How to change the state of a variable using a Meteor app and Metamask?

Question

I try to develop a simple app with meteor and metamask. I'm trying to change the state of the "name" variable of this contract throught my app :

contract demo{
    string public name = 'Etienne';

    function changeName(string _newName){
        name = _newName;
    }
}

I can read and display the name variable and use it in a helper with

const myContract = web3.eth.contract(AbiArray).at(contractAddress);

Template.home.helpers({
  name () {
    const template = Template.instance();

    myContract.name(function(err,res){
      TemplateVar.set(template, "name", res);
    })

But how do I use my changeName function ? Something like this nothing happens (change-name is linked to a button):

Template.home.events({
  'click .change-name'(){
    myContract.changeName('Pitouf');
},
})

If I exlpicitely say it is transaction, not a call, I get a transaction in metamask, but the name still reads the same :

Template.home.events({
  'click .change-name'(){
    myContract.changeName('Pitouf').sendTransaction();
},
})

I am pretty sure I am using the wrong arguments… but how?

Answer 1

Found the answer: everything Metamask is asynchronous, so I need a callback function :

  'click .change-name'(){
    myContract.changeName('Pitouf', {gas: 300000},function(){});
},

And it's working !