Systems and methods of preventing user interface (UI) flickering

1. A method comprising:

receiving, at a computing system, an expression in a formula language to generate a user interface to be displayed, wherein the expression includes a first portion of the expression and a second portion of the expression, wherein the first portion of the expression relies upon a first portion of data to be retrieved from at least one data source communicatively coupled to the computing system, and the second portion of the expression relies upon a second portion of the data to be retrieved from the at least one data source, wherein the expression includes at least one expression key, wherein the at least one expression key is configured to be linked to the at least one data source, and wherein data of the at least one expression key is determined when the user interface is generated to be displayed;

determining, at the computing system, whether a first portion of the data for the first portion of the expression has been retrieved from the at least one data source when the user interface is to be generated based on a signal received by the computing system from the at least one data source; and

outputting, at the computing system, the user interface based on the determination, wherein:

when the first portion of the data is retrieved before the second portion of the data, and the first portion of the expression is evaluated to have a first result, outputting the user interface before the second portion of the data is available; and

when the first portion of the data is retrieved before the second portion of the data, and the first portion of the expression is evaluated to have a second result, delaying the evaluation of the second portion of the expression and the outputting of the user interface until the data for the second portion of data is available.

2. The method of claim 1 , wherein the determining whether the first portion of the data for the expression has been retrieved comprises:

evaluating, at the computing system, the expression which includes the data to be retrieved from the at least one data source; and

returning a value of undefined or an exception when the first portion of data is unavailable from the at least one data source.

3. The method of claim 2 , wherein the outputting the user interface further comprises:

outputting, at the computing system, the user interface without the first portion of data when the value of undefined or the exception is returned.

4. The method of claim 2 , wherein the signal received by the computing system is the undefined value or the exception.

5. The method of claim 1 , further comprising:

retrieving, at the computing system, the first portion of the data and the second portion of the data asynchronously.

6. A system comprising:

a computing system having a processor and a memory that is configured to:

receive an expression in a formula language to generate a user interface to be displayed, wherein the expression includes a first portion of the expression and a second portion of the expression, wherein the first portion of the expression relies upon a first portion of data to be retrieved from at least one data source communicatively coupled to the computing system, and the second portion of the expression relies upon a second portion of the data to be retrieved from the at least one data source, wherein the expression includes at least one expression key, wherein the at least one expression key is configured to be linked to the at least one data source, and wherein data of the at least one expression key is determined when the user interface is generated to be displayed;

determine whether a first portion of the data for the first portion of the expression has been retrieved from the at least one data source when the user interface is to be generated based on a signal received by the computing system from the at least one data source; and

output the user interface based on the determination, wherein:

when the first portion of the data is retrieved before the second portion of the data, and the first portion of the expression is evaluated to have a first result, output the user interface before the second portion of the data is available; and

when the first portion of the data is retrieved before the second portion of the data, and the first portion of the expression is evaluated to have a second result, delay the evaluation of the second portion of the expression and the output of the user interface until the data for the second portion of data is available.

7. The system of claim 6 , wherein the computing system determines whether the first portion of the data for the expression has been retrieved by evaluating the expression which includes the data to be retrieved from the at least one data source, and returning a value of undefined or an exception when the first portion of data is unavailable from the at least one data source.

8. The system of claim 7 , wherein the computing system outputs the user interface without the first portion of data when the value of undefined or the exception is returned.

9. The system of claim 7 , wherein the signal received by the computing system is the undefined value or the exception.

10. The system of claim 6 , wherein the computing system retrieves the first portion of the data and the second portion of the data asynchronously.