| 1 | // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. |
| 2 | |
| 3 | namespace WixToolset.Extensibility |
| 4 | { |
| 5 | using System.Xml.Linq; |
| 6 | using WixToolset.Extensibility.Data; |
| 7 | using WixToolset.Extensibility.Services; |
| 8 | |
| 9 | /// <summary> |
| 10 | /// Base class for creating a preprocessor extension. |
| 11 | /// </summary> |
| 12 | public abstract class BasePreprocessorExtension : IPreprocessorExtension |
| 13 | { |
| 14 | /// <summary> |
| 15 | /// Context for use by the extension. |
| 16 | /// </summary> |
| 17 | protected IPreprocessContext Context { get; private set; } |
| 18 | |
| 19 | /// <summary> |
| 20 | /// Messaging for use by the extension. |
| 21 | /// </summary> |
| 22 | protected IMessaging Messaging { get; private set; } |
| 23 | |
| 24 | /// <summary> |
| 25 | /// PreprocessHelper for use by the extension. |
| 26 | /// </summary> |
| 27 | protected IPreprocessHelper PreprocessHelper { get; private set; } |
| 28 | |
| 29 | /// <summary> |
| 30 | /// Gets or sets the variable prefixes for the extension. |
| 31 | /// </summary> |
| 32 | /// <value>The variable prefixes for the extension.</value> |
| 33 | public string[] Prefixes { get; protected set; } |
| 34 | |
| 35 | /// <summary> |
| 36 | /// Called at the beginning of the preprocessing of a source file. |
| 37 | /// </summary> |
| 38 | public virtual void PrePreprocess(IPreprocessContext context) |
| 39 | { |
| 40 | this.Context = context; |
| 41 | |
| 42 | this.Messaging = context.ServiceProvider.GetService<IMessaging>(); |
| 43 | |
| 44 | this.PreprocessHelper = context.ServiceProvider.GetService<IPreprocessHelper>(); |
| 45 | } |
| 46 | |
| 47 | /// <summary> |
| 48 | /// Gets the value of a variable whose prefix matches the extension. |
| 49 | /// </summary> |
| 50 | /// <param name="prefix">The prefix of the variable to be processed by the extension.</param> |
| 51 | /// <param name="name">The name of the variable.</param> |
| 52 | /// <returns>The value of the variable or null if the variable is undefined.</returns> |
| 53 | public virtual string GetVariableValue(string prefix, string name) |
| 54 | { |
| 55 | return null; |
| 56 | } |
| 57 | |
| 58 | /// <summary> |
| 59 | /// Evaluates a function defined in the extension. |
| 60 | /// </summary> |
| 61 | /// <param name="prefix">The prefix of the function to be processed by the extension.</param> |
| 62 | /// <param name="function">The name of the function.</param> |
| 63 | /// <param name="args">The list of arguments.</param> |
| 64 | /// <returns>The value of the function or null if the function is not defined.</returns> |
| 65 | public virtual string EvaluateFunction(string prefix, string function, string[] args) |
| 66 | { |
| 67 | return null; |
| 68 | } |
| 69 | |
| 70 | /// <summary> |
| 71 | /// Processes a pragma defined in the extension. |
| 72 | /// </summary> |
| 73 | /// <param name="prefix">The prefix of the pragma to be processed by the extension.</param> |
| 74 | /// <param name="pragma">The name of the pragma.</param> |
| 75 | /// <param name="args">The pragma's arguments.</param> |
| 76 | /// <param name="parent">The parent node of the pragma.</param> |
| 77 | /// <returns>false if the pragma is not defined.</returns> |
| 78 | /// <comments>Don't return false for any condition except for unrecognized pragmas. Throw errors that are fatal to the compile. use core.OnMessage for warnings and messages.</comments> |
| 79 | public virtual bool ProcessPragma(string prefix, string pragma, string args, XContainer parent) |
| 80 | { |
| 81 | return false; |
| 82 | } |
| 83 | |
| 84 | /// <summary> |
| 85 | /// Called at the end of the preprocessing of a source file. |
| 86 | /// </summary> |
| 87 | public virtual void PostPreprocess(IPreprocessResult result) |
| 88 | { |
| 89 | } |
| 90 | } |
| 91 | } |