I'm trying to execute a stored function from mongodb-native/node.js environment.
I have several functions inside db.system.js.
It seems Db.executeCommand() is the function but I have no idea how can I pass the function name and the arguments.
I tried db.eval() as suggested but I got the following.
> db.eval('getValue()', {}, function(er,doc) {console.log(er);console.log(doc);});
{ stack: [Getter/Setter], arguments: [ 'send', undefined ], type: 'non_object_property_call', message: [Getter/Setter] }
null
getValue is a simple function that returns an integer.
Anyone has an idea? Thanks.
Assuming db is your open database handler:
db.eval("myFunction(param, param_n)", function(error, result) { });
Looks like you can pass the parameters in separately, too. https://github.com/christkv/node-mongodb-native/blob/master/lib/mongodb/db.js
There you go:
function testDB(req,res) {
MongoClient.connect(url, function(err, db) {
if (err) {
console.log(err);
res.send('connection failed');
} else {
db.eval("testFunction()", function(err, output) {
if(err){
console.log("ERROR: "+err);
res.send(err);
return;
}else{
res.send(output);
return;
}
});
db.close();
}
});
}
I am assuming that you call it for a rest API.
You can change the function params based on your need.
Also I assume your URL has enough permissions to call the function.
If not, use a mongo tool like RoboMongo and change the permission to the user.
It's because you are thinking it will return value , This is asynchronous call , you must pass a callback function with (err,doc) to get the return value
db.eval('addNumbers(4,5)',function(er,doc){
console.log(doc);
})
Related
I have one function in my app getServerData() which I call from home page and passing Token as param in my API calling in this function.
if Token is valid API will return data otherwise it will return unauthorised access with token expired error at that time I am calling same function with new generated token form another API but some how recursive function calling not working in Observable.
Check below code for more detail :
/**
* Get Search result from server.
*/
getServerData(searchText: string): Observable<any> {
let self = this;
return Observable.create(function(observer) {
self.getToken().then((token) => {
console.log('Token : ', token);
self.httpPlugin.get(self.url + searchText, {}, {}).then((response) => {
console.log("Response Success : " + JSON.stringify(response));
observer.next(jsonResponse);
}).catch(error => {
if (error.status == 403) {
//Call Same method Again
self.getServerData(searchText);
} else {
console.log("Error : " + error);
console.log("Error " + JSON.stringify(error));
observer.error(error);
}
});
}).catch((error) => {
observer.error(error);
console.log("Error : " + error);
})
});
}
While calling same function no code execution done.
Edit based on comment:
I am subscribe like below:
this.subscription = this.api.getServerData(this.searchString.toUpperCase()).subscribe((response: any) => {
console.log("back with data :-",response);
}, error => {
console.log("InLine Error : ",error);
});
Not able to understand whats going wrong or Am I doing some mistake in calling function from Observable().
Guide me on this.
Thanks in advance!
It's not good practice to use promise in observable. Use Obserable.fromPromise and also use mergeMap. What will happen if you will use. Whenever any error will come Observable will throw error and you will able to catch. I will suggest to use Subject rather than creating your own observable and also remember one thing that don't subscribe in your service.
Hope it will help
Finally after lots of research I found solution of my issue.
1st thing was I need to update my rxjx library as my installed version of rxjx was 5.5.2 so I upgraded it to latest one 5.5.11.
2nd thing was I am calling Observable without subscribe() to that Observable so it will never return so I updated my recursive call from error block from where I call its subscriber() like below.
getSearchData(){
this.subscription = this.api.getServerData(this.searchString.toUpperCase()).subscribe((response: any) => {
console.log("back with data :-",response);
}, error => {
if (response.status == 403) {
this.getSearchData();
}else{
console.log("InLine Error : ",response);
this.showAlert('Error', 'Something went wrong. please try again.');
}
});
}
By doing above 2 things I am able to solve my issue.
Thanks all for your quick reply on my issue.
Hope this will help someone who is facing same issue like me.
When user refresh a certain page, I want to set some initial values from the mongoDB database.
I tried using the onRendered method, which in the documentation states will run when the template that it is run on is inserted into the DOM. However, the database is not available at that instance?
When I try to access the database from the function:
Template.scienceMC.onRendered(function() {
var currentRad = radiationCollection.find().fetch()[0].rad;
}
I get the following error messages:
Exception from Tracker afterFlush function:
TypeError: Cannot read property 'rad' of undefined
However, when I run the line radiationCollection.find().fetch()[0].rad; in the console I can access the value?
How can I make sure that the copy of the mongoDB is available?
The best way for me was to use the waitOn function in the router. Thanks to #David Weldon for the tip.
Router.route('/templateName', {
waitOn: function () {
return Meteor.subscribe('collectionName');
},
action: function () {
// render all templates and regions for this route
this.render();
}
});
You need to setup a proper publication (it seems you did) and subscribe in the route parameters. If you want to make sure that you effectively have your data in the onRendered function, you need to add an extra step.
Here is an example of how to make it in your route definition:
this.templateController = RouteController.extend({
template: "YourTemplate",
action: function() {
if(this.isReady()) { this.render(); } else { this.render("yourTemplate"); this.render("loading");}
/*ACTION_FUNCTION*/
},
isReady: function() {
var subs = [
Meteor.subscribe("yoursubscription1"),
Meteor.subscribe("yoursubscription2")
];
var ready = true;
_.each(subs, function(sub) {
if(!sub.ready())
ready = false;
});
return ready;
},
data: function() {
return {
params: this.params || {}, //if you have params
yourData: radiationCollection.find()
};
}
});
In this example you get,in the onRendered function, your data both using this.data.yourData or radiationCollection.find()
EDIT: as #David Weldon stated in comment, you could also use an easier alternative: waitOn
I can't see your collection, so I can't guarantee that rad is a key in your collection, that said I believe your problem is that you collection isn't available yet. As #David Weldon says, you need to guard or wait on your subscription to be available (remember it has to load).
What I do in ironrouter is this:
data:function(){
var currentRad = radiationCollection.find().fetch()[0].rad;
if (typeof currentRad != 'undefined') {
// if typeof currentRad is not undefined
return currentRad;
}
}
Before storing data to database I must modify string . Here's my code
beforeCreate:function(value )
{
value.text = value.text.replace(/(\t|\n)/g, '');
}
How to add callback to this function? I know that there must participate callback.
I believe this should do it:
beforeCreate: function(values, callback) {
values.text = values.text.replace(/(\t|\n)/g, '');
return callback();
}
You can refer to the docs for more examples.
I kept having this error when i deploy my app onto meteor cloud server.
Meteor code must always run within a Fiber
at _.extend.get (app/packages/meteor/dynamics_nodejs.js:14:13)
at _.extend.apply (app/packages/livedata/livedata_server.js:1268:57)
at _.extend.call (app/packages/livedata/livedata_server.js:1229:17)
at Meteor.startup.Meteor.methods.streamTwit (app/server/server.js:50:24)
however, I have already wrapped within Fibers
streamTwit: function (twit){
var userid = '1527228696';
twit.stream(
'statuses/filter',
{ follow: userid},
function(stream) {
stream.on('data', function(tweet) {
Fiber(function(){
if(tweet.user.id_str === userid)
{
Meteor.call('addQn', tweet);
}
}).run();
console.log(tweet);
console.log('---------------------------------------------------------');
console.log(tweet.user.screen_name);
console.log(tweet.user.name);
console.log(tweet.text);
});
}
);
}
I don't know what's the reason but someone suggested that i should wrap it with Meteor.bindEnvironment instead. Hence, I did this:
streamTwit: function (twit){
this.unblock(); // this doesn't seem to work
console.log('... ... trackTweets');
var _this = this;
var userid = '1527228696';
twit.stream(
'statuses/filter',
{ follow: userid},
function(stream) {
stream.on('data', function(tweet) {
Meteor.bindEnvironment(function () {
if(tweet.user.id_str === userid)
{
Meteor.call('addQn', tweet);
}
}, function(e) {
Meteor._debug("Exception from connection close callback:", e);
});
console.log(tweet);
console.log('---------------------------------------------------------');
console.log(tweet.user.screen_name);
console.log(tweet.user.name);
console.log(tweet.text);
});
}
);
}
//add question method
addQn:function(tweet){
questionDB.insert({'tweet': tweet, 'date': new Date()});
}
but now it doesn't even work. I realise that this only happened when I tried to insert some data into mongodb.
May I know what is the problem with my code? Thanks!
All these codes were written in app/server/server.js
You shouldn't need to use Meteor.call on the server side. That is for client-side code only. Just call addQn directly or better yet, inline it since it's just one line of code.
I've tried to understand this post regarding this concept, however, I'm failing to get it. I have the following simple setup:
/server/test.js
Meteor.methods({
abc: function() {
var result = {};
result.foo = "Hello ";
result.bar = "World!";
return result;
}
});
/client/myapp.js
var q = Meteor.call('abc');
console.log(q);
This structure returns to the console undefined.
If I change the myapp.js file to:
Meteor.call('abc', function(err, data) {
!err ? console.log(data) : console.log(err);
}
I receive the Object in my console.
Ideally this is what I'd like to be able to do, but it doesn't work, stating in the console: Cannot read property 'greeting' of undefined
/client/myapp.js
var q = Meteor.call('abc');
Template.hello.greeting = function() {
return q.foo;
}
Any help in passing the data from the server object into the template would be greatly appreciated. I'm still learning JavaScript & Meteor.
Thanks!
From the Meteor.call documentation:
On the client, if you do not pass a callback and you are not inside a stub, call will return undefined, and you will have no way to get the return value of the method. That is because the client doesn't have fibers, so there is not actually any way it can block on the remote execution of a method.
So, you'll want to do it like this:
Meteor.call('abc', function(err, data) {
if (err)
console.log(err);
Session.set('q', data);
});
Template.hello.greeting = function() {
return Session.get('q').foo;
};
This will reactively update the template once the data is available.
This happens because Npm.require has Async behavior. That's the reason that you have to write a callback for Meteor.call.
But there is a solution, just use install(mrt add npm) and you'll get a function named Meteor.sync(//...) with this you can do both games: sync and async in your Meteor.call().
Reference: http://www.sitepoint.com/create-a-meteor-app-using-npm-module/
You can get the return value of a Meteor method for use in a template by using a reactive variable. Check out the working demonstration on Meteorpad
I went for a ghetto solution. But, it works for me, which is what matters, to me. Below is my code, which, in concept, I think, solves OP's problem.
In the client's main.js:
Meteor.setInterval(function() {
confirmLogin();
}, 5000);
This runs the confirmLogin() function every five seconds.
The confirmLogin function (in the client's main.js):
function confirmLogin() {
Meteor.call('loggedIn', function (error, result) {
Session.set("loggedIn", result);
});
}
The loggedIn method (in the server's main.js):
loggedIn: function () {
var toReturn = false;
var userDetails = Meteor.user();
if (typeof userDetails["services"] !== "undefined") {
if (typeof userDetails["services"]["facebook"] != "undefined") {
toReturn = true;
}
}
return toReturn;
},
The relevant helper:
loggedIn: function () {
return Session.get("loggedIn");
}