javascript onclick in html confusion

Question

I was going through some java code(which uses playframework) that provides some shopping cart functionality.The html page contains some javascript (it uses jquery) which is something I have very little knowledge of.Looking through the html,I found a table like this

<table>
...
<td> 
<a href="" onclick="return addItem(${item.id});">buy</a>
</td>
...
</table>

(The template uses ${} to get dynamic values thru playframework template language) In the entire code ,the only addItem(itemId) method I could find was in the ShoppingCart class which has this signature

public void addItem(Item item) {
...
}

When I searched for onclick ,I found this page onclick doc,which gives the syntax of onclick as

onclick="SomeJavaScriptCode"

Going thru all the javascript code(it uses jquery and ejohn-templating)I couldn't find any method like 'addItem'

So,how does the onclick work?How would it know which method to invoke?Will it look in the entire code (javascript and java)to find a matching method?

hvgotcodes · Accepted Answer · 2011-09-01 12:11:59Z

3

somewhere you have an addItem method in your javascript code. The code in the html is executing that method, not the addItem method you found in the java code.

answered Sep 1, 2011 at 12:11

hvgotcodes

121k33 gold badges209 silver badges237 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

sushil bharwani · Accepted Answer · 2011-09-01 12:11:33Z

1

First is it would only look for javascript methods and not java methods. Second is you can use debugging in firebug to reach to the method called.

answered Sep 1, 2011 at 12:11

sushil bharwani

30.2k30 gold badges98 silver badges130 bronze badges

1 Comment

Damon Julian Over a year ago

thanks for the firebug suggestion..I found that function .It was embedded in the template and not as a separate js file,and all the time I was looking in the javascripts folder.

Ibolit · Accepted Answer · 2011-09-01 12:14:01Z

1

It is relatively simple. It looks like your Java code is executed on the server side, and the JavaScript (including jQuery) is executed on the client side. So the ${item.id} is executed on the server, and onClick executes whatever javascript code you provide for it on the client side.

answered Sep 1, 2011 at 12:14

Ibolit

9,79010 gold badges60 silver badges111 bronze badges

Comments

Nivas · Accepted Answer · 2011-09-01 12:17:13Z

0

I do not know playframework, but the addItem should be javascript, and public void addItem(Item item) is java code. Both are not related

This addItem javascript function is somewhere. If you are unable to find it in your code base, you can use the console of your browser (or firebug on Firefox) to see this javascript function. Go to the Script tab and search for addItem.

answered Sep 1, 2011 at 12:17

Nivas

18.4k4 gold badges65 silver badges76 bronze badges

Comments

pedrochaves · Accepted Answer · 2011-09-01 12:18:24Z

0

Javascript can't access server side functions unless is via AJAX or something like it. Even then, it doesn't have direct access to the funcions, but to a page that access that.

Look more carefully for that function in your Javascript using firebug, or the google chrome console. It should be there.

answered Sep 1, 2011 at 12:18

pedrochaves

7826 silver badges20 bronze badges

Collectives™ on Stack Overflow

javascript onclick in html confusion

5 Answers 5

Comments

1 Comment

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

1 Comment

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related