- PhantomJS Cookbook
- Rob Friesel
- 234字
- 2021-07-16 11:37:57
Inspecting the version at runtime
This recipe will introduce the global phantom
object in PhantomJS and discuss how we can inspect the version at runtime using the version
property.
Getting ready
To run this recipe, we will need a script that accesses phantom.version
. The script in this recipe is available in the downloadable code repository as recipe01.js
under chapter02
. If we run the provided example script, we must change to the root directory for the book's sample code.
How to do it…
Consider the following script:
console.log('PhantomJS'); console.log(' - major version: ' + phantom.version.major); console.log(' - minor version: ' + phantom.version.minor); console.log(' - patch version: ' + phantom.version.patch); phantom.exit();
Given the preceding script, enter the following at the command line:
phantomjs chapter02/recipe01.js
Our output should look like the following:
PhantomJS - major version: 1 - minor version: 9 - patch version: 2
How it works…
Our script operates by accessing the version
object on the global phantom
object and writing its properties (major
, minor
, and patch
) to the console. The build of PhantomJS will have this metadata built in and exposed through phantom.version
as read-only information.
Although our example is a trivial one, knowing the specific PhantomJS version at runtime can be helpful for building flexible scripts/libraries. For example, knowing the version at runtime can help us target preferred APIs while still falling back on older or deprecated ones in the event that those APIs are not available.
- Django開發(fā)從入門到實(shí)踐
- 實(shí)用防銹油配方與制備200例
- C語言程序設(shè)計(jì)
- GitLab Repository Management
- Flux Architecture
- PhoneGap Mobile Application Development Cookbook
- Jenkins Continuous Integration Cookbook(Second Edition)
- Python之光:Python編程入門與實(shí)戰(zhàn)
- Lighttpd源碼分析
- Python極簡(jiǎn)講義:一本書入門數(shù)據(jù)分析與機(jī)器學(xué)習(xí)
- JavaScript+jQuery網(wǎng)頁特效設(shè)計(jì)任務(wù)驅(qū)動(dòng)教程
- Java Web應(yīng)用開發(fā)項(xiàng)目教程
- Solr權(quán)威指南(下卷)
- Java并發(fā)實(shí)現(xiàn)原理:JDK源碼剖析
- Splunk Essentials