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diff --git a/src/templating/README.md b/src/templating/README.md index a6df19f6..6699b0e8 100644 --- a/src/templating/README.md +++ b/src/templating/README.md @@ -1,16 +1,27 @@ -# Introduction to Mustach 0.99 +# Introduction to Mustach 1.2 `mustach` is a C implementation of the [mustache](http://mustache.github.io "main site for mustache") template specification. The main site for `mustach` is on [gitlab](https://gitlab.com/jobol/mustach). -The best way to use mustach is to copy the files **mustach.h** and **mustach.c** +The simpliest way to use mustach is to copy the files **mustach.h** and **mustach.c** directly into your project and use it. -Alternatively, make and meson files are provided for building `mustach` and +If you are using one of the JSON libraries listed below, you can get extended feature +by also including **mustach-wrap.h**, **mustach-wrap.c**, **mustach-XXX.h** and +**mustach-XXX.c** in your project (see below for **XXX**) + +- [json-c](https://github.com/json-c/json-c): use **XXX** = **json-c** +- [jansson](http://www.digip.org/jansson/): use **XXX** = **jansson** +- [cJSON](https://github.com/DaveGamble/cJSON): use **XXX** = **cjson** + +Alternatively, make and meson files are provided for building `mustach` and `libmustach.so` shared library. +Since version 1.0, the makefile allows to compile and install different +flavours. See below for details. + ## Distributions offering mustach package ### Alpine Linux @@ -30,6 +41,13 @@ make See http://pkgsrc.se/devel/mustach +## Known projects using Mustach + +This [wiki page](https://gitlab.com/jobol/mustach/-/wikis/projects-using-mustach) +lists the known project that are using mustach and that kindly told it. + +Don't hesitate to tell us if you are interested to be listed there. + ## Using Mustach from sources The file **mustach.h** is the main documentation. Look at it. @@ -38,15 +56,25 @@ The current source files are: - **mustach.c** core implementation of mustache in C - **mustach.h** header file for core definitions +- **mustach-wrap.c** generic wrapper of mustach for easier integration +- **mustach-wrap.h** header file for using mustach-wrap - **mustach-json-c.c** tiny json wrapper of mustach using [json-c](https://github.com/json-c/json-c) -- **mustach-json-c.h** header file for using the tiny JSON wrapper -- **mustach-tool.c** simple tool for applying template files to a JSON file +- **mustach-json-c.h** header file for using the tiny json-c wrapper +- **mustach-cjson.c** tiny json wrapper of mustach using [cJSON](https://github.com/DaveGamble/cJSON) +- **mustach-cjson.h** header file for using the tiny cJSON wrapper +- **mustach-jansson.c** tiny json wrapper of mustach using [jansson](https://www.digip.org/jansson/) +- **mustach-jansson.h** header file for using the tiny jansson wrapper +- **mustach-tool.c** simple tool for applying template files to one JSON file -The file **mustach-json-c.c** is the main example of use of **mustach** core -and it is also a practical implementation that can be used. It uses the library -json-c. (NOTE for Mac OS: available through homebrew). +The file **mustach-json-c.c** is the historical example of use of **mustach** and +**mustach-wrap** core and it is also a practical implementation that can be used. +It uses the library json-c. (NOTE for Mac OS: available through homebrew). -HELP REQUESTED TO GIVE EXAMPLE BASED ON OTHER LIBRARIES (ex: janson, ...). +Since version 1.0, the project also provide integration of other JSON libraries: +**cJSON** and **jansson**. + +*If you integrate a new library with* **mustach**, *your contribution will be +welcome here*. The tool **mustach** is build using `make`, its usage is: @@ -57,14 +85,14 @@ It then outputs the result of applying the templates files to the JSON file. ### Portability Some system does not provide *open_memstream*. In that case, tell your -preferred compiler to declare the preprocessor symbol **NO_OPEN_MEMSTREAM**. +prefered compiler to declare the preprocessor symbol **NO_OPEN_MEMSTREAM**. Example: - gcc -DNO_OPEN_MEMSTREAM + CFLAGS=-DNO_OPEN_MEMSTREAM make ### Integration -The file **mustach.h** is the main documentation. Look at it. +The files **mustach.h** and **mustach-wrap.h** are the main documentation. Look at it. The file **mustach-json-c.c** provides a good example of integration. @@ -76,139 +104,211 @@ If you intend to use specific escaping and/or specific output, the callbacks of the interface **mustach_itf** that you have to implement are: `enter`, `next`, `leave`, `get` and `emit`. -### Extensions - -By default, the current implementation provides the following extensions: +### Compilation Using Make -#### Explicit Substitution +Building and installing can be done using make. -This is a core extension implemented in file **mustach.c**. +Example: -In somecases the name of the key used for substitution begins with a + $ make tool=cjson libs=none PREFIX=/usr/local DESTDIR=/ install + $ make tool=jsonc libs=single PREFIX=/ DESTDIR=$HOME/.local install + +The makefile knows following switches (\*: default): + + Switch name | Values | Description + --------------+---------+----------------------------------------------- + jsonc | (unset) | Auto detection of json-c + | no | Don't compile for json-c + | yes | Compile for json-c that must exist + --------------+---------+----------------------------------------------- + cjson | (unset) | Auto detection of cJSON + | no | Don't compile for cJSON + | yes | Compile for cJSON that must exist + --------------+---------+----------------------------------------------- + jansson | (unset) | Auto detection of jansson + | no | Don't compile for jansson + | yes | Compile for jansson that must exist + --------------+---------+----------------------------------------------- + tool | (unset) | Auto detection + | cjson | Use cjson library + | jsonc | Use jsonc library + | jansson | Use jansson library + | none | Don't compile the tool + --------------+---------+---------------------------------------------- + libs | (unset) | Like 'all' + | all | Like 'single' AND 'split' + | single | Only libmustach.so + | split | All the possible libmustach-XXX.so ... + | none | No library is produced + +The libraries that can be produced are: + + Library name | Content + --------------------+-------------------------------------------------------- + libmustach-core | mustach.c mustach-wrap.c + libmustach-cjson | mustach.c mustach-wrap.c mustach-cjson.c + libmustach-jsonc | mustach.c mustach-wrap.c mustach-json-c.c + libmustach-jansson | mustach.c mustach-wrap.c mustach-jansson.c + libmustach | mustach.c mustach-wrap.c mustach-{cjson,json-c,jansson}.c + +There is no dependencies of a library to an other. This is intended and doesn't +hurt today because the code is small. + +## Extensions + +The current implementation provides extensions to specifications of **mustache**. +This extensions can be activated or deactivated using flags. + +Here is the summary. + + Flag name | Description + -------------------------------+------------------------------------------------ + Mustach_With_Colon | Explicit tag substition with colon + Mustach_With_EmptyTag | Empty Tag Allowed + -------------------------------+------------------------------------------------ + Mustach_With_Equal | Value Testing Equality + Mustach_With_Compare | Value Comparing + Mustach_With_JsonPointer | Interpret JSON Pointers + Mustach_With_ObjectIter | Iteration On Objects + Mustach_With_EscFirstCmp | Escape First Compare + Mustach_With_ErrorUndefined | Error when a requested tag is undefined + -------------------------------+------------------------------------------------ + Mustach_With_AllExtensions | Activate all known extensions + Mustach_With_NoExtensions | Disable any extension + +For the details, see below. + +### Explicit Tag Substitution With Colon (Mustach_With_Colon) + +In somecases the name of the key used for substition begins with a character reserved for mustach: one of `#`, `^`, `/`, `&`, `{`, `>` and `=`. + This extension introduces the special character `:` to explicitly tell mustach to just substitute the value. So `:` becomes a new special character. -#### Value Testing and Comparing +This is a core extension implemented in file **mustach.c**. + +### Empty Tag Allowed (Mustach_With_EmptyTag) -This are a tool extension implemented in file **mustach-json-c.c**. +When an empty tag is found, instead of automatically raising the error +MUSTACH\_ERROR\_EMPTY\_TAG pass it. -These extensions allows you to test the value of the selected key. -They allow to write `key=value` (matching test) or `key=!value` +This is a core extension implemented in file **mustach.c**. + +### Value Testing Equality (Mustach_With_Equal) + +This extension allows you to test the value of the selected key. +It allows to write `key=value` (matching test) or `key=!value` (not matching test) in any query. -The specific comparison extension also allows to compare if greater, -lesser, etc.. than a value. It allows to write `key>value`. +This is a wrap extension implemented in file **mustach-wrap.c**. + +### Value Comparing (Mustach_With_Compare) + +These extension extends the extension for testing equality to also +compare values if greater or lesser. +Its allows to write `key>value` (greater), `key>=value` (greater or equal), +`key<value` (lesser) and `key<=value` (lesser or equal). It the comparator sign appears in the first column it is ignored as if it was escaped. -#### Access to current value +This is a wrap extension implemented in file **mustach-wrap.c**. + +### Interpret JSON Pointers (Mustach_With_JsonPointer) -The value of the current field can be accessed using single dot like -in `{{#key}}{{.}}{{/key}}` that applied to `{"key":3.14}` produces `3.14` -and `{{#array}} {{.}}{{/array}}` applied to `{"array":[1,2]}` produces -` 1 2`. +This extension allows to use JSON pointers as defined in IETF RFC 6901. +If active, any key starting with "/" is a JSON pointer. +This implies to use the colon to introduce JSON keys. -#### Iteration on objects +A special escaping is used for `=`, `<`, `>` signs when +values comparisons are enabled: `~=` gives `=` in the key. -Using the pattern `{{#X.*}}...{{/X.*}}` it is possible to iterate on -fields of `X`. Example: `{{s.*}} {{*}}:{{.}}{{/s.*}}` applied on -`{"s":{"a":1,"b":true}}` produces ` a:1 b:true`. Here the single star -`{{*}}` is replaced by the iterated key and the single dot `{{.}}` is -replaced by its value. +This is a wrap extension implemented in file **mustach-wrap.c**. -### Removing Extensions +### Iteration On Objects (Mustach_With_ObjectIter) -When compiling mustach.c or mustach-json-c.c, -extensions can be removed by defining macros -using option -D. +With this extension, using the pattern `{{#X.*}}...{{/X.*}}` +allows to iterate on fields of `X`. + +Example: -The possible macros are of 3 categories, the global, -the mustach core specific and the mustach-json-c example -of implementation specific. +- `{{s.*}} {{*}}:{{.}}{{/s.*}}` applied on `{"s":{"a":1,"b":true}}` produces ` a:1 b:true` -#### Global macros +Here the single star `{{*}}` is replaced by the iterated key +and the single dot `{{.}}` is replaced by its value. -- `NO_EXTENSION_FOR_MUSTACH` +This is a wrap extension implemented in file **mustach-wrap.c**. - This macro disables any current or future - extensions for the core or the example. +### Error when a requested tag is undefined (Mustach_With_ErrorUndefined) -#### Macros for the core mustach engine (mustach.c) +Report the error MUSTACH_ERROR_UNDEFINED_TAG when a requested tag +is not defined. -- `NO_COLON_EXTENSION_FOR_MUSTACH` +This is a wrap extension implemented in file **mustach-wrap.c**. - This macro remove the ability to use colon (:) - as explicit command for variable substitution. - This extension allows to have name starting - with one of the mustach character `:#^/&{=>` +### Access To Current Value -- `NO_ALLOW_EMPTY_TAG` +*this was an extension but is now always enforced* - Generate the error MUSTACH_ERROR_EMPTY_TAG automatically - when an empty tag is encountered. +The value of the current field can be accessed using single dot. -#### Macros for the implementation example (mustach-json-c.c) +Examples: -- `NO_EQUAL_VALUE_EXTENSION_FOR_MUSTACH` +- `{{#key}}{{.}}{{/key}}` applied to `{"key":3.14}` produces `3.14` +- `{{#array}} {{.}}{{/array}}` applied to `{"array":[1,2]}` produces ` 1 2`. - This macro allows the program to check whether - the actual value is equal to an expected value. - This is useful in `{{#key=val}}` or `{{^key=val}}` - with the corresponding `{{/key=val}}`. - It can also be used in `{{key=val}}` but this - doesn't seem to be useful. +This is a wrap extension implemented in file **mustach-wrap.c**. -- `NO_COMPARE_VALUE_EXTENSION_FOR_MUSTACH` +### Partial Data First - This macro allows the program to compare the actual - value with an expected value. The comparison operators - are `=`, `>`, `<`, `>=`, `<=`. The meaning of the - comparison numeric or alphabetic depends on the type - of the inspected value. Also the result of the comparison - can be inverted if the value starts with `!`. - Example of use: `{{key>=val}}`, or `{{#key>=val}}` and - `{{^key>=val}}` with their matching `{{/key>=val}}`. +*this was an extension but is now always enforced* -- `NO_USE_VALUE_ESCAPE_FIRST_EXTENSION_FOR_MUSTACH` +The default resolution for partial pattern like `{{> name}}` +is to search for `name` in the current json context and +as a file named `name` or if not found `name.mustache`. - This macro fordids automatic escaping of coparison - sign appearing at first column. +By default, the order of the search is (1) as a file, +and if not found, (2) in the current json context. -- `NO_JSON_POINTER_EXTENSION_FOR_MUSTACH` +When this option is set, the order is reverted and content +of partial is search (1) in the current json context, +and if not found, (2) as a file. - This macro removes the possible use of JSON pointers. - JSON pointers are defined in IETF RFC 6901. - If not set, any key starting with "/" is a JSON pointer. - This implies to use the colon to introduce keys. - So `NO_COLON_EXTENSION_FOR_MUSTACH` implies - `NO_JSON_POINTER_EXTENSION_FOR_MUSTACH`. - A special escaping is used for `=`, `<`, `>` signs when - values comparisons are enabled: `~=` gives `=` in the key. +That option is useful to keep the compatibility with +versions of *mustach* anteriors to 1.2.0. + +This is a wrap extension implemented in file **mustach-wrap.c**. + +### Escape First Compare + +This extension automatically escapes comparisons appears as +first characters. + +This is a wrap extension implemented in file **mustach-wrap.c**. + +## Difference with version 0.99 and previous + +### Extensions -- `NO_OBJECT_ITERATION_FOR_MUSTACH` +The extensions can no more be removed at compile time, use +flags to select your required extension on need. - Disable the object iteration extension. That extension allows - to iterate over the keys of an object. The iteration on object - is selected by using the selector `{{#key.*}}`. In the context - of iterating over object keys, the single key `{{*}}` returns the - key and `{{.}}` returns the value. +### Name of functions -- `NO_SINGLE_DOT_EXTENSION_FOR_MUSTACH` +Names of functions were improved. Old names remain but are obsolete +and legacy. Their removal in far future versions is possible. - Disable access to current object value using single dot - like in `{{.}}`. +The table below summarize the changes. -- `NO_INCLUDE_PARTIAL_FALLBACK` + legacy name | name since version 1.0.0 + ------------------+----------------------- + fmustach | mustach_file + fdmustach | mustach_fd + mustach | mustach_mem + fmustach_json_c | mustach_json_c_file + fdmustach_json_c | mustach_json_c_fd + mustach_json_c | mustach_json_c_mem + mustach_json_c | mustach_json_c_write - Disable include of file by partial pattern like `{{> name}}`. - By default if a such pattern is found, **mustach** search - for `name` in the current json context. This what is done - historically and when `NO_INCLUDE_PARTIAL_FALLBACK` is defined. - When `NO_INCLUDE_PARTIAL_FALLBACK` is defined, if the value is - found in the json context, the files `name` and `name.mustache` - are searched in that order and the first file found is used - as partial content. The macro `INCLUDE_PARTIAL_EXTENSION` can - be use for changing the extension added. |