javascript - React + Backbone application making 2 POSTS instead of 1 -

i have restful todo list implemented react , backbone.

for now, i'm not talking database; have array var mytodos = []; in server.js.
here's server code post (using express):

app.post('/todos', function(req, res) {     var todo = {         id: mytodos.length,         title: req.body.length,         completed: req.body.completed              };      mytodos.push(todo);     console.log('post ' + json.stringify(todo));     res.send(todo); }); 

when add item list, see 2 posts being made reason.

post: {"id":0,"title":"test","completed":false} post: {"id":1,"title":"test","completed":false} 

in chrome dev. mode, see:

put localhost/todos/0 404 (not found) put localhost/todos/1 404 (not found) 

two put requests!

trying reason through - save() called calls sync(). since model doesn't have id yet (only cid), make post request , todo (id = 0) added mytodos updates model on client (adds id attribute). since change detected, save() puts server (<-- may wrong here; not sure if updated model cause put).

this might explain put, not double post.

here save() getting called (under todoapp = react.createclass...:

componentdidupdate: function() {     this.props.todos.foreach(function(todo) {         console.log('componentdidupdate: ' + todo.id); // logs: undefined, 0, 1         todo.save();     }); }, ... save: function(todo, text) {     console.log('save: ' + todo.id); // logged on update     todo.save({title: text});     this.setstate({editing: null}); }, ... } 

why happen?
why putting in addition posting? , why doing twice?

edit:

resolved double post changing create add - reference got help.

the last problem put 404 (not found) item on server. interestingly, put not going through server seems. server logs post. put being logged somewhere else.

i resolved double post changing create add

more event triggering backbone.collection.create call according this syncs server.

in react code, have componentdidupdate calls backbone.model.save tries sending server. here.

because event caused both create , save executed, post firing twice.