I am trying to setup some properties that I use multiple times in my MSBuild script. I have the following property section:
<PropertyGroup>
<BuildDependsOn>$(BuildDependsOn); MyAfterBuild </BuildDependsOn>
<SubstitutionsFilePath>$(ProjectDir)app.config.substitutions.xml </SubstitutionsFilePath>
<AppConfig>$(TargetPath).config</AppConfig>
<HostConfig>$(TargetDir)$(TargetName).vshost.exe.config</HostConfig>
</PropertyGroup>
When I run this I get the following error:
The expression "#(TargetPath).config" cannot be used in this context. Item lists cannot be concatenated with other strings where an item list is expected. Use a semicolon to separate multiple item lists.
I don't understand this error, as the use of the $(BuildDependsOn) and $(ProjectDir) work fine. And I know the $(TargetXXX) values generate properly as when I put them directly into the Tasks section below, they work fine.
The reason for this problem is that TargetDir is defined as an item list, not a property; presumably to cater to the scenario where your outputs are distributed amongst several output directories?
I came up against this same problem and managed to work around it by using the $(OutDir) property instead of $(TargetDir).
(The OutDir property is defined in Microsoft.Common.Targets (lines 100-102) as a normalised version of the OutputPath defined in your project file.)
First try running your build with the /v:diag option, which will output a lot more information and give you a clue as to what part of the build is failing.
A clue might be in the Microsoft.Common.targets file (located in %SystemRoot%\Microsoft.NET\Framework\v2.0.50727) in the PrepareForBuild target:
<!--
These CreateProperty calls are required because TargetDir and TargetPath are defined
to contain an item list. We want that item list to be expanded so that it can be used
as a regular property value and not as an item-list-with-transform.
-->
<CreateProperty Value="$(TargetDir)">
<Output TaskParameter="Value" PropertyName="TargetDir" />
</CreateProperty>
<CreateProperty Value="$(TargetPath)">
<Output TaskParameter="Value" PropertyName="TargetPath" />
</CreateProperty>
To me this looks like a bug, you can report it at https://connect.microsoft.com/feedback/Search.aspx?SiteID=210.
Related
I'm trying to create a reusable Target in msbuild, following the basic model outlined in How to invoke the same msbuild target twice?
I'm stuck trying to pass a property that I want interpreted as a list. I haven't found an example online that deals with this situation. As I understand it, the problem is that Properties is already treated as a list item, so it doesn't like having a list item passed in as well. Is there a way to get msbuild to pack and unpack the list correctly here?
Msbuild is complaining with:
error MSB4012: The expression "FilesToZip=#(Scripts)" cannot be used in this context. Item lists cannot be concatenated with other strings where an item list is expected. Use a semicolon to separate multiple item lists.
Here's an example caller:
<Target Name="BuildMigrationZip">
<MSBuild Projects="BuildZip.msbuild"
Targets="BuildZip"
Properties="FilesToZip=#(Scripts);OutputZipFile=$(MigrationPackageFilePath);OutputFolder=$(MigrationPackagePath);Flatten=true"/>
<Message Text="Created database migration zip: $(MigrationPackageFilePath)" Importance="high"/>
</Target>
And the base target:
<Target Name="BuildZip">
<MakeDir Directories="$(OutputFolder)"/>
<Zip Files="#(FilesToZip)"
ZipFileName="$(OutputZipFile)"
Flatten="$(Flatten)"
ParallelCompression="false" />
</Target>
I'm basically at the point of just going back to cut and paste for these, although I want to package up a number of zips here.
UPDATE: The same issue applies to setting Inputs on the reusable target. My question up to this point addresses the raw functionality, but it would be nice to keep dependencies working. So for example:
<Target Name="BuildZip"
Inputs="#(FilesToZip)"
Outputs="$(OutputZipFile)">
<MakeDir Directories="$(OutputFolder)"/>
<Zip Files="#(FilesToZip)"
ZipFileName="$(OutputZipFile)"
Flatten="$(Flatten)"
ParallelCompression="false" />
</Target>
They key is to pass the list around as a property. So when your Scripts list is defined as
<ItemGroup>
<Scripts Include="A"/>
<Scripts Include="B"/>
<Scripts Include="C"/>
</ItemGroup>
then you first convert it into a property (which just makes semicolon seperated items, but msbuild knows how to pass this via the Properties of the MSBuild target) then pass it to the target:
<Target Name="BuildMigrationZip">
<PropertyGroup>
<ScriptsProperty>#(Scripts)</ScriptsProperty>
</PropertyGroup>
<MSBuild Projects="$(MSBuildThisFile)" Targets="BuildZip"
Properties="FilesToZip=$(ScriptsProperty)" />
</Target>
(note I'm using $(MSBuildThisFile) here: you don't necessarily need to create seperate build files for every single target, in fact for small targets like yours it's much more convenient to put it in the same file)
Then in your destination target you turn the property into a list again:
<Target Name="BuildZip">
<ItemGroup>
<FilesToZipList Include="$(FilesToZip)"/>
</ItemGroup>
<Message Text="BuildZip: #(FilesToZipList)" />
</Target>
Output:
BuildZip: A;B;C
Update
When working with Inputs, you cannot pass #(FilesToZip) since that expands to nothing because is not a list: it's a property - which happens to be a number of semicolon-seperated strings. And as such, it is usable for Inputs you just have to expand it as the property it is i.e. $(FilesToZip):
<Target Name="BuildZip"
Inputs="$(FilesToZip)"
Outputs="$(OutputZipFile)">
...
</Target>
Output of second run:
BuildZip:
Skipping target "BuildZip" because all output files are up-to-date with respect to the input files.
I want to write a number in a text file using WriteLinesToFile but the task is putting a line feed at the end which causes me trouble when i want to read or combine in other places
Example:
<WriteLinesToFile File="$(TextFile)" Lines="#(BuildNumber)" Overwrite="true"/>
UPDATE as the user comment below:
The problem that I had was that I was using a very simple command in Property to read the content of a file $([System.IO.File]::ReadAllText("$(TextFile)")) and I really want to use this one but it also included the line feed from WriteLinesToFiles. I ended up using similar solution like yours using ReadLinesFromFile.
There is a slight dissconnect between the title and the description. I would have liked to post this "answer" as an edit, but do not have enough reputation points :)
Do you have a problem with the newline at the end of a file, or do you have a problem ignoring that newline? Could you please clarify?
One way how I suppose you could ignore that newline follows.
This small snippet of code writes a build number to a file, then reads it out and then increments the number read by 1.
<Target Name="Messing_around">
<PropertyGroup>
<StartBuildNumber>1</StartBuildNumber>
</PropertyGroup>
<ItemGroup>
<AlsoStartBuildNumber Include="1"/>
</ItemGroup>
<!-- Use a property
<WriteLinesToFile File="$(ProjectDir)test.txt" Lines="$(StartBuildNumber)" Overwrite="true"/>
-->
<WriteLinesToFile File="$(ProjectDir)test.txt" Lines="#(AlsoStartBuildNumber)" Overwrite="true"/>
<ReadLinesFromFile File="$(ProjectDir)test.txt">
<Output
TaskParameter="Lines"
ItemName="BuildNumberInFile"/>
</ReadLinesFromFile>
<PropertyGroup>
<OldBuildNumber>#(BuildNumberInFile)</OldBuildNumber>
<NewBuildNumber>$([MSBuild]::Add($(OldBuildNumber), 1))</NewBuildNumber>
</PropertyGroup>
<Message Importance="high" Text="Stored build number: #(BuildNumberInFile)"/>
<Message Importance="high" Text="New build number: $(NewBuildNumber)"/>
</Target>
And this is what I see
Output:
1>Build started xx/xx/xxxx xx:xx:xx.
1>Messing_around:
1> Stored build number: 1
1> New build number: 2
1>
1>Build succeeded.
If you attempting to read, in an MSBuild Task, a single line containing only a number from a file with a trailing line feed, then you should not have a problem.
As a side note: With the little information at hand I'd assume that BuildNumber is an Item in an ItemGroup. If you have only one build number to deal with, perhaps Property may have been an option. But then, again, I haven't been tinkering with MSBuild for too long. So, I am open to feedback on the Item vs Property issue.
Below is a portion of a MSBuild file that I'm working on:
<ItemGroup>
<Tests Include="$(SolutionDir)\**\bin\$(TestPlatform)\$(Configuration)\*.Tests.dll" />
</ItemGroup>
<PropertyGroup>
<TestProperties>/testcontainer:%(Tests.FullPath)</TestProperties>
</PropertyGroup>
I want to have a property that holds a command line switch. However, when I try to use $(TestProperties) in an Exec Command string, %(Tests.FullPath) is never resolved to the absolute path of the Tests item. Instead, it's always processed literally, as "%(Tests.FullPath)".
Am I doing something wrong or is this a standard MSBuild behavior? If the latter, is there a way for me to workaround this?
Thanks
P.S. - I realize I probably don't need to access the FullPath property since my Include value is an absolute path. However, I'd still like to understand the issue, along with how to handle it.
You have a syntax error. Item lists are referenced via the # character and item meta data is referenced via %. Reference the MSBuild Special Character Reference for details. To access the well known item metadata, you need to apply a transform inside the Property itself.
<ItemGroup>
<Tests Include="MyFile.txt" />
</ItemGroup>
<PropertyGroup>
<TestProperties>/testcontainer:#(Tests->'%(FullPath)')</TestProperties>
</PropertyGroup>
You can find more help here
I'm trying to combine all javascript files in a project during the build process, but it just isn't working for me. Here's what I have:
<Target Name="CombineJS">
<CreateItem Include=".\**\*.js">
<Output TaskParameter="Include" ItemName="jsFilesToCombine" />
</CreateItem>
<ReadLinesFromFile File="#(jsFilesToCombine)">
<Output TaskParameter="Lines" ItemName="jsLines" />
</ReadLinesFromFile>
<WriteLinesToFile File="all.js" Lines="#(jsLines)" Overwrite="true" />
</Target>
MSBuild is throwing an error on the ReadLinesFromFile line saying there's an invalid value for the "File" parameter. (No error when there's only one file to combine)
So, two questions:
What am I doing wrong?
Is there a better way to combine files within an MSBuild task? I ask this question because I know that my current process removes all tabs and blank lines, which for me isn't that big of a deal, but still kind of annoying.
Change line 6 to:
<ReadLinesFromFile File="%(jsFilesToCombine.FullPath)">
The # operator is used when the input is ItemGroup which is essentially a semicolon-delimited list of strings.
The % operator is for expanding ItemGroups into strings (properties).
The ReadLinesFromFileTask you are using to read the files takes a single file as input to the File property (MSDN). You can't use this task to read lines from multiple files at once. You may however be able to use batching to run the task several times for each file.
I'm trying to output the variable from one target, into the parent target which started it. For example,
Target 1 simply calls the task in file 2 and is supposed to be able to use the variable set within that. However, I just can't seem to get it to work (wrong syntax perhaps?). Target 1 looks like this:
<Target Name="RetrieveParameter">
<MSBuild Projects="$(MSBuildProjectFile)" Targets="ObtainOutput" />
<Message Text="Output = $(OutputVar)" />
</Target>
Target 2 is where it reads in the value of the text file and sets it to the property and sets the variable 'OutputVar' to match. This is supposed to be returned to the parent.
<Target Name="ObtainOutput" Outputs="$(OutputVar)">
<ReadLinesFromFile File="output.txt">
<Output TaskParameter="Lines"
PropertyName="OutputVar" />
</ReadLinesFromFile>
</Target>
I'm quite new to MSBuild tasks, so it could well be something obvious. All I want to do is set a variable in one task, and then have that available in the parent task which called it.
Julien has given you the right answer, but not explained why it is correct.
As you're new to MSBuild tasks, I'll explain why Julien's answer is correct.
All tasks in MSBuild have parameters - you will know them as the attributes that you put on the task. Any of these parameters can be read back out by placing an Output element within it. The Output element has three attributes that can be used:
TaskParameter - this is the name of the attribute/parameter on the task that you want to get
ItemName - this is the itemgroup to put that parameter value into
PropertyName - this is the name of the property to put that parameter value into
In your original scripts, you were invoking one from the other. The second script will execute in a different context, so any property or itemgroup it sets only exists in that context. Therefore when the second script completes, unless you have specified some Output elements to capture values they will be discarded.
Note that you can put more than one Output element under a task to capture multiple parameters or just set the same value to multiple properties/itemgroups.
You have to use TargetOutputs of the MSBuild task:
<Target Name="RetrieveParameter">
<MSBuild Projects="$(MSBuildProjectFile)" Targets="ObtainOutput">
<Output TaskParameter="TargetOutputs" ItemName="OutputVar"/>
</MSBuild>
<Message Text="Output = #(OutputVar)" />
</Target>
(More information on MSBuild task.)