Debugging with a PHP Web Application Debug Configuration

Introduction

In this debugging mode, IntelliJ IDEA fully controls the debugging process: it launches the application, opens the browser, and activates the debugging engine according to a PHP Web Application debug configuration.

A PHP Web Application debug configuration tells IntelliJ IDEA the URL address to access the starting page of the application, the browser to open the starting page in, and the debug server configuration to use.

You can also specify the scripts requests to which you want IntelliJ IDEA to ignore during debugging. This approach can be useful, when your application contains scripts that use AJAX. Suppose you have a menu-ajax-script.php that "reloads" a part of your web page. This script works properly so you do not need to debug it. However, this script is still requested during the debugging session. To have incoming connections to this script ignored, add the menu-ajax-script.php script to the skipped paths list. You can also group such scripts into folders and add these folders to the "ignore list".

Preparing the debugging engine

Before you start debugging, make sure that you have a debugging engine installed and configured properly. IntelliJ IDEA supports debugging with two most popular tools: Xdebug and Zend Debugger. These tools cannot be used simultaneously because they block each other. To avoid this problem, you need to update the corresponding sections in the php.ini file as described in Configuring Xdebug and Configuring Zend Debugger.

To open the active php.ini file in the editor:

1. Open the Settings / Preferences Dialog by pressing Ctrl+Alt+S or by choosing File | Settings for Windows and Linux or IntelliJ IDEA | Preferences for macOS, and click PHP under Languages & Frameworks.
2. On the PHP page that opens, click next to the CLI Interpreter field.
3. In the CLI Interpreters dialog box that opens, the Configuration File read-only field shows the path to the active php.ini file. Click Open in Editor.

Setting breakpoints

Breakpoints are source code markers used to trigger actions during a debugging session. Typically, the purpose behind setting a breakpoint is to suspend program execution to allow you to examine program data. However, IntelliJ IDEA can use breakpoints as triggers for a variety of different actions. Breakpoints can be set at any time during the debugging process. Your breakpoints don't affect your source files directly, but the breakpoints and their settings are saved with your IntelliJ IDEA project so you can reuse them across debugging sessions.

1. Place the caret on the desired line of the source code.

   Breakpoints can be set in the PHP context inside *.php, *.html, and files of other types. Only executable lines are valid locations for line breakpoints. Comments, declarations, and empty lines are not valid locations for the

2. Do one of the following:
   • Click the left gutter area at a line where you want to toggle a breakpoint.
   • On the main menu, choose Run | Toggle Line Breakpoint.
   • Press Ctrl+F8.

Creating a debug configuration of the type PHP Web Application

1. Open the Run/Debug Configuration dialog box by doing one of the following:
   • On the main menu, choose Run | Edit Configurations.
   • Press Shift+Alt+F10, then press 0 to display the Edit Configuration dialog box or select the configuration from the pop-up window and press F4.
2. Click on the toolbar or press Insert. From the drop-down list, select the PHP Web Application configuration type. The PHP Web Application dialog box opens.
3. Specify the configuration name.
4. Choose the applicable debug server configuration from the Server drop-down list or click the Browse button . and define a debug server configuration in the Servers dialog box that opens as described in Creating a PHP Debug Server Configuration
5. In the Start URL text box, type the server path to the file that implements the application starting page. Specify the path relative to the server configuration root ( The server configuration root is the highest folder in the file tree on the local or remote server accessible through the server configuration. For in-place servers, it is the project root. ). The read-only field below shows the URL address of the application starting page. The URL address is composed dynamically as you type.
6. Specify the browser to open the application in. Choose a configured browser from the Browser drop-down list or click the Browse button and specify another browser in the Web Browsers dialog box that opens.

Initiating a debugging session and examining the suspended program

1. To start debugging, click the Debug button on the toolbar.
2. As soon as the debugger suspends on reaching the first breakpoint, examine the application by analyzing frames. A frame corresponds to an active method or function call and stores the local variables of the called method or function, the arguments to it, and the code context that enables expression evaluation. All currently active frames are displayed on the Frames pane of the Debug tool window. where you can switch between them and analyze the information stored therein in the Variables and Watches panes. For more details, see the section Examining Suspended Program.
3. Continue running the program and examine its frames as soon as it is suspended again.
   • To control the program execution manually, step through the code using the commands under the Run menu or toolbar buttons: Step Into (F7), Step Out (Shift+F8), Step Over (F8), and others. For more details, see Stepping Through the Program.
   • To have the program run automatically up to the next breakpoint, resume the session by choosing Run | Resume Program or pressing F9

Specifying scripts to skip requests to

This approach can be useful, when your application contains scripts that use AJAX. Suppose you have a menu-ajax-script.php that "reloads" a part of your web page. This script works properly so you do not need to debug it. However, this script is still requested during the debugging session. To have incoming connections to this script ignored, add the menu-ajax-script.php script to the skipped paths list. You can also group such scripts into folders and add these folders to the "ignore list".

1. Open the Settings / Preferences Dialog by pressing Ctrl+Alt+S or by choosing File | Settings for Windows and Linux or IntelliJ IDEA | Preferences for macOS. Expand the PHP node under Languages & Frameworks, and then click Skipped Paths under Debug.
2. On the Skipped Paths page that opens, configure an "ignore list" of scripts and folders with scripts not to be invoked if IntelliJ IDEA receives incoming connections to them.
   • To add a new entry to the list, click the Add button or press Alt+Insert. Then click the Browse button and in the dialog box that opens choose the file or folder to skip connections to.
   • To remove an entry from the list, select it and click the Remove button or press Alt+Delete. The script will be now executed upon receiving requests to it.
3. To have IntelliJ IDEA inform you every time it receives a request to a script to be skipped, select the Notify about skipped paths check box.