Create user accounts that automatically login without using Accounts.createUser on the client.

client-signup.coffee

Template.signup.events(
    'submit form': (e,t) ->

        # Prevent form from submitting.
        e.preventDefault()

        # Grab the user's details.
        user =
            email: t.find('[name="emailAddress"]').value
            password: t.find('[name="password"]').value

        # Create the user's account.
        Meteor.call 'createUserAccount', user, (error) ->

            # If the account is created successfully, log the user in using the credentials
            # from above.
            if error
                alert error.reason
            else
                Meteor.loginWithPassword(user.email, user.password, (error)->
                    alert error.reason if error
                )

)

client-signup.html

<template name="signup">
    <form id="application-signup" class="signup">
        <div class="form-group">
            <label for="emailAddress">Email Address</label>
            <input type="email" name="emailAddress" class="form-control" placeholder="Email Address">
        </div> <!-- end .form-group -->
        <div class="form-group">
            <label for="password">Password</label>
            <input type="password" name="password" class="form-control" placeholder="Password">
        </div> <!-- end .form-group -->
        <div class="form-group">
            <input type="submit" class="btn btn-success" value="Sign Up">
        </div> <!-- end .form-group -->
    </form>
    <p>Already have an account? <a href="{{pathFor 'login'}}">Log In</a>.</p>
</template>

server-accounts.coffee

###
    Accounts
    Server side account creation and manipulation methods.

    Configuration:
    - forbidClientAccountCreation: Disallow client side account creation.

    Methods:
    - createUserAccount: Performs a server-side account creation using the Meteor Accounts Password package.
###

# Configuration:
Accounts.config(
    forbidClientAccountCreation: true
)

# Define Methods
Meteor.methods(

    createUserAccount: (user)->

        # Check values against correct pattern.
        pattern = { email: String, password: String }
        check(user, pattern)

        # Create the user.
        Accounts.createUser(user)
)

What is the purpose of the exception. Is it meant to be handled (i.e. shown on the client) ,is it meant to be put under the sheets and let client validation do it's thing or should it be spewed out in the browser's console?

I am using your code and it seems when password is empty, check throws an Error which I can't catch and is shown in browser console as:

Exception while simulating the effect of invoking 'createUserAccount' Meteor.makeErrorType.errorClass {message: "Match error: One or more properties do not match the schema.", path: "", sanitizedError: Meteor.makeErrorType.errorClass, errorType: "Match.Error", stack: (...)…} Error: Match error: One or more properties do not match the schema.
at SimpleSchema.condition (http://localhost:3000/packages/aldeed_simple-schema.js?8fda161c43c0ba62801a10b0dfcc3eab75c6db88:2450:11)
at checkSubtree (http://localhost:3000/packages/check.js?ac81167b8513b85b926c167bba423981b0c4cf9c:255:17)
at check (http://localhost:3000/packages/check.js?ac81167b8513b85b926c167bba423981b0c4cf9c:67:5)
at Meteor.methods.createUserAccount (http://localhost:3000/both/methods/accounts.js?c418120e76666f0ca774a281caafc39bc2c3a59d:4:27)
at http://localhost:3000/packages/ddp.js?41b62dcceb3ce0de6ca79c6aed088cccde6a44d8:4244:25
at _.extend.withValue (http://localhost:3000/packages/meteor.js?81e2f06cff198adaa81b3bc09fc4f3728b7370ec:949:17)
at _.extend.apply (http://localhost:3000/packages/ddp.js?41b62dcceb3ce0de6ca79c6aed088cccde6a44d8:4235:54)
at _.extend.call (http://localhost:3000/packages/ddp.js?41b62dcceb3ce0de6ca79c6aed088cccde6a44d8:4113:17)
at Object.Template.PasswordRegister.events.submit form (http://localhost:3000/client/views/shared/accounts/accounts.js?ac573d92938a2b3d6107ea19e50065f7ac5d41b3:36:20)
at null. (http://localhost:3000/packages/blaze.js?efa68f65e67544b5a05509804bf97e2c91ce75eb:3147:18)