How Can I Extract All Actions from a Parsed HTML Template?
Dec 26, 2024 am 02:58 AMHow to Inspect a Parsed Template for Embedded Actions
Problem Statement
Given a parsed template, how can we retrieve a list of all the actions defined within it?
Solution
Disclaimer: Internal API Usage
Note that the method we'll use, Template.Tree, is not intended for external use. It's exported solely for the internal workings of the html/template package. Relying on it in your code can lead to unexpected behavior in future releases of the package.
Walkthrough
A parsed template is represented internally as a tree (parse.Tree) comprising various nodes. Each node represents a specific element within the template, such as text, fields, function calls, and so on.
To find the actions, we'll traverse this tree recursively, looking for nodes of type parse.NodeAction. These nodes represent non-control actions, such as field evaluations.
Implementation
import ( "fmt" "html/template" "text/template/parse" ) func ListTemplateFields(t *template.Template) []string { return listNodeFields(t.Tree.Root, nil) } func listNodeFields(node parse.Node, results []string) []string { if node.Type() == parse.NodeAction { results = append(results, node.String()) } if listNode, ok := node.(*parse.ListNode); ok { for _, n := range listNode.Nodes { results = listNodeFields(n, results) } } return results }
Example Usage
t := template.Must(template.New("example").Parse(`{{ .name }} {{ .age }}`)) fields := ListTemplateFields(t) fmt.Println(fields)
Output
[{{.name}} {{.age}}]
The above is the detailed content of How Can I Extract All Actions from a Parsed HTML Template?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Effective handling of JSON in Go requires attention to structural labels, optional fields and dynamic analysis. Use the struct tag to customize the JSON key name, such as json:"name"; make sure the fields are exported for access by the json package. Use pointers or omitempty tags when processing optional fields to distinguish between unprovided values ??from explicit zeros. When parsing unknown JSON, map[string]interface{} can be used to extract data with type assertions. The default number will be parsed as float64. json.MarshalIndent can be used to beautify the output during debugging, but the production environment should avoid unnecessary formatting. Mastering these techniques can improve the robustness and ability of your code

Go programs can indeed interact with C code through Cgo, which allows Go to call C functions directly. When using Cgo, just import the pseudo-package "C" and embed C code in the comments above the import line, such as including C function definitions and calling them. In addition, external C library can be linked by specifying link flags such as #cgoLDFLAGS. However, there are many issues to pay attention to when using Cgo: 1. Memory management needs to be processed manually and cannot rely on Go garbage collection; 2. Go types may not match C types, and types such as C.int should be used to ensure consistency; 3. Multiple goroutine calls to non-thread-safe C libraries may cause concurrency problems; 4. There is performance overhead for calling C code, and the number of calls across language boundaries should be reduced. Cgo's lack

Yes,Goapplicationscanbecross-compiledfordifferentoperatingsystemsandarchitectures.Todothis,firstsettheGOOSandGOARCHenvironmentvariablestospecifythetargetOSandarchitecture,suchasGOOS=linuxGOARCH=amd64foraLinuxbinaryorGOOS=windowsGOARCH=arm64foraWindow

Go simplifies the use of pointers and improves security. 1. It does not support pointer arithmetic to prevent memory errors; 2. Automatic garbage collection and management of memory without manual allocation or release; 3. The structure method can seamlessly use values ??or pointers, and the syntax is more concise; 4. Default safe pointers to reduce the risk of hanging pointers and memory leakage. These designs make Go easier to use and safer than C/C, but sacrifice some of the underlying control capabilities.

Go compiles the program into a standalone binary by default, the main reason is static linking. 1. Simpler deployment: no additional installation of dependency libraries, can be run directly across Linux distributions; 2. Larger binary size: Including all dependencies causes file size to increase, but can be optimized through building flags or compression tools; 3. Higher predictability and security: avoid risks brought about by changes in external library versions and enhance stability; 4. Limited operation flexibility: cannot hot update of shared libraries, and recompile and deployment are required to fix dependency vulnerabilities. These features make Go suitable for CLI tools, microservices and other scenarios, but trade-offs are needed in environments where storage is restricted or relies on centralized management.

Goensuresmemorysafetywithoutmanualmanagementthroughautomaticgarbagecollection,nopointerarithmetic,safeconcurrency,andruntimechecks.First,Go’sgarbagecollectorautomaticallyreclaimsunusedmemory,preventingleaksanddanglingpointers.Second,itdisallowspointe

To create a buffer channel in Go, just specify the capacity parameters in the make function. The buffer channel allows the sending operation to temporarily store data when there is no receiver, as long as the specified capacity is not exceeded. For example, ch:=make(chanint,10) creates a buffer channel that can store up to 10 integer values; unlike unbuffered channels, data will not be blocked immediately when sending, but the data will be temporarily stored in the buffer until it is taken away by the receiver; when using it, please note: 1. The capacity setting should be reasonable to avoid memory waste or frequent blocking; 2. The buffer needs to prevent memory problems from being accumulated indefinitely in the buffer; 3. The signal can be passed by the chanstruct{} type to save resources; common scenarios include controlling the number of concurrency, producer-consumer models and differentiation

Go is ideal for system programming because it combines the performance of compiled languages ??such as C with the ease of use and security of modern languages. 1. In terms of file and directory operations, Go's os package supports creation, deletion, renaming and checking whether files and directories exist. Use os.ReadFile to read the entire file in one line of code, which is suitable for writing backup scripts or log processing tools; 2. In terms of process management, the exec.Command function of the os/exec package can execute external commands, capture output, set environment variables, redirect input and output flows, and control process life cycles, which are suitable for automation tools and deployment scripts; 3. In terms of network and concurrency, the net package supports TCP/UDP programming, DNS query and original sets.
