Add Presto web connector for Tableau

presto-docs/src/main/sphinx/index.rst

@@ -15,4 +15,5 @@ Presto Documentation
     sql
     migration
     develop
+    tableau
     release

presto-docs/src/main/sphinx/tableau.rst

@@ -0,0 +1,27 @@
+*************************
+Web Connector for Tableau
+*************************
+
+Presto web connector for Tableau implements the functions in the Tableau web
+connector API and lets users run queries from Tableau against Presto. You can
+get more info about the Tableau web connector API at
+`<http://community.tableau.com/community/developers/web-data-connectors>`_.
+
+When creating a new web data source Tableau will ask for the URL of the web
+connector, which is
+``http://[presto_coordinator_host]:[port]/tableu/presto-connector.html``
+where ``presto_coordinator_host`` is the hostname that Presto coordinator is
+running on, ``port`` is 8080 by default. When Tableau first loads the Presto
+web connector it will render an HTML form. In this form you need to fill in
+details such as your user name, the catalog and the schema you want to query,
+the data source name, and finally the SQL query to run. After you click
+``Submit`` the query will be submitted to the Presto coordinator and Tableau
+will then create an extract out of the results retrieved from the coordinator
+page by page. After Tableau is done extracting the results of your query you
+can then use this extract for further analysis with Tableau.
+
+.. note::
+     With Presto web connector you can only create Tableau extracts as the web
+     connector API currently doesn't support the live mode.
+
+

presto-main/src/main/resources/webapp/tableu/presto-client.js

@@ -0,0 +1,102 @@
+/**
+        Tableau web connector doc says that it supports: bool, date, datetime, float, int, and string
+        So, fields with complex types are converted to json strings.
+*/
+function StatementClient(connectionData, headerCallback, dataCallback, errorCallback) {
+    this.query = connectionData.query;
+    this.catalog = connectionData.catalog;
+    this.schema = connectionData.schema;
+    this.source = 'Tableau Web Connector';
+    this.user = connectionData.userName;
+    this.sessionParameters = [];
+
+    this.headerCallback = headerCallback;
+    this.dataCallback = dataCallback;
+    this.errorCallback = errorCallback;
+
+    this.currentResults = null;
+    this.valid = true;
+
+    if (!(connectionData.sessionParameters === undefined)) {
+        var parameterMap = JSON.parse(connectionData.sessionParameters);
+        for (var name in parameterMap) {
+          var value = parameterMap[name];
+          this.sessionParameters.push(name + '=' + value);
+        }
+    }
+
+    this.headers = {
+        "X-Presto-User": this.user ? this.user : 'N/A',
+        "X-Presto-Source": this.source,
+        "X-Presto-Catalog": this.catalog,
+        "X-Presto-Schema": this.schema,
+        "X-Presto-Session": this.sessionParameters
+    };
+
+    // lastRecordNumber starts with 0 according to Tableau web connector docs
+    this.submitQuery(0);
+}
+
+StatementClient.prototype.submitQuery = function(lastRecordNumber) {
+    var statementClient = this;
+    $.ajax({
+        type: "POST",
+        url: '/v1/statement',
+        headers: this.headers,
+        data: this.query,
+        dataType: 'json',
+        // FIXME having problems when async: true
+        async: false,
+        error: function(xhr, statusStr, errorStr) {
+            statementClient.errorCallback(xhr.responseText, errorStr);
+        },
+        success: function(response) {
+            statementClient.currentResults = response;
+            statementClient.responseHandler(response, lastRecordNumber);
+        }
+    });
+};
+
+StatementClient.prototype.advance = function(lastRecordNumber) {
+    if (!this.currentResults || !this.currentResults.nextUri) {
+        this.valid = false;
+        return;
+    }
+
+    var statementClient = this;
+    $.ajax({
+        type: "GET",
+        url: this.currentResults.nextUri,
+        headers: this.headers,
+        dataType: 'json',
+        // FIXME having problems when async: true
+        async: false,
+        error: function(xhr, statusStr, errorStr) {
+            statementClient.errorCallback(xhr.responseText, errorStr);
+        },
+        success: function(response) {
+            statementClient.currentResults = response;
+            statementClient.responseHandler(response, lastRecordNumber);
+            if (!(response.data || response.error)) {
+                // no data in this batch, schedule another GET
+                statementClient.advance(lastRecordNumber);
+            }
+        }
+    });
+};
+
+StatementClient.prototype.responseHandler = function(response, lastRecordNumber) {
+    if (response.error) {
+        this.errorCallback(response.error.errorName, response.error.message);
+    }
+
+    if (response.columns) {
+        this.headerCallback(response.columns);
+    }
+
+    if (response.data) {
+        // push the columns first in case we didn't get columns in previous requests
+        this.headerCallback(response.columns);
+        this.dataCallback(response.data, response.columns, lastRecordNumber);
+    }
+}