I have just tried the following =IIF(Fields!MyID.Value > 0, True, False) in Report Builder and it works fine. Try returning "SomeFieldValue" as an integer either at the database or dataset level.
For instance in your dataset query, cast SomeFieldValue to an int and then in the column visibility expression try:
=IIF(Fields!SomeFieldValue.Value > 0, True, False)
This is perhaps more then you asked for but I have a snipplet (even though it's quite long) for doing RPC using node-amqp instead of REQ/RES with rabbit.js. What I have done is similar to what you could find in the RabbitMQ tutorial about RPC
For the moment the content in the message should be an object (hash) that will get transformed by the amqp module to json.
The AmqpRpc class take an amqp connection when initialized then it should only be a matter of calling makeRequest and wait for a response in the callback.
The response have the form of function(err, response) where err might be a timeout error
I'm sorry its not exactly what you asked for but it's maybe close enough.
I also posted the code as a gist on github: https://gist.github.com/2720846
Edit:
Samples changed to support multiple outstanding requests.
amqprpc.js
var amqp = require('amqp')
, crypto = require('crypto')
var TIMEOUT=2000; //time to wait for response in ms
var CONTENT_TYPE='application/json';
exports = module.exports = AmqpRpc;
function AmqpRpc(connection){
var self = this;
this.connection = typeof(connection) != 'undefined' ? connection : amqp.createConnection();
this.requests = {}; //hash to store request in wait for response
this.response_queue = false; //plaseholder for the future queue
}
AmqpRpc.prototype.makeRequest = function(queue_name, content, callback){
var self = this;
//generate a unique correlation id for this call
var correlationId = crypto.randomBytes(16).toString('hex');
//create a timeout for what should happen if we don't get a response
var tId = setTimeout(function(corr_id){
//if this ever gets called we didn't get a response in a
//timely fashion
callback(new Error("timeout " + corr_id));
//delete the entry from hash
delete self.requests[corr_id];
}, TIMEOUT, correlationId);
//create a request entry to store in a hash
var entry = {
callback:callback,
timeout: tId //the id for the timeout so we can clear it
};
//put the entry in the hash so we can match the response later
self.requests[correlationId]=entry;
//make sure we have a response queue
self.setupResponseQueue(function(){
//put the request on a queue
self.connection.publish(queue_name, content, {
correlationId:correlationId,
contentType:CONTENT_TYPE,
replyTo:self.response_queue});
});
}
AmqpRpc.prototype.setupResponseQueue = function(next){
//don't mess around if we have a queue
if(this.response_queue) return next();
var self = this;
//create the queue
self.connection.queue('', {exclusive:true}, function(q){
//store the name
self.response_queue = q.name;
//subscribe to messages
q.subscribe(function(message, headers, deliveryInfo, m){
//get the correlationId
var correlationId = m.correlationId;
//is it a response to a pending request
if(correlationId in self.requests){
//retreive the request entry
var entry = self.requests[correlationId];
//make sure we don't timeout by clearing it
clearTimeout(entry.timeout);
//delete the entry from hash
delete self.requests[correlationId];
//callback, no err
entry.callback(null, message);
}
});
return next();
});
}
A small example on how to use it can be found below. Save both code parts and just run with...
node client.js
If you don't have a server to provide the reply the request will time out.
client.js
//exmaple on how to use amqprpc
var amqp = require('amqp');
var connection = amqp.createConnection({host:'127.0.0.1'});
var rpc = new (require('./amqprpc'))(connection);
connection.on("ready", function(){
console.log("ready");
var outstanding=0; //counter of outstanding requests
//do a number of requests
for(var i=1; i<=10 ;i+=1){
//we are about to make a request, increase counter
outstanding += 1;
rpc.makeRequest('msg_queue', {foo:'bar', index:outstanding}, function response(err, response){
if(err)
console.error(err);
else
console.log("response", response);
//reduce for each timeout or response
outstanding-=1;
isAllDone();
});
}
function isAllDone() {
//if no more outstanding then close connection
if(outstanding === 0){
connection.end();
}
}
});
I'll even throw in a sample server for good measure
server.js
//super simple rpc server example
var amqp = require('amqp')
, util = require('util');
var cnn = amqp.createConnection({host:'127.0.0.1'});
cnn.on('ready', function(){
console.log("listening on msg_queue");
cnn.queue('msg_queue', function(q){
q.subscribe(function(message, headers, deliveryInfo, m){
util.log(util.format( deliveryInfo.routingKey, message));
//return index sent
cnn.publish(m.replyTo, {response:"OK", index:message.index}, {
contentType:'application/json',
contentEncoding:'utf-8',
correlationId:m.correlationId
});
});
});
});
Best Answer
I tried the example that you have provided and the only difference is that you have True and False values switched as
@bdparrish
had pointed out. Here is a working example of making an SSRS Texbox visible or hidden based on the number of rows present in a dataset. This example usesSSRS 2008 R2
.Step-by-step process:
SSRS 2008 R2
In this example, the report has a dataset named
Items
and has textbox to show row counts. It also has another textbox which will be visible only if the dataset Items has rows.Right-click on the textbox that should be visible/hidden based on an expression and select
Text Box Properties...
. Refer screenshot #1.On the
Text Box Properties
dialog, click onVisibility
from the left section. Refer screenshot #2.Select
Show or hide based on an epxression
.Click on the expression button
fx
.Enter the expression
=IIf(CountRows("Items") = 0 , True, False)
. Note that this expression is to hide the Textbox (Hidden).Click OK twice to close the dialogs.
Screenshot #3 shows data in the SQL Server table
dbo.Items
, which is the source for the report data setItems
. The table contains 3 rows. Screenshot #4 shows the sample report execution against the data.Screenshot #5 shows data in the SQL Server table
dbo.Items
, which is the source for the report data setItems
. The table contains no data. Screenshot #6 shows the sample report execution against the data.Hope that helps.
Screenshot #1:
Screenshot #2:
Screenshot #3:
Screenshot #4:
Screenshot #5:
Screenshot #6: