        const allImports = this.setupImports(jsonArr, imports || {});
+        this._decisionTables = this.getTables(jsonArr, facts, allImports);
     }