Finding out JavaScript error on Visualforce page

 Hi All, In this post I am going to explain you all how we can able to find out the JavaScript code error which we written on visulforce page.we may use different JavaScript methods or codes for different functionality in visualforce page, while saving that visualforce page we will get only compiler error on apex tag but not on JavaScript code or other codes which we used on the pages.

To give demo I have created the page called 'JavaScriptErrorDemo' .

Below is the page:

Understanding Trigger Context Variable

When I started my carrier as Salesforce developer.when I wrote my first trigger code, I always use to hear "first understand and Trigger.old"(Trigger context variable) from senior colleague in my team. Then I started searching for what, trigger.old and other context variable will return in trigger, whether there is any practical experiment for this, but I didn't get any. 

This is only one Salesforce site helped me to understand theoretically.

Dynamically querying fields by passing object name dynamically

 First you need to know why this topic, as a developer I got tension when I developing an application.In controller mostly we use fields API while querying the fields from

objects till now I used the SOQl query [select Name, CreatedDate, pincode__c from Object] like this it will work fine.

But the problem here it is, if I want to change the properties of the custom fields or delete the custom fields Salesforce will through the custom field validation error like the field is reference this apex class and page etc mostly classes.

Enable Chatter Widget on Visualforce page

Everybody knows, now chatter widget is available to collaborate with the peoples or a group of people in your company. To enable the chatter widget to the users you should have "Customize Application" permission, if you have this permission follow the below steps.

Your Name-->Setup-->Customize-->Chatter-->Chat Setting

Now you are on the page to enable the chatter widget.You can see there is a two option

    1. Chat Setting.
    2. Visualforce Setting.

What is Chatter?

What is Chatter?


 Chatter is a brand-new way to collaborate at work. Because status information about people and important projects is automatically pushed to users, Chatter makes it easy connect with the people and information they care about most.