Tags

#Introduction

#How you can add tags

• use static files containing key/value pairs
• use the method addTag()

#What you can define

You can replace

• simple static placeholders
• placeholders with variables

#How to add replacements

#Files

You can write replacements in one or multiple text files and load them with

$oReplace=new axelhahn\ReplaceTags();
$oReplace->readTagfile(<FILE_1>);
$oReplace->readTagfile(<FILE_N>);

You get the idea: in files you can group your replacements and import only the needed files.

The syntax is:

; I am a comment
[Tag] := [Replacement]

Rules:

• Lines starting with ; are comments and will be ignored
• Tag is the part in front of the devider; spaces will be trimmed.
• The devider is always :=
• The replacement
  • is the part behind the devider
  • spaces will be trimmed.
  • can be multiline

#By method addTag()

You can add replacements with the method addTag(). With it you can add more replacements. It can be used if you have dynamic output data that cannot be written in a static file.

The syntax is:

$oReplace=new axelhahn\ReplaceTags();
// optional:
// $oReplace->readTagfile(<FILE_1>);
$this->addTag('{{PROJECT_VERSION}}', $this->_sVersion);

#What you can define

#Simple static placeholders

This is the mos simple variant: you define a strng that will be replaced with something else.

To prevent worng replaces you need to define a keyword that is somehow uniqe in your texts.

Recommendation:

Surround a string somehow - eg. with an double underscore like __PROJECTID__ (for project name) or brackets {{PROJECTID}}

#Overrides

If you imagine that all replacements are handled top down. You should define the most simple keywords first. In a later replacement you can use already defined keys as a variable.

A small example illustrates this:

__PRJ__     := ahcrawler
__URLGIT__  := https://github.com/axelhahn/__PRJ__.git
__URLZIP__  := https://github.com/axelhahn/__PRJ__/archive/refs/heads/master.zip

#Placeholders with variables

Next to the simple static placeholders you can use variables.

Syntax:

;   with arguments: use double quotes and introduce a variable with "$" 
;   character:
[Tag "$arg1[,..$argN]"] := [Replacement_with_$arg1...$argN]

• In your key (before the delimter :=) use double quotes
• Inside these double quotes you can use $ and a string for a variable like $<VARNAME>
• You also can use multiple variables: use a ,as delimiter like $<VARNAME1>,$<VARNAME2>
• Override: in dependency of the count of variables the right replacement ()

EXAMPLE:

We define a wrapper [IMG "..."] for an image tag in a file.

[IMG "$img"]    := 

		<!-- image with alt text -->
		<br />
		<img src="$img" class="screenshot" alt="image $img"><br />


[IMG "$img,$alt"]    := 

		<!-- image with alt text -->
		<br />
		<img src="$img" class="screenshot" alt="$alt"><br />

If your source content you can use now both variants: [img ".."] with one or two arguments:

[img "/asstes/images/example.png"]
[img "/asstes/images/example.png","My alt title"]